England and Wales High Court (Technology and Construction Court) Decisions

IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
Technology and Construction Court

		St Dunstan's House, 131 – 137 Fetter Lane, London, EC4A 1HD
		18 September 2009

Judge Thornton QC:

A. Introduction

1. In this action, the claimant, Mr Timothy Crowley, trading as Crowley Civil Engineers ("Crowley"), is claiming a contribution from the defendant, Rushmoor Borough Council ("Rushmoor") under section 1(1) of the Civil Liability (Contribution) Act 1978 ("CLCA"). The claim arises out of the settlement of the main action in which Rushmoor was the first defendant and Crowley was the second defendant. The claimants in the main action were four members of the Sampla family ("the claimants") whose end of terrace house, Number 80 Queen's Road, Aldershot, Hampshire ("Number 80"), partially collapsed on 5 July 2002. This collapse occurred when paving work was being carried out on a public open space owned by Rushmoor that was located immediately adjacent to the exposed flank wall of Number 80. This work was being carried out by Crowley for Rushmoor and it caused a significant withdrawal of support to the flank wall foundations of Number 80. In the main action, the claimants claimed that the partial collapsed was caused by the negligence of both Rushmoor and Crowley and claimed damages based on the extensive cost of rebuilding and reinstating Number 80, the value of their possessions that were lost or damaged by the partial collapse and all the other resulting direct and consequential losses that had occurred. Both Crowley and Rushmoor had, when serving their respective defences in the main action, joined into those defences an additional claim against the other defendant seeking contribution for any liability to the claimants that that defendant might incur.
2. In the main action, the claimants originally claimed a total sum well in excess of £300,000. The action was compromised by Crowley agreeing to pay the claimants £384,500 and their assessed costs incurred in the main action. Rushmoor declined to pay anything towards this compromise which was finalised by a consent order dated 25 September 2008. The effect of this compromise was to stay the main action against both Crowley and Rushmoor. This order also provided that Crowley and Rushmoor's respective contribution claims would continue even though the main action had been stayed. In consequence, Crowley has continued with its CCLA contribution claim and now claims from Rushmoor such part of its liability to the claimants under the compromise as the court determines to be fair and reasonable for Rushmoor to fund. Crowley contends that by far the greater part of this liability should be funded by Rushmoor whereas Rushmoor, in its defence, maintains that it should fund no, or only a very small, part of this liability.
3. No contemporaneous measurements were taken of the site before or after the collapse, no site survey was undertaken and no trial pits were dug prior to work being started. Various photographs were taken of the exposed foundations during the course of the work and of Number 80 in its damaged state after the collapse. My findings in relation to the topography of the site and the details of Number 80 and its foundations are based on the following sources of evidence:

(1) The photographs taken by the experts and by Mr Simpson;

(2) The evidence and recollections of the three witnesses who had any first hand knowledge of the site and the work:

(i) Mr Crowley, Crowley's sole proprietor;

(ii) Mr Ward, one of Crowley's general labourers who was also the machine driver and in charge of the work on site; and

(iii) Mr Simpson, Rushmoor's Highways Engineer who was responsible for the paving work on Rushmoor's behalf;

(3) The measurements, site observations of the site in its rebuilt state and deductions from the photographs and other relevant documents made by one or more of the three experts who were instructed in this case being:

(i) Dr Love a civil engineer instructed on behalf of the claimants;

(ii) Mr Vincent a chartered building surveyor instructed on behalf of Crowley; and

(iii) Mr Whiting, a chartered surveyor instructed on behalf of Rushmoor;

(4) The joint statement signed by all three experts and dated 20 June 2008; and

(5) Data obtained by Dr Love and Mr Vincent from a report prepared by Richard Jackson plc ("RJP"), consultants appointed by the claimants' insurers to design and superintend the reconstruction works.

B. Issues

4. In the main action, the claimants alleged that both Crowley and Rushmoor had caused the withdrawal of support and consequent collapse of part of Number 80 on a variety of grounds based on negligence, negligently caused nuisance and interference with Number 80's easement of support. Crowley accepted in its defence in the main action that it negligently caused this withdrawal in relatively insignificant respects but, otherwise, all the allegations of both breach and causation were denied by both parties. However, both Crowley and Rushmoor have adopted, and now pursue, the claimants' allegations against the other. There are significant disagreements between both parties as to the material facts and as to aspects of the expert evidence. All these disagreements therefore give rise to issues as to the material facts and expert evidence, as to each party's breaches of duty owed to the claimants, as to causation and as to the contribution that each party should make towards the compromise of the main action. The compromise itself is not in dispute since Rushmoor accepts that the compromise and all its terms are reasonable.
5. The partial collapse and the resulting damage occurred because the ground adjacent to the exposed flank wall of Number 80 had been excavated to depths below its foundations so as to enable Crowley to lay a sub-base for, and then the paving of, the public open space following the removal of a planter that was providing structural support for those foundations. This exposure extended to depths below the foundations ranging from 130mm to 400mm. The first group of issues is concerned with the original design and execution of the work. Crowley contends that the foundations were unusually and unexpectedly shallow and were supported structurally by the planter, that Rushmoor should have undertaken a pre-contract site investigation which would have revealed the shallow nature of the foundations and the full extent of the support provided by the planter and that no collapse would have occurred had it been known before work started that special measures would have to be taken to protect the foundations temporarily during the excavation work and permanently thereafter. Rushmoor contends that no such investigation was necessary and that the exposure of the foundations and subsequent collapse only occurred because of Crowley's negligent over-excavation of the site.
6. The second group of issues arise as a result of Crowley's subsequent attempt to prevent the foundations from being undermined following their full exposure and the consequent dangerous undermining of the flank wall. At that point, Mr Simpson, Rushmoor's Highways Manager, verbally instructed Crowley to implement supportive measures. It is accepted by both parties that the measures that Crowley started to implement were dangerously inappropriate and that the different measures that Mr Simpson stated in evidence that he had instructed Crowley to implement were appropriate and might well have saved Number 80 from partial collapse. Crowley denies that Mr Simpson instructed the appropriate measures that Mr Simpson stated in evidence that he had instructed and contends that he actually instructed it to undertake the dangerously inappropriate measures that it was in the process of implementing when the partial collapse occurred. There is, therefore, a significant dispute as to what measures Mr Simpson actually instructed Crowley to implement.
7. Crowley's case in summary is that it is not liable for the consequences of its partial implementation of a dangerously inappropriate supportive scheme. It contends that Mr Simpson was negligent in devising and then instructing it to implement this work and that he now wrongly asserts that he instructed different and safe work so as to cover up his original negligence. Moreover, Crowley had no option but to follow Mr Simpson's original instructions given the terms of its contract with Rushmoor. In consequence, Rushmoor is solely responsible for the consequences of the partial implementation of Mr Simpson's negligent instructions.

C. Issue 1: Material Facts

(1) Introduction

8. Queen's Road, Aldershot is a residential street whose terraced houses were built in about 1900. The house in question, Number 80, is located on the corner of Queen's Road and Church Street, which is a cul-de-sac. The house was built as a pair with Number 82 and, when originally built, Number 82 was the corner house. However, Number 82 was demolished in the 1960s. It was not known why or by whom Number 82 was demolished and the fact that it was demolished sometime between 1961 and 1971 was ascertained by comparing the 1961 Ordinance Survey map, which showed Number 82, with the 1971 Ordinance Survey map, which showed the site as being vacant. This demolition left an open narrow rectangular strip of land 18 feet wide and approximately 81 feet deep^[1] between the flank wall of Number 80 and the side of Church Street where it runs into Queen's Road. This strip is therefore bordered on its two long sides by the flank wall of Number 80 and by Church Street as it runs into Queen's Road and, on its two shorter sides by a small stretch of Queen's Road as it runs from Number 80 to the corner with Church Street and by the flank wall of Stable Cottage, the first property in Church Street. This strip is the area which Crowley had contracted to repave.
9. The strip on which Number 82 had been located was conveyed to Rushmoor as a vacant site in January 1975 and declared to be a public open space. It was then turned into an amenity area comprising a paved area with public benches and behind which a planter was constructed in which were planted a variety of trees, bushes and shrubs. There was no direct evidence as to who converted this site into an amenity area or as to when the necessary work was carried out. However, the paved area is open to the public and the site is a public open space which has never been formally dedicated as part of the highway^[2]. It is therefore an obvious inference that the amenity area, being both the planter and the adjacent stepped paved area, had been constructed by Rushmoor soon after it had acquired the vacant and private site in 1975 from its previous owner who was a private individual. There would have been no other reason for Rushmoor to acquire that vacant and otherwise redundant piece of land, for which it paid £1,000, other than to turn it into a public open space. Moreover, the site had not been turned into an amenity area at the time of the conveyance^[3] but this work had been completed by 1979 when Mr Sampla bought Number 80 since the amenity area with its planter was in place at that time. Thus, Rushmoor was the only person or body entitled to carry out this work.
10. For these reasons, I find that Rushmoor acquired the site when it was a vacant and private plot in order to turn it into a public open space. It achieved this objective by turning it into an amenity area comprising a stepped area made up by a planter on the upper step and a paved area on the lower step. This entire project was undertaken soon after Rushmoor acquired the site in 1975.
11. The front or lower half of the amenity area, running parallel with and adjacent to Church Street, was paved. Two bench seats were located in this lower area with their backs placed against the external side of the planter dwarf wall which was about 400mm high at the front end closest to the front of Number 80 and 600mm at the rear of Number 80 where it abutted the flank wall of Stable Cottage at the bottom of the site. The entire amenity area sloped relatively steeply in two directions. Firstly it sloped down from the front towards Stable Cottage at the rear of Number 80 and secondly it sloped down from the flank wall of Number 80 towards the inside edge of the pavement of Church Street.
12. Number 80 was three storeys in height at the front, reducing to two storeys in the middle and with a small single-storey lean-to shed at the rear. The house had five bedrooms. It was built of solid load bearing brick walls with timber suspended floors and a timber framed pitched roof. When Number 82 was demolished, Number 80 became a detached house. This was because Numbers 82 and 80 had originally been built as a pair of semi-detached houses. It was not obvious from an external inspection of the front or rear of Number 80 that it was not joined with Number 78. This only became clear when Number 80 was demolished prior to it being rebuilt after the collapse. The external wall adjoining the amenity area had originally been built as an internal party wall with Number 82 and, as a result, as with any internal party wall, it had significantly shallower foundations than either the external flank wall adjacent to Number 78 or any other load bearing flank wall of a similar construction.

(2) Factual matrix

13. The underlying problem. The amenity area provided two sources of nuisance and annoyance to the claimants. Firstly, the planter proved to be a source of damp penetration through the brickwork of Number 80 due to the influence of the vegetation growing, and the moisture accumulating, in the planter. Secondly, the amenity area attracted vandals, drug addicts and vagrants. Indeed, it had become known locally as "Dossers' Den". This resulted in rubbish and other detritus accumulating in and around the planter. The amenity area was also regularly used by fly tippers and by adolescents for intimate activities. Over the years, Mr Sampla had regularly complained to the council about these problems and had unsuccessfully requested Rushmoor on several occasions to cure the damp penetration problem into Number 80, to clear up the rubbish and to stop the site being used for antisocial purposes.
14. The Highways and Transport Services Department. After several previous unanswered complaints, Mr Sampla succeeded in persuading the Street Cleansing section of Rushmoor's Department of Highways and Transport Services to arrange to have the paved and planter areas cleared of rubbish and cleaned up on two occasions in 2000 as part of that section's street cleansing work.
15. This work did nothing to cure the underlying damp penetration problem or to provide a long term solution to the antisocial use made of the amenity area by dossers, drug addicts, fly tippers and local adolescents. Mr Sampla therefore, in May 2002, contacted his local councillor about the amenity area problems who, in turn, contacted Mr Pettitt, Rushmoor's Head of the Department of Highways and Transport Services. This department undertook all of Rushmoor's highways and public open spaces responsibilities. Within the Department, highways maintenance and cleansing was the responsibility of the Street Cleansing section managed by Mr Millington, the Highways Manager. He was directly responsible to Mr Pettitt and he was also Mr Simpson's manager. Mr Simpson was a Highways Officer with responsibility for supervising street cleansing and ancillary minor highways maintenance work carried out by the Street Cleansing section.
16. Mr Sampla's councillor's complaint was the sixth complaint to Rushmoor about the amenity area that had been instigated by Mr Sampla in the preceding five years. This complaint, as before, included a request that the amenity area should be cleared of the vegetation that was causing Number 80 damp penetration problems and that it should also be regularly cleaned up and rid of antisocial behaviour that it continued to attract. Mr Pettitt visited the site and then passed the councillor's complaint to Mr Simpson for action. As it happened, Mr Sampla had also separately re-established contact with Mr Simpson at about the same time and had asked Mr Simpson to resolve all the on-going problems associated with the amenity area.
17. Mr Pettitt took the initial decision as to what work was required to address Mr Sampla's complaints. He decided that the height of the plants and shrubs in the planter should be reduced and that the amenity area should be cleaned up. He therefore sent Mr Simpson a requisition which instructed him as follows:

"Resident complains of damp through his wall and foliage from planted area being a nuisance – can you please inspect the property and let me know if there is a problem and if the problem is on our land."

18. On receipt of this requisition, Mr Simpson visited the amenity area and decided that it was appropriate to extend the scope of work beyond that suggested by Mr Pettitt. He considered that, in order to stop the antisocial uses to which the site was being put, the planter should be removed and the entire area should then be paved. Mr Pettit stated in evidence that the proposed work, even though it involved site excavation, would not in his opinion have affected the foundations of Number 80. It was clear from his evidence that he had failed to consider that possibility when he inspected the site. Mr Pettitt then left Mr Simpson to sort out the details of the work that had been proposed by Mr Simpson and took no further part in the design or implementation of the proposed work.
19. Mr Simpson's solution had the effect of converting the amenity area from a public open space into an extension of the pavement at the junction of Queen's Road and Church Street. The proposed work was therefore changed in scope from cleansing and maintenance work into highway paving work that was to be carried out adjacent to Number 80 with its unduly shallow flank wall foundations. None of the three officials concerned with Mr Sampla's complaint appeared to notice or appreciate the significance of this major change in the scope of the proposed work
20. Mr Simpson discussed his proposal with Mr Millington who agreed with it and, having consulted Mr Pettitt, also agreed to include the work in the current highways rolling maintenance programme. All three officials regarded Mr Simpson's proposal as involving no more than a small low cost repaving exercise and as being similar to the highways cleansing and maintenance work that Mr Simpson usually undertook. In consequence, the work would be requisitioned as an informal maintenance contract by Mr Millington without the need for committee approval. It would therefore fall outside the standing orders requirements for larger contracts which would have involved the preparation of a site survey, drawings, a specification, a schedule of rates and tender documents, the use of formal tendering and committee approval procedures, a formal contract and the overall supervision of the work by Mr Simpson. In other words, the work was erroneously considered to be, using Rushmoor's shorthand, Direct Labour Organisation or DLO maintenance and cleansing work. Such work was invariably carried out in an informal manner that merely required a requisition and order signed by Mr Simpson and countersigned by Mr Pettit.
21. Mr Simpson. Mr Simpson was, in June 2002, close to retirement. He had started work at nineteen as a labourer in the highways maintenance field, had acquired a City and Guilds qualification in street works and had progressed to being an experienced highways inspector and highways cleansing contracts manager. He correctly described himself in evidence as an engineering technician.
22. Mr Simpson was therefore suitably qualified by experience to specify and manage a paving maintenance contract involving elements of highway cleansing. He had never had any training for, or experience of working with, buildings. It never occurred to him to seek the advice of a surveyor in the Rushmoor Building Control Department or to search out the documents in Rushmoor's possession that related to its acquisition of the amenity site. He clearly regarded such enquiries as being unnecessary since, in his inexperienced view, there was no possibility of the proposed work affecting any part of Number 80. Mr Simpson stated in evidence that it was never his practice to dig a trial pit or otherwise investigate the possible impact of proposed highway excavation work on adjacent buildings. He clearly assumed that the necessary excavation depth would not exceed 215mm anywhere on the site and that such a limited depth of excavation could not possibly have any adverse effects on the adjacent structure or its foundations.
23. Mr Crowley. Mr Simpson at that time regularly used a large engineering contractor called Quadron for the cleansing and maintenance work he arranged but he considered that Quadron was too large a contractor to undertake this very small contract. He therefore decided to invite Mr Crowley, as one of the small local contractors that he knew of, to meet him on site to discuss the proposed work with the intention of using him for that work. Mr Crowley had at that time only been in business on his own for a short period and he was then in his early thirties. He was a small unincorporated one-man contractor who only worked for local authorities. He traded as Crowley Civil Engineers and he employed three semi-skilled labourers. His sole formal qualification was an HNC in Civil Engineering. He had previously undertaken two jobs for Mr Simpson and had proved himself to be an efficient, low-cost highways maintenance and cleansing contractor. Mr Crowley was keen to again impress Mr Simpson since he wanted to attract a regular supply of local authority work from Rushmoor. He was in consequence particularly keen to carry out any proposed work precisely as required by Mr Simpson in order to attract a regular supply of such work.
24. Mr Simpson's suggested reliance on Mr Crowley. Mr Simpson stated in evidence that he considered that Mr Crowley was a qualified civil engineer and that, in consequence, he had relied on him to finalise the details of the work and to ensure that Number 80 would be protected from, and left undamaged by, the excavation work. For the same reason, he left him unsupervised on site to complete the work in a satisfactory manner. This view, it emerged in questioning, had been formed solely because Mr Simpson knew that Mr Crowley traded with the name "Crowley Civil Engineers".
25. I do not accept that this was Mr Simpson's view in 2002 of Mr Crowley or his expertise or that he relied on him in any way for any aspect of the design or detailing of the work. The reality was that Mr Simpson chose Mr Crowley because he had proved himself as a small one man business whose sole area of operations was highways cleansing and maintenance work. Mr Simpson would have seen Mr Crowley's estimates which were provided on his standard estimate form which held Mr Crowley out, perfectly correctly, as "Proprietor Mr T.D. Crowley" with no professional qualification being shown after his name and which described the business as being that of "civil engineers".
26. The description "civil engineers", when used to describe a contractor, has a different and less formal meaning to the description "Civil Engineer" when used by a qualified professional civil engineer. The former use of "civil engineers" merely describes the activities of a contractor whose business involves anything associated with external structures. This description does not connote anything about the size, turnover, experience or qualifications of that contractor and its personnel. The latter use of "Civil Engineer" describes a member of the Civil Engineering profession who has qualifications in civil engineering up to, at least, first degree level and who is invariably a member of the Chartered Institute of Civil Engineers..
27. Thus, both from his personal knowledge of Mr Crowley and from his knowledge of the difference between civil engineering contractors and a "Civil Engineer", Mr Simpson had, or should have had, no expectations about Mr Crowley other than that he had recently satisfactorily performed two minor paving maintenance and cleansing contracts for Rushmoor.
28. I therefore reject Mr Simpson's suggestion that he considered that he was contracting with an experienced and qualified civil engineer. In reality, Mr Simpson considered that he was contracting for a simple maintenance contract with a small maintenance contractor whom he considered to be a technically proficient small-scale highways maintenance contractor. He was not in any way relying on Mr Crowley for any aspect of the design or specification of structural or building work.

(3) The contract

29. Mr Simpson took Mr Crowley to the site on 6 June 2002. Mr Simpson also had a similar small job of approximately the same size that needed to be undertaken on Aldershot High Street. He decided to arrange for both these jobs to be done together as one contract and so he took Mr Crowley to visit that site at the same time. Given the proposed informal contract, Mr Simpson did not provide Mr Crowley with any documentation on which to base his estimate when he took him to these two sites.
30. Both jobs were described by Mr Simpson, when preparing the necessary internal requisition for the supply of these services, as involving:

"Grub up trees and lay block paving"

on both the Queen's Road/Church Street and the High Street/Court Road sites. At the site meeting on the amenity site, Mr Simpson explained to Mr Crowley what was required. Mr Simpson stated that the brick dwarf wall of the planter, the soil and shrubs it retained and the existing paving in front of the planter should all be removed. The whole site should then be excavated to a depth of 215mm, provided with an appropriate sub-base and sand and then paved with block paving using Rushmoor's standard block paving detail that Mr Crowley had previously used. This detail required the excavated base surface to be firm and level so as to receive one of the prescribed sub-base materials. It followed that additional excavation would need to be carried out if this was necessary in order to provide a suitable surface for the sub-base.

31. Mr Crowley's evidence was that he then asked Mr Simpson whether it was alright to excavate down to 215mm in areas adjacent to the flank wall of Number 80 given the potential damage that he assumed could occur to a dwelling house situated immediately adjacent to the proposed excavation work. Mr Crowley's evidence was that he was re-assured by Mr Simpson's reply which was to the effect that this was alright and that he, Mr Simpson, had no concerns with regard to excavation work being taken up to, or being undertaken down adjacent to, the external flank wall of Number 80. Mr Simpson denied that Mr Crowley ever asked him this question or that he had provided any answer in the same or similar terms to the answer that Mr Crowley said that he had given.
32. I accept Mr Crowley's evidence. I consider that Mr Simpson would have raised in discussion the question of how the site was to be excavated and whether it was safe to excavate up to the flank wall and that, if for some reason he had not raised this subject, Mr Crowley would have himself raised it with Mr Simpson. Given the background that I have already described, I am satisfied that Mr Simpson would have answered Mr Crowley's question in the way that Mr Crowley stated that he did. That suggested answer was in identical terms to Mr Simpson's previously formed view that the proposed work could be safely carried out and would not affect the structure of Number 80 in any way. It was suggested that the fact that Mr Crowley asked this question showed that he had concerns about the structural stability of Number 80 and was involved in the detailing of the proposed adjacent excavation work. I reject those suggestions. Mr Crowley was merely seeking re-assurance from Mr Simpson that Mr Simpson's instructions could be safely carried out and was entirely reliant on Mr Simpson's re-assuring reply.
33. Mr Crowley therefore accepted Mr Simpson's assurance and on his return home, devised a working method that could be used by Crowley which he then costed in the form of a lump sum estimate. This estimate was based on a working period of five days using his three labourers. He included in his estimate the cost of the hire of a small mechanical excavator and the cost of excavating across the site in successive vertical strips to a depth of 215mm and of acquiring and laying a sub-base of scalpings followed by a sand layer and then laying the block paving over the whole site. He proposed to sub-contract the actual laying of the block paving to a paving sub-contractor that he had previously used. For the amenity site work he submitted an estimate dated 7 June 2002 for £4,870.76. He coupled this with an estimate for the High Street work for £3,987.86. Both sums excluded VAT.
34. Mr Crowley' estimate stated:

"Thank you for your valued enquiry and further to our recent site visit we are pleased to submit the following quotation for your kind attention.

Court Road – Junction Paving

To excavate and clear trees, shrubs along with brickwork from site. Followed the supply and lay of block paving carried out in herringbone pattern and in accordance with your standard specifications.

Leaving the site tidy on completion.

For all plant, labour and materials.

For the sum of £4,840.76 (Exc. VAT)."

The estimate also included in a combined estimate the proposed High Street work.

35. For a contract of this small size, being less than £10,000, Rushmoor's internal procedures required an appropriate requisition to be issued which Mr Simpson issued on 18 June 2002 and Mr Millington then countersigned. The estimated cost was stated to be £8,828.62, being the combined estimate for both jobs. Mr Simpson then issued Crowley with an official Rushmoor order, also dated 18 June 2002, which was in these terms:

"Queens Road/Church Street/High Street/Court Road – Please grub up trees and lay block paving."

The order also stated that:

"Invoices quoting order number to be sent to the address at the top of the order. No goods to be supplied or work done except upon an official order. All goods must be carriage paid. E. & O.E. Terms: Payment 30 days from receipt of invoice (unless otherwise agreed)."

36. This document, and not Crowley's estimate, constituted the contractual offer to Crowley to undertake the proposed work. This was because Crowley's document was worded as an estimate or quotation and not as an offer. Moreover, Rushmoor's order was worded in different terms to the estimate and it stated on its face that the work had to be carried out on an official order. Therefore, the estimate was not intended to be, and could not in law have been, a contractual offer, this was provided by Rushmoor's official order.
37. Rushmoor's contractual offer was accepted by Crowley's conduct in starting work on the Queens Road site on Friday 28 June 2002. Since the estimate was not referred to in Rushmoor's order, it was not as a matter of law formally incorporated into the contract although, by necessary implication, the work to be carried out was the work instructed by Mr Simpson on site and as described in the estimate and the price was the lump sum provided by Crowley's estimate.
38. It had been agreed on site that the block paving work would conform to the "Footway Type 3 – concrete block paving" detail used by Mr Crowley in his previous dealings with Rushmoor. That detail provided the minimum depths for the sub-base material that would have to be laid under the block paving and sand layers. It also provided that the materials to be used were only to be materials chosen from those materials that were identified in clauses 603, 605 or 606, being clauses of the relevant British Standard. In this case, Mr Simpson chose and designated the use of scalpings, being one of those designated materials. Thus, Crowley was to lay a 100mm layer of scalpings and then a 50mm layer of sand. The clauses also specified that the excavated surface offered up for the sub-base scalpings should have had all soft spots, any vegetation roots and all other material capable of deteriorating or compacting removed and should be left in a firm and level state.
39. Mr Simpson's assurance that the site could be safely excavated right up to the external face of the flank wall of Number 80 had, and was intended to have, contractual significance. In its context, it amounted to an assurance that it was safe to excavate up to the flank wall to depths required for the paving work. Thus, Mr Crowley had no need to provide protective measures or to consider further whether protective measures were needed for the flank wall. Equally, he had no need to consider whether any intended method of excavation had to be adapted to safeguard the house and its foundations. It followed that if any additional excavation or protective work was needed, such work would fall within the E. & O. E. term in the contract since the work would have been necessitated by an error or an omission arising from Mr Simpson's design of the work and as a result of his unequivocal assurance given to Mr Crowley during their site inspection. If such work turned out to be required, it would have to be carried out but would have to be paid for by Rushmoor as additional work since it would have been necessitated by Mr Simpson's error or omission when specifying the work originally.
40. In the light of this matrix of facts and the terms of the contract that was entered into, it is possible to summarise the nature of the parties' respective obligations. In particular:

(1) The contract contained no implied terms as to fitness for purpose since Rushmoor was not relying on Crowley's skill and judgment in relation to any element of design, detailing or working method.

(2) Rushmoor had provided a warranty, which had contractual effect, that the specified planter removal and paving excavation work could be safely undertaken up to the external face of the flank wall of Number 80.

(3) Crowley had been asked to provide an estimate for, and had then accepted the offer of, a contract involving three simple work items: the demolition of the planter brick retaining wall and the removal of its contents; the excavation of the existing ground to a depth of 215mm across the site and the laying of block paving over a scalpings sub-base course and a sand topping level. The datum levels were to be taken from the levels at the inside edge of the adjacent pavement in Church Street.

(4) Crowley had to undertake any additional excavation that was necessary to provide a firm and suitable sub-base surface across the site so that the paving would lie across the site with a cross-fall of 2.5 such that it would abut and be level with the internal edge of the existing pavement

(5) Any other necessary work than the clearly specified work had to be carried out but would have to be paid for as an extra since it fell outside the work that was subject to the contractual lump sum. This was because of the effect of the E. & O. E. term in the contract whose effect was that any necessary work omitted from the contract by error or omission was work that had to be performed but which did not fall within the work covered by the lump sum. Thus, Crowley would be entitled to additional payment for carrying out such work. Any additional excavation to depths greater than 215mm, the breaking up of the concrete sections of the planter retaining wall and any necessary temporary or permanent supportive measures would all have fallen within the scope of the E & O E provisions of the contract since none of this work was expressly specified or detailed in the contract.

(6) Crowley was entitled to carry out the necessary excavations in any acceptable manner so long as this excavation method was carried out with reasonable standards of workmanship. Further, Crowley had no obligation to provide a method statement for this excavation work.

(4) Site and excavation details

41. Number 80's flank wall foundations. The external flank wall of Number 80, once it was exposed, was discovered to have been built on very shallow foundations. The brickwork was founded on a single brick corbel approximately 150mm deep which was sitting on the edge of blocks of concrete of about 200mm in depth so that only a narrow strip of the underside of each corbel was resting on an equivalently narrow strip of a concrete block which otherwise spilt outwards beyond the brickwork. It was obvious to those who inspected the exposed foundations or who looked at photographs of them that these concrete blocks had been placed in position long after Number 80 had been constructed and it was concluded, correctly as I find, that this concrete had been placed in position at the time that the foundations had been exposed as part of the construction of the planter in the 1970s.
42. Underlying ground. There was a layer of loose topsoil material below the concrete blocks which varied in depth from about 150mm below the front corner of the foundations, from about 300mm below the external redundant chimney flue in the middle of the foundations and from about 200mm at the rear corner of the foundations. Below this topsoil were layers of firm brown to orange brown silty sandy clay overlying firm orange brown, grey silty sandy clay. This overall layer of clays varied in depth from about 500mm below the front corner to about 130mm or less at the rear corner. Below this clay was a layer of moist fine sand. The topsoil was described by Mr Crowley as being very damp and soft, a condition that had been exacerbated by heavy rain on the day before and the day of the partial collapse. The loose and wet topsoil of variable depth and texture was not suitable, but the clay and moist fine sand sub-soil layers were suitable, as surfaces onto which the sub-base of scalpings could be placed.
43. Planter. The dwarf wall forming the planter varied in height above ground from about 400mm at the front to 600mm at the rear of the site. Its width of the planter was not identified in the evidence but it occupied about half the site and must, therefore, have been between 6 – 8ft or 2 – 3m wide. The wall was constructed parallel to the flank wall. As a result, the planter was constructed in an approximately rectangular shape with three sides formed by the dwarf wall and the fourth by the flank wall. The external face of the dwarf wall was constructed in brickwork. However, when the planter was demolished, Crowley discovered that this brickwork was merely the outer skin of the retaining wall and it only had a decorative purpose. The inner skin of the wall was constructed of concrete placed on a concrete slab foundation. The planter was full of topsoil which had been placed directly onto the underlying topsoil and clay layers. The planter soil was not, therefore, placed on top of paving. As constructed, the planter soil and the relatively loose pre-existing disturbed topsoil layers resting on the underlying clay merged so as to leave a depth of up to about 200mm of loose mixed material below the enclosure created by the dwarf wall that was unsuitable for providing a base for the scalpings..
44. The planter was constructed so as to provide substantial structural support for the flank wall and its foundations. The soil in the planter extended from between about 0mm and 100mm above the brick corbel to about 200mm below the concrete blocks. These blocks and the corbel above them provided the flank wall with totally inadequate support. The huge mass of soil within the planter was held in place by the concrete retaining wall and the slab supporting it and the planter structure and the soil retained within it fully supported and formed an integral part of the flank wall and its foundations and made up for the inadequate support of the foundations.
45. Theoretical minimum excavation depths relative to underside of flank wall foundations. In order to measure down 215mm to the stipulated depth across the site, Crowley was required to use as datum levels the finished paving levels at the inside edges of the pavement in Church Street. However, the slope of the site towards Stable Cottage was relatively steep such that the level of the underside of the flank wall foundations at the rear of the site was at least 200mm lower than at the front of the site. Moreover, the slope down across the site from the flank wall towards Church Street was also relatively steep. As a result, it was inevitable that the minimum depth of excavation 215mm down from the surface at the datum would have the result that the excavation adjacent to the foundations would extend to depths of up to 300mm below the excavated level at the flank wall and would therefore be at depths close to or at the flank wall that greatly exceed the stipulated 215mm.
46. Mr Vincent produced three representational cross-sections drawn across the front, middle and rear of the site. These had been drawn to show where the excavated surface would have had to have been located relative to the underside of the flank wall foundations assuming that the minimum possible excavation depth had been achieved using the prescribed datum levels. Mr Vincent presented these cross-sections as part of his evidence. There was no effective challenge to this evidence and I accept the cross-sections as an accurate representation of the relative levels of the excavated surface of the site and the underside of the concrete blocks forming the lower part of the flank wall foundations assuming that the minimum possible depth of excavation had been achieved. These cross-sections showed the excavated level to be at least 100mm below the foundations at the shallowest part of the site, 200mm in the middle part of the site and 300mm at the lowest part of the site. No account was taken when preparing these sections of the foundations below the redundant chimney flue where the excavated level would of necessity have extended much further below the foundations than that represented on these cross-sections.
47. Party Wall Actual minimum excavation depths relative to underside of flank wall foundations. When the planter had been demolished and its topsoil removed, Crowley discovered that the tree roots that remained were extensive and penetrated into the underlying loose topsoil and clay. This was because the loose topsoil within the planter extended down to at least the bottom of the shallow foundations of the dwarf wall and into the topsoil layer placed below the concrete mass foundations of Number 80.
48. The prescribed overall excavation depth of 215mm and the consequent theoretical exposure of variable depths below the flank wall foundations shown on Mr Vincent's representative cross-sections were minimum depths. In reality, the excavation had to be significantly deeper as a result of:

(1) The large step in the site and the site's relatively steeply sloping nature in both a downwards and a sideways direction;

(2) The removal of soft spots and the layer of poor quality topsoil below and adjacent to the flank wall foundations that was unsuitable to receive the prescribed sub-base of scalpings and sand topping;

(3) The need to grub out the tree roots at the many points where these had penetrated the existing topsoil and clay layers below the planter;

(4) The very shallow brick corbel foundations coupled with the variable depth of the concrete mass footings below this brickwork; and

(5) The need to provide the prescribed cross-fall of 2.5 in the paving surface down from the flank wall to the pavement in Church Street.

49. The overall result was that the actual depth of exposure below the flank wall foundations ranged from about 130mm to 400mm below the concrete mass footings which meant that the excavation depths ranged from 50mm to 350mm below the prescribed excavation depth of 215mm below the site surface. These assessed actual excavation depths were agreed by the three experts and are set out in the Experts' Joint Statement. The assessment was based on a representational drawing showing excavation depths prepared by RJP which was itself based on contemporaneous site-based observations by RJP's building surveyor. These depths were similar to the impressionistic recollections of the three eyewitness witnesses, Mr Crowley, Mr Ward and Mr Simpson.
50. In the middle of the flank wall, the excavation depth had to be taken to a depth of 600mm below the foundations. This additional exposure occurred along a short stretch around a redundant chimney flue, the remains of which were clearly visible on the flank wall at that location. In consequence, at this location, the foundations were even shallower than elsewhere along the flank wall. Moreover, the excavation also had to be appreciably deeper at this point than elsewhere along the flank wall due to localised unsuitable soil and base course material. The result of this localised reduction in the depth of foundations coupled with a greater depth of unsuitable material was that the foundations were exposed for a short stretch to a depth of at least 600mm below their underside.
51. Excavation. Crowley was not provided with any setting out levels or any prescribed method statement covering the excavation exercise. The method of construction required the creation by excavation of a suitable and level cross-site surface of existing material onto which would be placed a sub-base comprising a 100mm layer of scalpings below a 50mm layer of sand onto which the herringbone block paving would be laid. The finished surface had to be laid to a cross-fall of 2.5 across the site and a natural but even gradient down the site. Thus, the minimum depth of excavation would be 215mm but, as already found, this depth would inevitably be deeper to allow for the topography of the site and deeper still to accommodate the poor quality of the existing ground. The base course was to be as level as possible but any localised additionally excavated areas would be filled in by additional localised back-filling using the scalpings when this sub-base layer was placed in position. The finished cross-fall gradient would be achieved by laying the scalpings and then the sand to the appropriate gradient and by the correct setting of the block paving slabs when laid.
52. Once the site had been cleared of paving and the planter, it was set out using pins and a line across the site. A pin was placed 215mm into the ground at the Church Street side of the site and the other pins and line were set so as to provide an indication of the required excavated surface depth across the strip being excavated. These pins and line were moved down and across the site as required. The datum level was taken to be 215mm down from the inside edge of the adjacent pavement levels in Church Street. The excavation was undertaken using a mechanical excavator which moved vertically down the site from Queen's Road towards the flank wall of Stable Cottage at the bottom of the site. The excavation was therefore undertaken in strips with the first strip starting at the top outer edge at the junction with Queen's Road and moving down the site towards Stable Cottage. Each successive strip was excavated in turn and the strip closest to the flank wall was the last strip to be excavated.
53. Thus, it was only at a late stage in the excavation of the site as a whole that it was first appreciated that the excavation was extending below the flank wall foundations. This point was reached late on Thursday morning, 4 July 2002. The full extent of the exposure of the foundations was masked until a late stage by the outer face of the concrete blocks which appeared, until they had been fully exposed, to be adjacent overspill to, and not part of, the foundations. Until that point, the foundations appeared, and were assumed, to extend well below the concrete blocks. When full exposure of the foundations occurred, Mr Ward stuck a pin horizontally underneath the concrete blocks and discovered to his surprise that the pin, which was several metres in length, completely disappeared. Only then did he appreciate that the excavation had been taken down to levels well below the underside of the concrete blocks and that these blocks formed an integral part of the flank wall foundations. By that time, the excavation had been completed.
54. I find that the actual depths excavated on site were up to 300mm deeper than the prescribed minimum depth of 215mm below the site surface. This depth was required because of the sloping nature of the site and the poor quality of the excavated topsoil, particularly underneath the planter and adjacent to the flank wall which required an additional depth of excavation in order to achieve a satisfactory surface on which to place the scalpings. This essential additional excavation was required by the contract since it was needed to remove the band of loose unsuitable soil which extended to about 200mm below the bottom of the planter, localised soft spots and indentations left by the grubbing out of tree roots. The effect of this contractually appropriate depth of excavation was that the excavation exposed the foundations and a further band of material below the concrete blocks of about 130 – 400mm in depth. As an exception, the excavation exposed up to at least 600mm below the concrete blocks below the redundant chimney flue.
55. Excavation method. The method of working that I have found was used was not criticised by any of the experts. Had Mr Crowley been informed that he should take particular care when excavating adjacent to the foundations, or had he been provided with the results of trial pits dug adjacent to the foundations, a different method of excavating in that area would have been called for which would have involved protective measures which Rushmoor would have had to have specified in advance. Crowley was entitled to proceed on the basis that it could adopt, without any prior investigation, whatever excavation measures it chose that were suitable for excavating a relatively small sloping urban site. The evidence suggests that Crowley carried out the excavation exercise with reasonable skill and care and that no over-excavation occurred. In other words, Crowley undertook no excavation in excess of what was required to conform to the topography of the site and the conditions on site and so as to provide an appropriate excavated surface which was at least 215mm deep or, if deeper, only deeper to the extent reasonably necessary to comply with the contract. Given the small area being excavated, the entire excavation exercise only took about four hours and it was started and completed during the morning of 4 July 2002.
56. The finished excavation provided a relatively level firm excavated base across the site whose depth was never less than 215mm below datum and was only greater than 215mm where necessary. Crowley then placed the scalpings sub-base material onto this excavated surface. When the partial collapse occurred, Crowley had placed scalpings at variable depths between 100mm and 200mm so as to provide the minimum specified depth of scalpings and any additional localised depth needed to bring the excavated surface up to the level where 50mm of sand and the block paving could then be placed so as to align with the adjacent pavement edge to the specified gradient.
57. Conclusion. I find that the excavation was carried out with appropriate standards of workmanship and with the use of an appropriate working method, that no over-excavation occurred and that the excavated depths that were achieved at all points across the site conformed to Crowley's contractual obligations. I also find that the inevitable consequences of excavating in accordance with the contract obligations were that:

(1) The excavation of the existing site resulted in excavating across the site to varying depths below 215mm. At the edge of the site adjacent to the flank wall, these depths ranged between approximately 50mm and 300mm below that excavation depth of 215mm.

(2) This excavation inevitably exposed the foundations of the flank wall along its entire length and the excavation also inevitably extended below the underside of those foundations by varying depths ranging between approximately 130mm and 400mm below their underside save for the length below the redundant chimney flue where the excavation inevitably extended to a depth of up to approximately 600mm below their underside.

(3) The excavation as carried out by Crowley was carried out with reasonable standards of workmanship, involved no over-excavation and, nonetheless, excavated, and could not have avoided excavating, to the depths below datum levels set out in (1) above which inevitably produced excavation depths below the concrete blocks that are set out in (2) above.

58. I base these findings on the evidence of Mr Crowley and Mr Ward who described the setting out method that was used and the method of excavation that was adopted. No other evidence was adduced that suggested that this working method was applied inappropriately, that the standards of workmanship were other than reasonable or that the excavation went deeper than the reasonably practicable minimum depth at any point on the site. Furthermore, my findings are supported by evidence from the various witnesses' impressions of the finished excavation levels as seen on site on 4 and 5 July 2002. They are also supported by the evidence of the experts who, by interpolation from RJP's survey work, Mr Vincent's desk exercise and contemporaneous photographs reached conclusions that showed that the minimum excavated depths that could be achieved by Crowley were similar to the depths that Crowley actually achieved

(5) Course of the work

59. Phase 1 – Site set up and planter removal. Mr Crowley visited the site on a daily basis. The first phase of the work started on Friday 29 June 2002 when Mr Ward, the site foreman and Mr Crowley's other two employees, Mr Ansell, who operated the mini-excavator, and Mr Allright arrived on site. On 29 June 2002, the three men cut down and removed the existing shrubs and bushes to ground level, shredded that vegetation and removed it from the site and then removed the root stumps so far as possible. On Monday 1 July 2002 and Tuesday 2 July 2002, the coping stones on the dwarf walls, the paving slabs and the two bench seats were removed and the dwarf wall demolition was started. On Wednesday 3 July 2002, the dwarf wall demolition continued and was completed and the hardcore below the removed paving was broken up and removed. The excavation work, including the removal of the planter soil, was not started on Wednesday 3 July 2002. At one point in his oral evidence, Mr Ward suggested that he had telephoned Mr Crowley on Wednesday evening and during his call had referred to the exposed foundations of the flank wall. However, Mr Crowley had no recollection of such a discussion on the Wednesday and it is not possible for such a discussion to have taken place since no excavation work had been started by the time work stopped for the day.
60. Phase 2 - 4 July 2002. The excavation work including the transportation of the excavated material, was started and, by about 1.00 pm the excavation was completed. It was only after the excavation had been completed that it became clear to Mr Ward that the underside of the foundations had been exposed and that the excavation extended well below the foundations. Mr Ward's evidence was to the effect that it would not have been possible to discover that the excavation was exposing, or would inevitably expose, the foundations and then extend below them any earlier than when this discovery was made. He explained that prior to the excavation of the last strip, no part of the foundations was exposed and once the excavation of the last strip adjacent to the flank wall had been started, it seemed that the exposed concrete was not part of the foundations but was external overspill. Thus, even at that stage, there was nothing to be concerned about. The final strip was excavated very rapidly and as soon as it had been completed, it was then obvious that the foundations and a significant layer below the foundations had been exposed. Mr Ward immediately asked Mr Ansell to telephone Mr Crowley to get him to come to site urgently. Mr Crowley arrived soon afterwards, rapidly took stock of the situation and then telephoned Mr Simpson and asked him to come to site urgently. Mr Simpson arrived soon afterwards by which time it was the early afternoon.
61. Mr Simpson's instructions. There were very significant differences between the evidence of Mr Crowley and Mr Ward on the one hand and that of Mr Simpson on the other as to what Mr Simpson said to Mr Crowley and instructed him to do.
62. Mr Simpson stated in evidence that as soon as he had arrived on site and had inspected the exposed foundations, he was aghast at what he saw. However, he did not appear to be concerned or agitated to either Mr Crowley or Mr Ward and his actions on 4 July 2002 were not those of someone who was concerned about the situation or who was trying to instigate urgent action to address a dangerous situation. I do not accept Mr Simpson's evidence as to his state of mind. Mr Simpson was and remained unaware of, or turned a blind eye to, the fact that the foundations, the flank wall and the whole of Number 80 had all been imperilled and undermined by the excavation that had just taken place.
63. It is clear, however, that as soon as Mr Simpson had inspected the excavation, he assumed that Crowley had over-excavated the site and that Crowley could have stopped, but had failed to stop, the excavation below a point 215mm below the surface of the site. Even in his oral evidence, he appeared to retain his misconception that the foundations were constructed to a normal depth for a load bearing flank wall and that it would have been possible for Crowley to have terminated the excavation only 215mm into the existing soil across the entire site.
64. Having inspected the exposed foundations, Mr Simpson then discussed the situation with Mr Crowley and gave him oral instructions as to how to proceed. Mr Crowley stated that the discussion started with him telling Mr Simpson that he was unhappy with the soft ground conditions and with the fact that the excavation had exposed the footings. Mr Simpson, however, appeared unconcerned with the situation. He assured Mr Crowley that "foundations are my forte" and that he had had twenty to twenty five years' experience of underpinning. Mr Simpson also told Mr Crowley that he was sure that underpinning was not required in the situation that had arisen and reiterated that he was able to speak with such confidence because of his long experience with underpinning that went back at least twenty five years. Mr Crowley contended that Mr Simpson then gave Mr Crowley instructions as to what was to be done. These were not conveyed with any sense of urgency. Remarkably, Mr Simpson never recorded these instructions in writing at the time or subsequently and no written instructions were ever issued to Crowley. The only written evidence produced by Mr Simpson of his instructions was to be found in a note that Mr Simpson left at Number 80 on leaving the site at the conclusion of this discussion.
65. Mr Crowley's evidence was that Mr Simpson instructed him to dig a trench 200mm deep parallel to, and 200mm away from, the flank wall. The trench was to run the entire length of the flank wall. A single skin brick wall was then to be built out of the trench to the height of the existing footings. At the same time, ordinary concrete was to be laid as a slab in the space between this trench and the existing footings of the flank wall foundations. Mr Crowley then informed Mr Simpson of his proposed timescale for this work. The trench would be dug on the following day, the necessary shuttering and concrete pour would take place on Sunday 7 July 2002 and the brick wall would be constructed on Monday 8 July 2002. Mr Simpson appeared to accept that proposed programme of work without any comment or disagreement. Mr Crowley explained in his evidence that he had been satisfied by Mr Simpson's re-assuring manner that his proposed method of supporting the foundations was an acceptable and appropriate way to address the apparent danger caused by the over-exposed foundations. Mr Ward, who said that he had listened to the whole of this exchange, confirmed Mr Crowley's evidence as to what Mr Simpson had stated and instructed.
66. Mr Simpson denied almost all of Mr Crowley's evidence of the discussion. In particular he denied that he had referred to his extensive experience of underpinning or to underpinning being his forte. He attempted to reinforce this denial by stating that he had no idea, even when giving evidence, of what the word forte meant. Mr Simpson also denied that the instructions he had given to Mr Crowley were anything like the instructions Mr Crowley had stated that Mr Simpson had given him.
67. Mr Simpson's evidence in court and in his witness statement settled in May 2008 was to the effect that he had instructed Mr Crowley that quick setting lean mix concrete should be placed underneath the exposed footings and up to their top. The concrete should be contained in steel shuttering. This should be placed one metre away from the flank wall along its entire length and the concrete should be placed in the gap between the shuttering and the external face of the footings. Once the concrete had set, a brick wall to a height of 500mm built with a double skin of ordinary house bricks should then be built against the outer face of the concrete.
68. This evidence was inconsistent with Mr Simpson's contemporaneous behaviour nearly six years previously. At the time of the collapse, Mr Simpson had acted as if he had given instructions to Mr Crowley similar in terms to those that Mr Crowley had stated that he had received from Mr Simpson. This inconsistency was clearly demonstrated by the note that Mr Simpson left Mr Sampla immediately after his discussion with Mr Crowley on site on 4 July 2002 and by the instructions or statement that he must have given to Rushmoor's solicitor a few weeks later.
69. As to the note, following the conversation between Mr Simpson and Mr Crowley, Mr Simpson went to call on the claimants but found that no-one was in. Mr Simpson then wrote out a note addressed to Mr Sampla and pushed it through the letter box of Number 80. The original note was not available to either Rushmoor or Crowley but its contents had been set out verbatim in the claimants' particulars of claim whose authenticity had been verified by Mr Sampla. In this pleading, it is stated that the note read as follows:

"Please ring me with reference to work at the side of your house. I would like to build a small retaining wall to cover your footings and would like your agreement to the finish."

This note appeared to be proposing the construction of a dwarf wall close to the flank wall. Such a wall would have required a trench to have been dug and this proposed method of construction would have been similar to that that Mr Simpson had just, according to Mr Crowley, instructed Mr Crowley to undertake.

70. As to his apparent instructions or statement to Rushmoor's solicitor, it is necessary to consider what that solicitor had stated in a response dated 14 November 2002 sent as a reply to the claimants' letter before action. The response, given its terms, could only have been based on instructions or a statement emanating from Mr Simpson. The solicitor's letter stated:

"Crowleys were not instructed to continue to dig below the foundation. Instead they were immediately instructed to take remedial action by constructing a footing and retaining wall 500mm away from the building and backfill with mass concrete to the top of the existing footings."

Rushmoor' solicitor was therefore suggesting that Mr Simpson had given Mr Crowley very similar instructions to the instructions that Mr Crowley had stated he had received.

71. It can be seen, therefore, that both the note written by Mr Simpson immediately after he had given instructions to Mr Crowley and the instructions or statement that he must have given to Rushmoor's solicitor some five months later support and confirm Mr Crowley's version of the instructions that he stated that he had been given by Mr Simpson. This is very significant since the remedial scheme that Mr Crowley stated that Mr Simpson had instructed on 4 July 2002 was considered by the experts to be both ineffective and one that enhanced the danger of collapse. However, the remedial scheme that Mr Simpson had stated at the trial that he had instructed Mr Crowley to provide was one that was very different to Mr Crowley's version but was similar to the scheme that the experts in their evidence stated should have been adopted as a matter of urgency. It was, according to the experts, a scheme which could well have avoided the collapse if it had been put in place within twenty four hours of Mr Simpson's visit to the site.
72. Mr Simpson was unable to give a satisfactory explanation for these very significant inconsistencies between his contemporaneous behaviour and his subsequent evidence in court. Moreover, he could not explain how he came to write the note that he pushed through Mr Sampla's letter box in the terms that he used and he also stated, unconvincingly, that he could not remember giving instructions or a statement to Rushmoor's solicitor. Moreover, Mr Simpson could not explain how, six years after both writing the note and giving instructions, he had given such a significantly different account of his instructions to Mr Crowley in his witness statement and in his oral evidence. Finally, and particularly tellingly, Mr Simpson could not explain why he had not remonstrated with Mr Crowley immediately after the collapse, particularly when he met Mr Crowley on site the day after the partial collapse and inspected the damage and could see that Mr Crowley had departed so blatantly from the instructions that he contended that he had given him^[4]. All these features of Mr Simpson's evidence suggest that Mr Simpson had given Mr Crowley the instructions that Mr Crowley has stated that he had received and that his evidence in court had been contrived in an attempt to exculpate himself.
73. Mr Darling QC, counsel for Rushmoor, sought to find support for Mr Simpson's evidence from Mr Ward's evidence and, at the same time, attempted to downplay the way that Mr Ward's evidence appeared to corroborate Mr Crowley's evidence. Mr Darling submitted that Mr Ward's evidence was wholly confused. Initially in his evidence, Mr Ward had stated that shuttering was instructed by Mr Simpson. He then, according to Mr Darling, changed his evidence when it was put to him in cross-examination that this evidence supported Mr Simpson's evidence, then only in witness statement form, and did not support and indeed undermined Mr Crowley's evidence, than also in witness statement form. Mr Ward then appeared, in what was suggested to be his changed evidence, to state that a trench was instructed into which concrete footings would be poured. Mr Darling submitted that Mr Ward's first version should be preferred and that the effect of that first version was that Mr Ward had heard Mr Simpson giving Mr Crowley instructions to backfill the ground adjacent to the flank wall with concrete and that he had not heard Mr Simpson instructing the construction of a dwarf wall or the digging of a trench. Mr Darling therefore relied on Mr Ward's evidence as providing powerful support for Mr Simpson's evidence of the instructions that he gave Mr Crowley.
74. Mr Darling had arranged for Mr Ward's evidence to be transcribed. A careful reading of this transcript shows that Mr Ward's evidence was somewhat confused in places but that its general line throughout supported Mr Crowley's version of the instructions that he had been given by Mr Simpson. Mr Ward's reference in his evidence to the use of shuttering is ambiguous and could, taken on its own, support either version of the instructions since both versions of the proposed supportive scheme would have required the use of shuttering. Taken as a whole, Mr Ward's evidence does not suggest at any stage that the nature of the instructed supportive scheme was as contended for by Mr Simpson and, indeed, his evidence suggests to the contrary, namely that these instructions were similar in content to the version contended for by Mr Crowley. Mr Ward's evidence, therefore, corroborates rather than undermines Mr Crowley's evidence as to Mr Simpson's instructions.
75. In the light of all this evidence, I have no difficulty in finding that Mr Crowley's and Mr Ward's version of the instructions that Mr Crowley was given by Mr Simpson is correct. In making this finding, I have taken account of the context in which the instructions were given to Mr Crowley. Crowley was, as I have already found, undertaking what both parties considered to be a small informal contract which only involved maintenance and cleansing work that had been devised by, and was entirely under the control of, Mr Simpson. Mr Crowley looked to Mr Simpson for all decisions, particularly those affecting the adjoining Number 80. He relied, as he was entitled to, on Mr Simpson's pre-contract site statement that it was safe to excavate up to the flank wall of Number 80. Moreover, he was keen to impress Mr Simpson and to show that he was able to work satisfactorily for Rushmoor since he wanted many more contracts from Rushmoor. He had also called Mr Simpson to site once the foundations had been exposed in order to obtain Mr Simpson's instructions as to how to proceed. For all these reasons, Mr Crowley had every incentive to do exactly what Mr Simpson instructed him to do and had no incentive to depart from any instructions he was given by Mr Simpson.
76. If Mr Simpson's version of what he instructed Mr Crowley to do is correct, Mr Crowley would have had to have deliberately and for no apparent reason immediately proceeded to disobey the instructions that Mr Simpson had just given him. Such a flagrant departure from those instructions could not have occurred by mistake and such deliberate misbehaviour would have been inexplicable, particularly given the factual background that I have just summarised and also given the real likelihood of this disobedience being discovered. Moreover, I prefer the evidence of Mr Simpson's contemporaneous thoughts as shown by the contents of his note to Mr Sampla and the instructions or statement that he must have given to Rushmoor's solicitor rather than his apparently tailored evidence provided six years later. These earlier thoughts and actions, coupled with Mr Ward's evidence, all corroborate Mr Crowley's evidence which is, moreover, inherently more probable than Mr Simpson's evidence. I therefore accept Mr Crowley's evidence and reject Mr Simpson's evidence.
77. Phase 3 - 5 July 2002. The laying of the scalpings had started on 4 July 2002 and this work, and the digging of a trench 200mm deep and 200mm away from the flank wall, took up the whole of 5 July 2002. Crowley dug this trench in compliance with what Mr Crowley had understood to have been Mr Simpson's instructions. It rained very heavily throughout most of 5 July 2002 and this made the ground below the flank wall foundations very wet and, during the afternoon, earth was observed to be being washed out from under these foundations. Mr Crowley had intended to place the shuttering for the concrete work and to pour the concrete on Sunday 7 July 2002 and to arrange for a bricklayer to build the instructed brick dwarf wall on Monday 8 July 2002. However, during the evening of Friday 5 July 2002, cracks were seen to be visibly widening within Number 80 and, at about 22.00 hours, the back wall of the rear single-storey addition and part of the laundry room collapsed. The majority of the flank wall remained in place but could be seen to have significantly rotated.
78. Phase 4 – 6 July 2002 and thereafter. Mr Crowley was informed during the morning of the following day, Saturday 6 July 2002, by telephone that the partial collapse had occurred. The call was made by someone unknown to him and, from the evidence of Mr Pettitt, it would seem that the caller was Mr Saker, who was Rushmoor's Chief Building Control Officer and who had assumed responsibility for putting in place arrangements to make Number 80 safe. Mr Crowley visited the site and, from the road, saw what had happened. He felt so bad about the collapse that he did not attempt to contact the claimants who he had been informed by Mr Saker were unharmed. By the time he visited the site, contractors had already arrived and were demolishing much of Number 80 in order to make it safe for the claimants to remove such of their possessions as could be removed.
79. Later in the morning, Mr Crowley was telephoned by Mr Simpson. According to Mr Crowley, Mr Simpson immediately asked him if he was aware of the problem and whether he had visited the site. Mr Crowley answered both questions affirmatively. Mr Simpson then asked whether he had spoken to anyone and Mr Crowley answered "no". Mr Simpson then told Mr Crowley that he was not to say anything to anybody at this stage. Mr Crowley informed him in reply: "I told you it needed underpinning" and, according to Mr Crowley, Mr Simpson replied: "I felt it wasn't needed." Mr Simpson asked Mr Crowley to meet him on site as soon as possible and they met and inspected the damage. Mr Crowley stated that Mr Simpson appeared shocked and did not communicate with him other than to say that Mr Crowley should not say anything at this stage. Mr Simpson accepted that he had made the telephone call to Mr Crowley and had met him on site but denied instructing Mr Crowley not to say anything at this stage on either occasion and also denied stating that he felt that underpinning was not needed.
80. Mr Pettitt also visited the site in the afternoon of 6 July 2002. He had not been involved in the work since his initial inspection in May. He inspected the damage but did not speak to anyone and was unable to recollect taking any further action or speaking to anyone about the partial collapse following that visit.
81. Following these visits to site, Rushmoor does not appear to have made any further investigations into the partial collapse. On instructions, Mr Darling informed the court that Rushmoor's solicitor had made a careful inspection of all relevant internal documentation and full enquiries of all relevant officials. These confirmed that Rushmoor had made no internal investigations or report of the incident and had passed the whole incident and its consequences over to its insurers and the solicitors instructed by those insurers to deal with it. Mr Simpson did not refer to this incident again to Mr Crowley. He retired from Rushmoor in May 2003 when Hampshire County Council took over Rushmoor's highways maintenance work. Mr Crowley stated that he had, much more recently, received further work from Rushmoor.
82. I accept Mr Crowley's version of his communications from and with Mr Simpson on Saturday 6 July 2002. Mr Simpson was not an impressive witness and he could not explain why, given his version of his instructions, his telephone call to Mr Crowley his visit to site visit when he met Mr Crowley, he had said nothing to Mr Crowley about Crowley's over-excavation nor, as I have already found, why he did not remonstrate with him about his disobedience in relation to the implementation of his instructions for implementing supportive measures. I am satisfied that Mr Simpson's comment about underpinning and his insistence that Mr Crowley should not say anything to anyone amounted, in context, to admissions that he considered himself to have been responsible for the partial collapse and for the decision not to underpin the foundations on 4 July 2002 and, instead, to dig the shallow trench in preparation for the construction of a dwarf wall. This conclusion is reinforced by Rushmoor's subsequent failure to take any steps even to report the incident to any committee of the Council. It is particularly telling that Rushmoor appears to have taken no further steps internally to investigate the collapse and did not communicate in any way with Mr Crowley about it. This also suggests that Rushmoor internally accepted that it was responsible, or primarily responsible, for the partial collapse.

D. Issue 2: Expert Evidence

(1) Pre-contract survey and documents

83. It was clear from the expert evidence that anyone with appropriate training and experience undertaking a competent building survey could see at a glance that the site was problematic. The site abutted against the flank wall of a dwelling house and the excavations were to be taken up to that flank wall. The site itself was sloping in two directions, down from the flank wall and down from front to rear and it was also steeply stepped with a filled planter located on the upper step which was built up to and against the flank wall. The planter itself, given its height and the fact that it ran along the entire length of the flank wall, was obviously constructed so as to provide significant support to the flank wall and its foundations. A house had previously occupied the amenity site and this missing house had clearly been built so as to abut Number 80. A cursory inspection of the exposed flank wall of Number 80 would have shown that this exposed flank wall had been built as an internal party wall and not as an external structural wall. This was particularly evident given the existence of a redundant chimney flue running up the flank wall from what must have been the fireplace of the demolished property.
84. A competent inspection of the site would therefore have concluded that the foundations of this flank wall would have been both shallow and significantly shallower than those constructed for an external flank wall. Thus, instead of foundations constructed with at least six courses of bricks to a depth of 375mm to 450mm into the unexcavated ground, it was to be expected that, subject to local ground conditions, the foundations were very significantly shallower than this depth and were likely to be exposed by the proposed excavation.
85. All these factors, whether taken individually or, more significantly, taken together, pointed to the need for Mr Simpson to have arranged for two, or probably three, trial pits to be dug at the front, middle and rear portions of the flank wall so as to ascertain the depth, nature and condition of the foundations, the relationship between the bottom of the proposed excavation and the underside of those foundations and the nature of the underlying subsoil. These trial pits would also have identified how and to what extent the planter provided structural support to the flank wall.
86. Given the difficult and uncertain topography of the site, a series of cross-sections should also have been prepared which showed the finished excavation levels to be achieved by the excavation exercise and which also showed the depth and location of the adjacent foundations relative to the finished excavation levels.
87. Rushmoor should have undertaken the trial pit and surveying exercises and have included the results of both in the documentation incorporated into the contract. Furthermore, these exercises would have shown that the foundations of the flank wall were particularly shallow, that the concrete blocks were subsequent additions and had been constructed in a way that provided only minimal additional support for the flank wall, that the site once excavated would leave the entire depth of foundations exposed with a further depth of up to 200mm being exposed as well, that below the chimney flue the foundations were particularly shallow and would be exposed to an even greater extent than the other lengths of the flank wall and that the planter was constructed so as to provide significant structural support to the flank wall and its foundations.
88. In consequence, Rushmoor should have designed additional permanent support for the flank wall that should have been installed before the planter had been removed. This support should have been in the form of a concrete slab placed against the flank wall that extended away from the wall horizontally for about one metre and extended upwards to a point immediately above the top of the exposed foundations. Alternatively, the work should have been designed so as to leave an unexcavated buffer zone of about one metre in width extending horizontally outwards from the flank wall. The contract specification should have specified how the wall's supporting and protective measures should be constructed and how the excavation should have been undertaken. Any supporting concrete should have been placed in position as the first piece of work and should have been placed in a series of small sections. Once this work had been completed, the planter should then have been removed and the site should then have been excavated in a sequence and by the use of a method which caused minimum disturbance to the concrete foundations and flank wall. All these measures should have been specified in advance of work starting and should have been included in contract documents. The notification procedures required by the Party Wall Party Wall Act should also have been followed.

(2) Excavation

89. Two of the experts agreed that Crowley should have ceased excavating when the top of the concrete foundations was reached. The third expert considered that the cessation of excavation should have occurred when Crowley reached the underside of the concrete blocks. Crowley should then have determined the depth of concrete by carefully undertaking one or two small investigative excavations. On finding that the concrete foundation was shallower than the intended depth of excavation, Crowley should have stopped work and obtained further instructions from Rushmoor.
90. The apparent difference of opinion between the experts as to when Crowley should have stopped work has no practical significance. Crowley undertook the last strip of excavation, being the strip nearest to the foundations, as the last element of the excavation exercise. The foundations had not been uncovered until that strip was started and the entire strip could only have taken a matter of minutes to carry out. Thus, Crowley could not reasonably have ascertained that the excavation was uncovering either the top or the underside of the concrete foundations let alone a significant additional depth below the foundations until it had completed, or virtually completed, the entire excavation exercise.

(3) Emergency Action

91. All three experts agreed that concrete should have been placed alongside the flank wall to provide support to the undermined foundations as soon as it was discovered that the excavation was inevitably going to expose the foundations. The concrete should have been placed alongside the entire length of the wall to a depth covering the exposed foundations and extending out horizontally for a distance of at lease one metre from the flank wall. This concrete should have been put in place before work ceased on 4 July 2002 and, if it had been, it is likely that the collapse would not have occurred. Had the concrete not been put in place until 5 July 2002, it was considered that it would still have been likely, but less so, that the collapse would not have occurred.
92. The experts considered that the action taken by Crowley in digging a trench alongside and close to the flank wall had had the effect of further undermining the foundations. Moreover, they were very critical of the lack of urgency and the proposed postponement of any concreting work until Sunday 7 July 2002. The experts also considered that the supportive scheme being implemented by Crowley would have had much less chance of preventing the collapse than the scheme that they recommended should have been implemented, even if the concrete had been put in place on 4 or 5 July 2002. I conclude that, on the balance of probabilities, Mr Simpson's proposed method of supporting the flank wall, even if the concrete had been put in place by the end of the working day on 5 July 2002, would not have avoided the partial collapse that occurred.

(4) Cause of partial collapse

93. Foundations constructed of brick footings placed on concrete provide support to a flank wall by virtue of the support provided to the sides and the base of the foundations. If the side support is excavated and removed, the stability of the foundations is considerably reduced. The soil, particularly towards the rear of Number 80, was sandy and relatively non-cohesive in nature. This further reduced the stability of the foundations once their side support had been removed. Once the foundations had been exposed, such cohesion as the soil retained would have been rapidly lost. The sandier the soil, the more rapid would have been this loss of cohesion. The collapse therefore occurred because the foundations were shallow at the best of times but the reduced support that they provided was largely removed by the removal of the planter and the subsequent excavation of the underlying soil and it totally disappeared along the section of the flank wall that collapsed when the adjacent soil rapidly lost its remaining cohesion given that the underlying soil was sandy at that point.

E. Issue 3: Crowley and Rushmoor's Breaches of Duty

(1) Introduction

94. Liability to pay contribution is based on it being shown that the claiming party and the party against whom the contribution claim is being made are both parties from whom the person suffering damage is entitled to recover compensation for damage whatever the legal basis of each party's liability might be, whether tort, breach of contract, breach of trust or otherwise. The apportionment of each party's contribution towards the overall recoverable damage is to be based on what is just and equitable having regard to the extent of each party's responsibility for that damage.
95. It is therefore necessary to identify the bases of liability of both Crowley and Rushmoor to the claimants and the causes of the claimants' damage. Based on those findings, it is finally necessary to ascertain what can justly and equitably be considered to be the respective responsibilities of Crowley and Rushmoor for that damage expressed in percentage or arithmetical terms.

(2) Party Wall etc Act 1996.

96. Party wall legislation enabling buildings and structures on the junction between two properties to be constructed, repaired and demolished where the building owner cannot obtain reasonable consents from an adjoining owner, was first enacted for properties located in London to assist in the rebuilding of the City of London following the Great Fire in 1666. This initial party wall and building legislation led to a succession of London Building Acts. It was only in 1996 that this legislation was extended to all parts of England and Wales by the Party Wall etc Act 1996 ("the Party Wall Act") which had the effect of turning the regime that had operated in London for so long into a country-wide regime.
97. The current legislation allows an adjoining owner to undertake work which could otherwise be prevented by an adjoining owner because the work would involve work to, or working on, the adjoining owner's property if that property situated on the boundary between the two properties and adjoins the property on which the proposed work is to be undertaken. The legislation therefore enables work to be carried out which would otherwise amount to a trespass. The legislation also provides a means of agreeing what work should be carried out by providing a mechanism whereby the proposed work can be authorised and approved by surveyors appointed by the parties as being reasonable and safe. The legislation also seeks to provide a means of ensuring that work carried out on an adjoining owner's land will not damage adjoining property located on the junction between the two properties. Any dispute about any such work is resolved by the appointed surveyors acting as statutory arbitrators and the Party Wall Act confers such surveyors with jurisdiction to award compensation and to settle the details of any work covered by the Party Wall Act.
98. In relation to Number 80 and the adjoining planter on Rushmoor's adjoining amenity site, the Party Wall Act was engaged for two separate but interlinked reasons. The first reason for the Party Wall Act to be engaged was because:

"… a building owner [i.e. Rushmoor as "an owner of land desirous of exercising rights under this Party Wall Act"] proposes to excavate .. within three metres measured horizontally from … a building [Number 80] of an adjoining owner [Mr Sampla] and [a] …part of the proposed excavation will within those three metres extend to a lower level than the level of the bottom of the foundations of [Number 80]." (see sections 6(1)(a) and 6(1)(b) and the definition of "building owner" in section 20 of the Party Wall Act).

99. The second reason for the Party Wall Act to be engaged was because the planter was attached to the flank wall and provided that wall and its foundations with direct structural support along its entire length. It was therefore a foundation covered by the Party Wall Act by virtue of the definition of "foundation" in section 20 which provides that the foundations of the flank wall include:

"… the artificially formed support resting on solid ground on which the wall rests".

100. The flank wall and the planter therefore constituted both a party wall and a party structure as defined in section 20. In consequence, Rushmoor's decision to demolish the planter and replace it with paving engaged the Party Wall Act because:

"… lands of different owners adjoin and at the line of junction the said lands are built on or a boundary wall, being … the external wall of a building, has been erected." (sections 2(1) and 2(k) of the Party Wall Act).

101. The Party Wall Act was, therefore, engaged because Rushmoor proposed to demolish the planter foundations and pave the site in its ownership and because that work necessitated excavating within three metres of the flank wall of Number 80 to levels below the flank wall's foundations. The Party Wall Act required Rushmoor to serve on Mr Sampla a notice indicating its proposals and stating how it was proposing to underpin, strengthen or safeguard the foundations of the flank wall with accompanying plans and sections showing the site and depth of excavation (see sections 2(1), 3 and 6(5) of the Party Wall Act). Any dispute as to these proposals had to be settled by the arbitration provisions of the Party Wall Act by a surveyor or surveyors appointed by the two adjoining owners. These provisions of the Party Wall Act are mandatory and it is no answer to the non-service of the requisite notice that it was not appreciated or foreseen that the Party Wall Act would be engaged.
102. If, as in this case, where the work proceeded without the adjoining owner serving the requisite notice and it then becomes clear that a notice should have been served, Mr Sampla had three separate routes by which he could recover compensation or damages for himself and other resident family members for the resulting damage.
103. Firstly, the relevant arbitration provisions provided for by the Party Wall Act can always be operated retrospectively. These provisions involve the appointment of surveyors to resolve disputes arising in connection with any matter connected with any work to which the Party Wall Act relates. The surveyors so appointed would have jurisdiction to award appropriate compensation for any damage resulting from excavation or demolition work close to the flank wall and the adjoining planter which could and should have been, but had not been, made subject to an appropriate award prior to work starting and which undermined and damaged the foundations and the property that they supported (see sections 7(2),10(1), 10(12), 10(13)(c)) and 17 of the Party Wall Act).
104. Secondly, any failure to serve the requisite notice before work started would amount to a breach of statutory duty which would allow a court to award damages representing the compensation that would have been awarded by the surveyors appointed under the Party Wall Act for any damage caused by the work that would have been avoided had the notice provisions of the Party Wall Act been complied with.
105. Thirdly, Mr Sampla's rights to claim damages for negligence, nuisance, trespass or withdrawal of support are not affected by the Party Wall Act (see section 9). A building owner such as Mr Sampla whose party wall rights have been interfered with by an adjoining owner may recover common law damages for any loss caused by that interference if it has been caused by any one or more breaches of these causes of action. In particular, a failure to comply with the provisions of the Party Wall Act could constitute a significant negligent omission by an adjoining owner such as Rushmoor if that failure arose from a lack of due care. If that negligent omission caused Mr Sampla foreseeable damage which would have been avoided had the provisions of the Party Wall Act been complied with, Rushmoor would then be liable in damages for negligence.
106. Mr Darling contended on behalf of Rushmoor that the Party Wall Act provided no basis for a court to award the claimants damages and, equally, no basis for a court to apportion liability between two parties that had each caused a third party actionable damage. He cited an unreported decision of Mr Recorder Mawhinney from the Truro County Court, Hough and Hough v Annear and Annear, claim number 4TRO2636, 1 November 2007, in support of these submissions. In that case, the claimants were seeking damages for breach of statutory duty from the defendants. The claim was based on negligently performed work on a party wall where the particular work in question had not been covered by a party wall award. The claim was based on, and quantified by reference to, the claimed diminution in value of the property arising from the fact that the work in question was not covered by a party wall award and might have damaged, or might in the future give rise to damage to, the claimants' property. The Recorder held that the loss in question was not established and, even if it had been established, could not have been the subject of a compensation award by the surveyors had they been appointed under the Party Wall Act to resolve the dispute arising from that complaint.
107. The Recorder did not address, because there was no need to, the question of whether a court could award as damages the sum that the surveyors could have awarded as compensation had the Party Wall Act been engaged, but had wrongly not been operated, by the adjoining owner. If a building owner may not claim such loss as damages for breach of statutory duty, it could leave such a party without a remedy as a result of the offending party's failure to operate the mandatory statutory provisions of the Party Wall Act. For those reasons, and assuming that the claim is limited to the sum that the surveyor or surveyors would have awarded as compensation under the Party Wall Act, I conclude that such a claim is one of those rare claims for damages arising from a breach of statutory duty, in this case the failure to engage the Party Wall Act, that permits an affected private individual to claim and recover damages for breach of statutory duty.

(3) Rushmoor's liability to the claimants

Negligence

108. In the light of the findings of fact set out in this judgment, Rushmoor were liable to the claimants in a number of specific and cumulative ways. These may be summarised as follows.
109. Initial decision-making. The three Rushmoor personnel involved in Rushmoor's initial decision-making relating to the work, Mr Pettitt, Mr Millington and Mr Simpson, all proceeded as if they were concerned solely with a small, short-term street cleansing operation. They gave no thought to the possible impact of the work on Number 80 which adjoined the amenity area, they failed to appreciate that the work involved significant demolition and excavation work that would imperil Number 80 and its shallow flank wall foundations and they gave no thought to the welfare or safety of the adjoining occupants or to the fact that Rushmoor was an adjoining owner that had a continuing duty to maintain the adjoining owner's right to an easement of support and an absolute duty to comply with the Party Wall Act.
110. It is no answer to these complaints that these problems never occurred to any of them nor that they had had no previous experience nor any previous knowledge of these matters. The short answer is that they should not have been planning any work up to and against an adjoining occupied dwelling to be carried out on land which was not a highway but which was in Rushmoor's ownership without first taking advice from those who had relevant expertise of buildings, building structures, building foundations, building surveying and the relevant legislation and legal principles.
111. Planning the work. Mr Simpson should have arranged for three trial pits to be dug against the flank wall through the planter soil at the front, middle and rear of the site. He should also have arranged for a levels survey to be undertaken and for cross-sections to be prepared of the proposed finished excavated levels across the site onto which the sub-base course would be laid. These measures were necessary and obvious measures to take and were necessitated by matters which a competent engineer or building surveyor or other professional concerned with the detailing of paving work adjacent to an exposed flank wall on the junction of and adjacent to the proposed works should have been aware of. These matters were:

(1) The flank wall had obviously been constructed as a party wall and had also obviously been the internal dividing wall of Number 80 and its adjacent house that had obviously been built originally on the vacant site but which had previously been demolished. These details were obvious from an examination of the site and the external face of the flank wall and from an examination of the conveyance which showed that the amenity site had previously been the site of Number 82 which must have been a house adjoining Number 80. Mr Simpson had been instructed by Mr Pettit to check that Rushmoor owned the amenity site^[5] and a copy of the conveyance was held by Rushmoor and would have been readily available to him. He failed to undertake, or to have had undertaken, an appropriate inspection of the site and flank wall and he also failed to inspect, or have inspected, any copy of the conveyance that was, and would have been expected to have been, in Rushmoor's possession.

(2) The foundations of the flank wall would have been known to have been appreciably shallower than those of an external flank wall and would also be known to lie close to the external adjoining surface. The expert evidence showed that these facts were known to any competent building surveyor since they were common features of the construction of terraced houses of the type and age of those in Queen's Road, namely those constructed of brick in the nineteenth and early twentieth centuries. It should therefore have been appreciated that the proposed excavation adjacent to the flank wall, being to a depth of 215mm, would be likely to expose or even to completely uncover these foundations.

(3) The site was sloping to an appreciable extent in two directions, away from the flank wall and down the site away from Queen's Road.

(4) The amenity area was appreciably stepped between the planter and the open part of the area.

(5) The planter soil was of unknown depth but obviously extended to, and possibly below, the bottom of the planter structure. The planter had an appearance, structure and location such that it was obviously providing structural support to the flank wall foundations, particularly given that these were shallow and in need of additional lateral structural support .

(6) The planter soil was not, or was not obviously, placed on a paved surface but was, or should have been anticipated to have been, placed on the original soil. This soil, and hence the interface between the planter soil and the original material, could be anticipated to consist of disturbed or soft material to depths appreciably below the 215mm proposed excavation depth. This interface soil which would have to be excavated to provide an appropriate surface on which the sub-base could be laid.

(7) Setting out the site would be difficult unless finished surface excavation levels were provided across the site. These would also be desirable to assist in avoiding over-excavation across the site.

(8) Special excavation measures would be required to protect and support the flank wall and the flank wall foundations during and following the removal of the planter and the excavation of the adjacent material.

These considerations and measures would have identified the need to take special excavation measures to protect, and to provide additional permanent structural support for, the flank wall and the flank wall foundations.

112. Party Wall Act. Rushmore did not implement or follow the procedures provided for by the Party Wall Act and no thought was given as to whether special measures were needed in order to protect the flank wall. The Party Wall Act procedure should have been invoked from the outset, even if it was considered that no excavation would take place below the foundations or that the Party Wall Act was not engaged by the proposed work. A building owner who is an adjoining owner, which Rushmoor clearly was in relation to these works, has a strict duty to serve appropriate notices and to take all other prescribed steps set out in the Party Wall Act, even if he considers that the proposed work does not engage that Act. In this case, the Party Wall Act was obviously engaged in any event. Had the statutory procedure been followed, the necessary supporting documentation could and would only have been prepared after trial pits had been dug and inspected and a site levels survey had been undertaken. These measures would have identified the need to take special excavation temporary measures to protect the flank wall and the flank wall foundations and the further need to provide additional permanent structural support for the flank wall and the flank wall foundations.
113. Supportive measures. Mr Simpson should have designed a support system for the flank wall to replace the support provided to the flank wall and the flank wall foundations by the planter and the earth within the planter that was to be removed. The need for such replacement support, whether in the form of concrete support, a zone of retained and unexcavated material adjacent to the flank wall, a retaining wall or otherwise, could and should have been designed and provided for. The need for this additional support would have been confirmed by appropriate exploratory measures in the form of trial pits and a site levels survey had these been undertaken initially.
114. Contract documents. The contract documents provided by Rushmoor were inappropriate and insufficient. In particular, no specification or drawings were provided that identified as contractual requirements what Crowley was to do and how it was to do it in relation to all these matters:

(1) The excavation method, in the form of a method statement, that was to be used;

(2) The required finished excavation levels across the entire site that were to be achieved;

(3) The precise nature, quality and type of the finished excavated surface that was to be provided for the sub-base material;

(4) The temporary and permanent protective measures that were to be provided.

115. Supervision. Mr Simpson should have inspected the excavation work as it proceeded so as to ascertain whether the adjoining foundations were receiving continued protection and were not being uncovered or undermined by the excavation and so as to be able to address any problems if, and as soon as, these occurred.
116. Supportive measures. On 4 July 2002, as soon as he saw the dangerous state of the flank wall foundations, Mr Simpson should have required Crowley to take as a matter of extreme urgency appropriate supportive measures that would provide temporary and then permanent support to the flank wall and the flank wall foundations. Instead, he instructed Crowley to take, without any urgency, dangerously inappropriate measures which exacerbated the undermining of the flank wall foundations and further endangered them. Furthermore, he failed to provide Crowley with full and clear instructions since he only gave verbal instructions which were capable of being misinterpreted and he failed to confirm these instructions with an appropriate written method statement and drawings or sketches that clearly identified the proposed supportive measures. He also failed to inspect, or to arrange for the inspection of, Crowley's implementation of the supportive measures that he had instructed so as to ensure that these were being correctly and rapidly implemented.
117. Protection of claimants. On 4 July 2002, Mr Simpson should have arranged for the claimants to be temporarily accommodated away from Number 80 until appropriate supportive measures had been successfully implemented and completed.
118. Appropriate advice. Mr Simpson failed to take informed advice as to what should be done as soon as he saw the dangerously exposed foundations. This step was required given his inexperience in, and lack of knowledge of, building structures, foundations, underpinning and associated matters. He also failed to display any urgency in ensuring that appropriate supportive measures were urgently taken and failed to appreciate that the problem had not been caused by Crowley's poor workmanship or culpable over-excavation but had instead been caused by the difficult topography of the site, the removal of the planter, the unusually shallow flank wall foundations and Rushmoor's failure to detail the work in an appropriate and safe manner.

Nuisance, withdrawal of support, interference with the Claimants' easement of support

119. Rushmoor had supplied the flank wall and flank wall foundations of the adjacent structure of Number with an easement of support in or before 1979 when it acquired the site of Number 82 and then constructed the planter structure and the foundation's concrete blocks. This easement and its associated rights had been acquired by prescription since the planter and blocks had been constructed at least twenty three years previously. Moreover, the claimants' right of support was infringed and an actionable nuisance was created by the undermining of that support and by Rushmoor's negligent acts and omissions. These liabilities can, or arguably can, arise without negligence being established but in this case it is immaterial whether or not liability is strict since these liabilities arose as a result of Rushmoor's various negligent acts and omissions. .

Breach of statutory duty

120. The failure to operate or observe the applicable provisions of the Party Wall Act amounted to a breach of Rushmoor's statutory duty that it owed to the claimants. This failure was one for which the claimants were entitled to compensation for and which also gave rise to an entitlement to recover damages quantified by reference to the appropriate level of that compensation awarded under the Party Wall Act^[6].

(4) Crowley's liability to the claimants

Negligence

121. Potential liability. On behalf of Rushmoor it was contended that Crowley should have undertaken a pre-contract survey of the site and should have first dug trial pits to ascertain the nature, depth and possible disturbance of the flank wall foundations. It was also contended that Crowley culpably over-excavated the site, failed to adopt a safe method of excavation which did not undermine the foundations, failed to stop excavation work as soon as it became obvious that at least part of the flank wall foundations were being exposed and failed strictly and speedily to comply with and implement the instructions that Mr Simpson said that he gave Mr Crowley and instead implemented the instructions that Mr Crowley said he had received. It was also contended that even if Mr Crowley had in fact received the instructions that he said he had received, he should not have implemented them.
122. It is difficult to ascertain any breaches of duty arising from any of these allegations. Crowley had no contractual duty to check the site, particularly after it had been given a contractual assurance by Mr Simpson that it was safe to excavate up to the foundations without taking any special measures. Crowley had no duty to dig trial pits and was entitled to adopt the excavation method that it did, being an excavation method that the experts considered to be satisfactory. Crowley stopped work as soon as it first became apparent that the foundations were being fully exposed. Crowley did not over-excavate the site given the topography of the site, the poor condition of the top soil, the stepped nature of the site, the existence of the planter and its contents on the site and the shallow adjacent foundations. Finally, Crowley was faithfully following the verbal instructions that it had been given by Mr Simpson after the collapse had occurred and within the timescales that he had approved.
123. Liability - excavation. The excavation of the site started and was completed during the morning of 4 July 2002. The excavation would have involved no more than about four strips. All but the final strip would have taken a maximum of about three hours to complete and the final strip could not have taken more than about an hour to complete. Until the final strip had been started, no part of the foundations would have been exposed. Once the exposure of the foundations started, it is unlikely that it was obvious to Crowley that they were being exposed. However, this should have become clear to the operatives by the time the excavation had reached approximately the mid-point in the flank wall. Crowley could and should have stopped the excavation at that point. Had it done so, it is possible that the particularly vulnerable part of the flank wall in the middle and towards the bottom of the site where the partial collapse occurred would have retained sufficient protection that Number 80 would have been saved from the partial collapse that occurred.
124. Liability - supportive measures. Although Mr Simpson instructed Crowley to excavate a narrow strip 200mm from the side of the flank wall, Crowley should nonetheless have desisted from taking that step and should instead have insisted that Mr Simpson obtained further professional advice from Rushmoor and that Number 80 be evacuated in the meantime. This is because the danger of collapse was so obvious and immediate that any further excavation would obviously further endanger Crowley's operatives and the occupants of Number 80. Had any of those persons been injured by a collapse of Number 80 and then claimed damages from Crowley, it would have been no defence to such a claim for Crowley to contend that it had a contractual duty to comply with Mr Simpson's instructions, even though that contention would have been correct. Crowley's duty to preserve the safety of neighbours and workmen and the structural stability of adjoining structures overrode any contractual duty it owed to Rushmoor. It should not have taken any measures which endangered safety or structural stability in a situation where it was clear that the relevant measures would cause or enhance that danger.
125. The state of the exposed foundations was such that, during the afternoon of 4 July 2002, it should have been clear to Mr Crowley, as a competent contractor, that he would be exacerbating and not removing the existing danger of collapse if the operatives complied with Mr Simpson's instructions. This inference is confirmed by Mr Crowley who stated in evidence that he regarded the exposed foundations as constituting an obvious and visible danger and that he was very worried about the instructed excavation for the dwarf wall footings. Mr Crowley also stated that he only continued with these instructions because, despite his reservations, he did not feel as an inexperienced contractor that he could go behind or disobey the instructions that he had been given. In the extreme situation in which he found himself, however, these considerations did not justify his following Mr Simpson's instructions.

Other liability

126. Crowley, as an independent contractor, was strictly liable to Mr Sampla for the withdrawal of support from the foundations of Number 80 and with the interference with his easement of support and, given its negligence, was also liable in nuisance for that withdrawal.

F. Issue 4: The Causative Breaches of Contract or Duty

127. It was contended on behalf of Rushmoor, that it had not caused any damage because the damage that occurred had resulted from the over-excavation of the site by Crowley and its subsequent negligent excavation of the trench. Any failure by Rushmoor, whether of design or supervision, was not causative of the collapse or of the damage suffered by the claimants.
128. This contention is untenable and it is not possible for Rushmoor to avoid responsibility or liability for the partial collapse in this way. Had the negligent failure to dig trial holes or comply with the Party Wall Act or to specify appropriate excavation methods or to design appropriate temporary and permanent supportive measures not occurred and had Mr Simpson then properly supervised the work and given appropriate instructions to avoid the danger of imminent collapse that Rushmoor's preceding negligence had created, the partial collapse would not have occurred. There was an interlinked series of negligent acts and omissions which operated together to cause the damage. It is neither possible nor correct to separate out any of these acts and omissions nor to contend that only one isolated act or omission caused the collapse. All the negligent acts and omissions that occurred, taken together, jointly caused or contributed to the partial collapse.

G. Issue 5: Rushmoor's Contribution Liability

129. It is clear from my findings that Rushmoor was principally responsible for the collapse. The apportionment of responsibility is to be decided by applying the provisions of section 2(1) of the CLCA. I must determine what proportion of Crowley's liability to the claimants it is just and equitable to order Rushmoor to fund having regard to the extent of Rushmoor's responsibility for the damage in question. In deciding this question, I must have regard to Rushmoor's culpability and causative responsibility for the damage.
130. The partial collapse of Number 80 was caused by Rushmoor's total disregard of its obligations under the Party Wall Act and the party wall regime created by the Party Wall Act, by its total failure to appreciate the destabilising effect that the removal of the planter and the unavoidable exposure of the foundations would have on the stability of the foundations of Number 80, by the negligent initial design of the work, by Mr Simpson's failure to supervise the work and by his dangerously ignorant design of the necessary supportive works. On that basis, I find that it is just and equitable that Rushmoor should shoulder four-fifths or eighty percent of Crowley's current liability to pay damages and costs to the claimants under the terms of the compromise agreement given that Rushmoor was overwhelmingly culpable for that damage and its acts and omissions were the major and predominant cause of the claimants' damage.
131. Mr Darling submitted that any breach by Rushmoor of its obligations under the Party Wall Act and in relation to the statutory party wall regime could not provide a basis for assessing Rushmoor's contribution liability under the CCLA. However, section 7(2) of the Party Wall Act requires the offending building owner to pay compensation for, and also permits the surveyor or surveyors appointed under the Party Wall Act to resolve disputes and to award compensation for, any loss or damage which might result from any work executed in pursuance of the Party Wall Act. Such compensation would cover the entirety of the damage founding the claimants' claims. Section 6(1) of the CCLA allows contribution to be apportioned between Crowley and Rushmoor where the damage in question would have allowed the claimants to recover

"… compensation from [Rushmoor] in respect of that damage (whatever the legal basis of his liability, whether tort, breach of contract, breach of duty or otherwise)."

Clearly, therefore, both the CCLA and the Party Wall Act cover liability to pay compensation under the Party Wall Act and that liability to pay compensation can form a basis of assessing contribution under the CCLA.

132. In any event, even if Mr Darling's submission is correct that the Party Wall Act may not found a basis for apportionment, it would make no difference to the overall conclusion that Rushmoor should fund 80% of the claimants' overall recovery since its other breaches of duty were such that it was overwhelmingly culpable for and the overwhelming cause of the damage. On that basis, it would still be just and equitable that Rushmore should shoulder four-fifths of the damage.
133. There is a rough and ready way of explaining and accounting for my apportionment of the damage. There were, in broad terms, six separate but inter-linked causes of the damage:

(1) The failure to carry out investigations, and in particular to arrange for the digging of trial pits, so as to identify the depth of the flank wall foundations, the nature of the underlying topsoil and the nature of the support provided to the flank wall by the planter, foundations and topsoil;

(2) The failure to operate the relevant provisions of the Party Wall Act;

(3) The failure to replace the support for the foundations that would occur as a result of the removal of the planter and the inevitable exposure of unduly shallow foundations by the excavation exercise;

(4) The failure to properly design and detail the work and to prepare proper contract documents and designs for the work;

(5) The failure to stop excavation work before the foundations were fatally undermined; and

(6) The failure to design and then urgently to implement the necessary supportive measures to save Number 80 from partial collapse once the dangerous undermining of the foundations first became apparent followed by the negligent implementation of inappropriate measures.

134. Rushmoor can be seen to have been responsible for all six operative causes of the damage, or all five operative causes if Rushmoor's breaches of its obligations owed to the claimants imposed by the Party Wall Act must be disregarded. Crowley was jointly and equally responsible for only the last two of these causes. Each of these causes can be seen to have contributed equally to the damage. Therefore, Rushmoor can be seen to have been solely responsible for three or four of these six equal causes and to have been jointly and equally responsible with Crowley for the other two causes. On this basis, it would be both just and equitable to apportion contribution for the damage between Rushmoor and Crowley on an 80:20 split in percentage terms which, expressed in arithmetical terms, is a four-fifths:one-fifth split. This 80% responsibility can be explained because Rushmoor is fully responsible for three or four of the causes (60% of the damage) and half responsible for two of the causes (20% of the damage) and Crowley is half responsible for two of the causes (20% of the damage). This approach confirms my overall assessment that has been arrived at on a global basis.

E. Overall Conclusion

135. Rushmoor is responsible for and must reimburse Crowley:

(1) 80% of the settlement sum of £384,500 paid or payable by Crowley to the claimants;

(2) 80% of any interest paid or payable on this sum by Crowley to the claimants; and

(3) 80% of the costs that the claimants are entitled to recover from Crowley under the terms of the settlement.

(4) Rushmoor should also pay interest to Crowley on 80% of any sum that Crowley has paid to the claimants from the date or dates of Crowley's payment or payments to the claimants until judgment in these contribution proceedings.

136. Rushmoor's claim for a declaration fails.

HH Judge Anthony Thornton QC

Technology and Construction Court

Note 1    Scaled off a copy of the plan attached to the conveyance (page 329 of the trial bundles).     [Back]

Note 2    Paragraph 5 of the witness statement of Mr Pettit, Rushmoor’s then Head of Highways and Transport Services.     [Back]

Note 3    This is obvious from the wording of the conveyance which describes the land as “that piece or parcel of land being the site of the dwellinghouse and premises known as number 82 Queens Road”.    [Back]

Note 4    See, further, paragraphs 76 – 82 below.    [Back]

Note 5    See paragraph 17 above.    [Back]

Note 6    See paragraphs 96 - 107 and 112 above and 131 below.    [Back]