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

IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
TECHNOLOGY AND CONSTRUCTION COURT

		Manchester Civil Justice Centre 1 Bridge Street West Manchester Greater Manchester England M60 9DJ DX 724783 Manchester 44
		8 February 2008

 


HH Judge Thornton QC:

Introduction

1. Mr and Mrs Charlton are the joint owners of a property in Manor Crescent, Knutsford, Cheshire which they bought in May 2000 for £62,000. This property is located at the end of a terrace of houses. It is a two-storey property with a significantly sized garden and parking area. It was acquired by them in contemplation of their marriage which was the second for each of them and which took place on 7 October 2000. They moved into the property in June 2000 and they still occupy it with three of their four boys from their previous marriages. The defendant ("NSS") is a firm of structural engineers who was instructed by the Charltons to advise on two historic features of the structure, being aged cracking to the rear corner and rear elevation of the house and oversailing of the brickwork at dpc level in the left end elevation. These features had been identified in a valuation report obtained by the Charltons dated 4 May 2000 which advised that they should be inspected and reported on by a structural engineer. The Charltons now claim damages from NSS as a result of what they allege was negligent advice contained in the defendant's report dated 16 May 2000, particularly in respect of the cause and origin of the cracking at the rear of the house and as to the removal of large trees located in the garden close to it. The Charltons contend that they relied on and followed NSS's negligent advice. In consequence, they suffered loss and damage which would have been avoided had appropriate advice been given. Had such advice been received, the Charltons contend that they would have followed it and would have been spared the resulting loss and inconvenience for which they are now claiming damages.

Factual Background

2. The Charltons started to look for a family home in which they could start their married life with their four boys. They discovered what seemed to them to be an ideal property in Manor Crescent, Knutsford and, through Brigfords, the Estate Agents that had introduced them to the property, they made an acceptable offer for it subject to contract. On the advice of Brigfords, they then applied for a mortgage from the Chelsea Building Society to enable them to buy the property and Brigfords instructed a firm of surveyors, Countryside Surveyors, to carry out a valuation for the Building Society.
3. The valuation report, dated 4 May 2000, included this advice:

"ACCOMMODATION

The accommodation consists of 2, floors, 3 bedrooms and 1 kitchen. There is no garage.

INSURANCE DETAILS

(to be completed in accordance with Chelsea "Notes for Valuers")

Is there any evidence or reason to anticipate damage arising from subsidence, landslip, heave or flood?

Yes.

Are you aware of any subsidence, landslip, heave or flood in the immediate vicinity?

Yes.*

*If Yes, provide details in General Remarks 'B'

…

GENERAL OBSERVATIONS

Essential Matters

Obtain Structural Engineers report in relation to structural movement evidence particularly slippage of brickwork over DPC and movement on the rear left corner. Engineers report to include positive statements in regard to relation to the proximity of tree and root damage and condition of the drains installations. The property may be considered as a suitable mortgage security subject to the findings of the Structural Engineer.

Obtain timber and damp report in relation to localised damp readings to ground floor walls including full interior timber survey.

Roofing contractor to verify condition of roof coverings N.B. adjoining property re-roofed indicating short term life expectancy.

General Remarks

Part 'A' – Comment on the condition of the property and its location

The property offers a good sized corner plot on a Local Authority residential development containing mixed age and style properties.

The property offers scope for a programme of modernisation and refurbishment over and above the limited essential repairs. …

Part 'B' - Enter details regarding Insurance Questions answered 'Yes'

Evidence of structural cracking to the rear left corner of the building fracture cracking through brickwork and mortar joints repeats internally notably to the rear left bedroom. There is also evidence of slippage of the brickwork on the front left corner over the DPC. Tree roots and defective drains are a possible cause of the movement on the rear corner requiring further investigation by a Structural Engineer."

4. The Charltons were then advised by Brigfords that the Building Society would not be prepared to grant them a mortgage until they had obtained the recommended investigation by a Structural Engineer as well as a timber and damp report and roof covering verification. The Brigfords' representative that they were dealing with advised that a friend of his, Mr Tim Barratt, who used to work for Brigfords, was a structural engineer who would be able to provide the required report. Mr Barratt worked for NSS and Mr Charlton spoke to Mr Barratt on 10 May 2000, having been given NSS's telephone number by Brigfords' representative. Mr Barratt agreed to carry out the necessary inspection and survey that had been suggested by the valuation report for a fixed price of £141. He inspected the property soon afterwards and provided a report dated 16 May 2000.
5. Mr Barratt did not provide a systematic or detailed description of the cracks evident at the time of his inspection in May 2000 and did not undertake a survey. The relevant concluding advice confirmed that there were signs of structural movement in the house. This was described as being a slight over-hanging at dpc level to the front and left elevations and cracking to the rear elevation. The brickwork slippage was suggested to have been caused by settlement of the fill beneath the slab and the rear elevation cracking by cavity tie corrosion as opposed to foundation movement. The report recommended the replacement of the cavity ties and the removal of any large trees to at least 4.0m from the property as well as the vegetation invading the brickwork and roofs.
6. Thus, the only description of the cracking then evident to the rear elevation was as follows:

"Front Elevation.

There was a fine cracking to the mortar joints below the right had ground floor window and, also, just to the right of the window.

Left Elevation.

The pointing was poor. [There was no reference to any cracking].

Rear Elevation.

There was a crack running down from the left side of the left hand first floor window towards the widow below, a stepped crack running up to the left from the top of the left had ground floor window, and a crack running down from the right corner of this window. The area to the right corner had been re-pointed. There was also a smaller crack below the left side of the central ground floor window."

7. The critical advice in the report was in these terms:

"There were two mature fir trees, with a number of smaller trees, approximately 2.5m from the wall [located in front of the house]. …There was a mature fir tree approximately 1.5m from the rear corner. … We would recommend that that any large tree be removed to at least 4.0m from the property and that all vegetation be prevented from invading the brickwork or roofs."

The Charltons' evidence was that there were seventeen trees located at the property of which seven were within 4.0m of the house.

8. Mr Charlton also obtained an appropriate timber and damp proof report from another company recommended by Brigfords' representative.
9. Brigfords liaised with the Chelsea Building Society on receipt of the report who approved the Charltons' mortgage application but retained £2,000 for six months with a stipulation that the cavity tie and tree removal work recommended by the report should be undertaken within that timescale. The retained sum would then be paid to them. Thus, it was a requirement of the building society and a condition of the mortgage advance that the trees within 4 metres of the house should be removed.
10. Mr and Mrs Charlton cut down all the trees in the garden themselves so as to minimise the cost. The work was done between mid-July and late September 2000. It was concluded soon after they moved into the property and immediately before their wedding day. Soon afterwards, they noticed that the rear and side elevations were beginning to develop new hairline cracks and that existing cracks on the rear elevation were beginning to open up. This led to their having the cracking investigated. They stripped much of the internal plaster away to expose the internal faces of affected walls and noticed hairline cracking developing on those walls as well. The Charltons were advised that the cause of this cracking was structural movement which had itself been caused by clay heave beneath the foundations of the rear elevation which had, in turn, been caused by the cutting down of the adjacent mature Leylandii trees. After several years of uncertainty, the Charltons were advised that the house had stabilised and although it was advisable to strengthen the foundations to the rear elevation, that work should not be carried out since it might lead to a destabilisation of other parts of the house and of adjacent houses in the terrace. They have been left with a house with a significantly diminished value given the structural stigma that has resulted from this recent structural destabilisation. This diminished value is the principle loss which they now seek to recover from NSS as damages flowing from what they claim was the negligent advice that they received from NSS which they had relied on to their detriment.

Damage

11. The particular damage that the Charltons complain about is the cracking that they observed developing to the rear and side elevations which started in the autumn of 2000 and which continued to develop for about twelve to eighteen months into 2002. The Charltons do not identify with any precision the date of the onset of this cracking but they are clear that it was in the autumn of 2000. They are able to point to late 2000 with such certainty given the sequence of events leading up to their first noticing this onset of fresh cracking. These events started with their receipt of both the valuation inspection report and NSS's report in May 2000. They had then moved into the property in June 2000 and soon afterwards had cut down the adjoining trees in July and August 2000. They were married in early October 2000 and had started to settle down to newly married life. As a result of these events, the Charltons had become familiar with the existing external appearance of the house and of the various signs of possible structural movement and instability, particularly any cracking, brickwork movement and dampness, that were visible on both the exterior and interior of the house. Thus, any fresh signs of further structural movement would have been immediately recognised by them. It is for these reasons that the Charltons were able to be so confident as to the existence and the timing of the onset and development of fresh cracking
12. One further significant feature of their newly married life was that they were both smokers who were determined to keep their house free of the dangers of passive smoking and of the stale smell of tobacco smoke. In consequence, they always went outside to the rear of the house when they wanted a cigarette and they always smoked there. Whilst smoking, particularly when they became aware of what seemed to be new cracks opening up on the rear elevation, they paid particular attention to this façade of the house.
13. Mr and Mrs Charlton in their witness statement and his oral evidence described the development of the hairline cracking and the opening up of existing cracks in the rear and left elevations. For some weeks, leading up to Christmas 2000, these cracks became more and more visible. In early January 2001, Mr Charlton started to strengthen the sides of the drive-way which is adjacent to the left elevation of the house. This work involved digging trenches down the side of the drive-way to enable him to insert the wooden shuttering that was needed to strengthen this area. These trenches immediately filled with water. As a result, and given the cracking that was developing, Mr Charlton became so concerned about the cracks, the apparent problem of excessive water and the structural stability of the house generally that he asked Mr Barratt to come and look at these matters. Mr Barratt brought Mr Wells, who on his recommendation had inserted new wall ties for the Charltons in August 2000, and Mr Wells dug a hole at the rear of the house which also immediately started to fill with water. Mr Barratt examined the rear and left side facades did not comment about the cracking at that stage. Instead, he advised that the problem with water was caused by a leaking surface water drain. He located a crack in the top of the circular part of the drain as the source of the escaping water and he attributed this crack to frost damage. He advised in consequence that the drains were the cause of the water flow into the trenches and holes and he also advised that all the surface drains around the perimeter of the property should be removed and replaced.
14. Mr Charlton set to work to follow and fulfil this advice. He dug trenches around the house so as to expose the drains to a depth of about one metre. The weather was particularly bad with much rain. The trenches immediately filled with water. The water appeared to be coming from underneath the property although at least some of it would have been the rainwater draining into the trenches. Mr Charlton arranged for North West Water to come and trace the source of this water seeping into the trenches and samples were taken on 5 February 2001. These tests and the other investigations carried out by the water company showed that the source of the water was not the water mains or any leak in them. On 19 February 2001, the Environmental Health Department of the local council visited and reported to Mr Charlton on 8 March 2001 that the water source was neither sewers nor drains anywhere in the area. The inspector advised that the most likely source of the water was an underground spring or watercourse. However, Mr Charlton's subsequent investigations ruled out the possibility of there being a natural underground spring beneath the property and neither NSS nor its expert Mr Brown pointed to such a source as the source of the water.
15. Mr Charlton took the opportunity provided by the exposing of the drains to replace them because the pipes were made of lead and the water company inspector advised him that it would be good practice to replace this lead piping with modern pipes and feeds made of non-lead substances.
16. As a result of these negative investigations, and because the cracking had continued to grow, Mr Charlton again called Mr Barratt round. It was by then possible to insert a 50 pence piece into some of the old cracks, and into at least one new crack, that had by then opened up. He was also concerned that the investigations that had been carried out had ruled out leakage from the drains and an underground spring as the sources of the excessive water. All these difficulties and concerns were shown to and discussed with Mr Barratt. This meeting took place on site on about 8 March 2001. Mr Charlton pointed out the further cracking that had occurred and explained to Mr Barratt why he considered that the water source of the water in the various holes that had been dug could not have been either leaking drains or a natural watercourse.
17. Mr Barratt had no answer to the cause of the new cracking or to the source of the excessive water. It must be remembered that he had attributed the cause of the original cracking to possible faulty and corroded wall ties which had been replaced over seven months earlier. Thus, his previously suggested causes of faulty wall ties and water seepage from leaking drains or natural water courses had apparently been ruled out or, at the very least, had been ruled out by Mr Charlton and the investigations that Mr Charlton had carried out or had caused to have been carried out. All Mr Barratt could suggest was that he should monitor the cracks using tell tales and that he would advise the Charltons further once he had been able to monitor the cracks over an appreciable period of time. He returned a day or two later and installed very rudimentary telltales over cracks in three locations on the upper and lower rear elevation and on the left elevation, making nine tell tales in all. Mr Barratt returned, without informing the Charltons in advance that he was coming, on 18 April 2001 and took readings but, surprisingly, never returned again to take further readings and he never showed the Charltons his crack monitoring sheets that recorded his readings on those two visits. The record sheets only came to light when they were disclosed in these proceedings.
18. The Charltons only became aware of the visit on 18 April 2001 when Mrs Charlton met him by chance on the property outside the house. Mr Barratt pointed to one crack and said, unprompted, that the property was over fifty years old and so past it that he could not understand why the Charltons stayed there. He suggested that the Charltons should consider repointing the exterior and then getting rid of the property. Although it had been agreed at the March meeting that Mr Barratt would monitor the cracks over an appreciable period of time, which the expert evidence suggested should have been for at least two years, Mr Barratt never returned after his two readings taken on 8 May 2001. These crack monitoring record sheets were disclosed. These readings, taken over a six-week period, show some, but not apparently any significant, movement in some of the cracks.
19. I should record that Mr Barratt stated in his witness statement that he visited the property in May 2002 and his evidence was that he also visited the property on yet further occasions. The Charltons denied that Mr Barratt had made a visit in May 2002 or that they had seen him at the property on any other occasion. Mr Barratt's evidence was that he met Mrs Charlton and her brother-in-law, Mr Bobby Charlton in May 2002 but Mrs Charlton could not remember this meeting. Mr Barratt's witness statement recorded that Mr Bobby Charlton had agreed with him at this May 2002 meeting that there were no signs of movement shown by the monitors or telltales that he had installed. Mrs Charlton was emphatic that no such conversation occurred and that no such statement had been made by her brother-in-law. I am satisfied that no such meeting took place, that no other visits were made to the property by Mr Barratt except his initial inspection in May 2000 and three further visits in January, March and April 2001 and that Mr Bobby Charlton never agreed that the monitoring had shown that there had been no movement in the cracking on the external elevations. Had such further visits taken place, they would have been recorded by Mr Barratt on his crack monitoring records and had Mr Bobby Charlton made the admission attributed to him, it would have been referred to by NSS or their solicitors in the various letters written by or on behalf of NSS denying liability between December 2002 and 2006.
20. During the summer of 2001, the cracks appeared to widen and grow yet further and the hairline cracking became more extensive. Mr Charlton's brother, Mr Bobby Charlton who is a builder, went round the property with Mr Charlton. By that time, the Charltons had exposed much of the plaster on the ground and first floors, particularly the dining room, kitchen and upstairs bedrooms. This had been done, with Mr Barratt's knowledge, in order to enable the Charltons to monitor the hairline cracking in the underlying brickwork. Such cracking was evident when the plaster was exposed and during 2001 and 2002 and this internal cracking continued to expand in both size and extent. The purpose of the inspection by the Charlton brothers was to identify all the external cracking and internal cracking that had apparently opened up since the Charltons had moved into the property. This careful inspection was coupled with the brothers marking any new or recently opened crack with chalk.
21. In August 2001, Mr Charlton asked Mr Taylor, an engineer who Mr Charlton's brother had worked with and recommended, to visit the property and report on the cracking. He visited the property, had two trial holes dug in the rear and front left had corners of the house and inspected the cracking and the inside of the holes. He reported on 17 August 2001. He concluded that the property was now suffering from a clay heave situation caused by the removal of the mature Cyprus Leylandii trees from the front and rear of the property. This report noted the main area of cracking on the rear elevation had been reported on in the valuation report and NSS's report and that this historic cracking had been attributed to clay shrinkage due to tree root activity. The report also noted that further hairline cracking within the external facing brickwork to all three elevations had opened up. These newer cracks were wider at the bottom and closed to fine hairline cracks at the top thus indicating that movement was occurring at the corners of the property in an upward direction. The report recommended a period of crack monitoring before any decision was take as to the necessary remedial work.
22. No monitoring was instructed until September 2002. On 11 September 2002, Mr Charlton asked Mr Taylor to return and he installed monitoring gauges at appropriate locations He also had two further trial holes dug and he inspected these and took two clay samples away for plasticity index grading. Mr Taylor concluded that the recent movement of the property was now stabilising. Mr Taylor reported again on 3 March 2003 to the effect that his monthly readings showed that there had been very little movement of the cracks over the six month period of monitoring and that the property could safely be repaired later in the year. The monitoring was, however continued with by the Charltons and on 1 March 2004, Mr Taylor reported that there had been only minute movement in the year since his previous report and that this movement had not been significant.
23. The Charltons did not immediately undertake remedial work or pursue a claim against NSS. This delay was explained as being due to time being taken by their then solicitors to pursue their claim. However, proceedings were eventually issued on `16 May 2006, no doubt to avoid any possible limitation defence since Mr Barratt's original report had been issued on 16 May 2000. At about that time, Mr Brown took some photographs of the rear elevation which were adduced in evidence. These photographs were used by Mr Charlton in giving his evidence to demonstrate at least one significant crack that had appeared on the rear elevation which was not one described in Mr Barratt's May 2000 report and was, in consequence, obviously one which had appeared for the first time since May 2000.
24. Once the proceedings had been served, NSS instructed Mr Brown, a director in the firm of Thomasons, consulting civil and structural engineers. He inspected the property on 28 October 2006 and reported on 8 February 2007. He noted that the cracking and on the rear elevation was longstanding in nature and that there was some slight hairline or shrinkage cracking on the external and exposed internal walls.

Findings as to Damage

25. Despite this evidence, Mr Barratt in his evidence, Mr Brown in his expert evidence and Mr Sutherland in his closing submissions, all contended or submitted that there had been no cracking or hairline cracking that had opened up since May 2000. However, as I have already found, Mr and Mrs Charlton had good reason to notice and remember the developing cracking that started during the winter of 2000 – 2001. Their evidence was corroborated by Mr Taylor's observation of new hairline cracking in August 2001, by the informal crack survey undertaken by the Charlton brothers in 2001 and by the photographs taken in 2006. It is also supported by the ready way that Mr Barratt suggested in March 2001 that telltales should be installed and by his then installing them. These telltales would have been unnecessary had there been no fresh cracking or cracking movement and it is most unlikely that they would have been recommended by Mr Barratt unless he had observed during his January and March 2001 visits apparently fresh cracking on the rear elevation .
26. Further support for the finding of the appearance of new cracking is gained by a comparison of Mr Barratt's May 2000 report with Mr Brown's January 2007 report. No precise comparison can be made since Mr Brown prepared a detailed and thorough report and Mr Barratt a sketchy and somewhat superficial one. Furthermore, the two reports were prepared nearly seven years apart. However, in general terms, Mr Brown can be seen to be describing a more extensive crack pattern in evidence on the external facades of the house than Mr Barratt described. That difference could only have occurred because further cracking had opened up since Mr Barratt had reported in May 2000. Finally, I am reinforced in making these findings by my observation of Mr and Mrs Charlton and Mr Barratt and by hearing their oral evidence. Mr and Mrs Charlton were both credible and reliable witnesses whereas Mr Barratt's evidence was both confused and inconclusive.
27. I therefore find that there opened up at least one major crack on the rear elevation, that several cracks already present widened appreciably and that significant hairline cracking appeared on the external elevations, particularly on the left elevation with less extensive hairline cracking on the rear elevation. Significant hairline cracking also opened up on internal walls that had been exposed by the plaster stripping that was undertaken in 2001. This movement started in about November 2000 and continued until at least sometime in 2002. There has been no evidence of further cracking or movement since at least 2003.

Cause of the Cracking and Movement

28. The Charltons, relying on Mr Taylor's oral evidence and on his many reports in the years since 2001, contended that the movement and cracking was caused by the removal of the 17 trees, and in particular the mature Leylandii, situated close to the house. The causal link between that removal and the subsequent cracking postulated by Mr Taylor is the well-known phenomenon of clay heave. Certain species of mature tree located close to buildings have extensive tree roots which extract much water from the adjacent ground. Where the ground is clay-based, the water extraction process will cause the clay to desiccate and shrink. If the trees in question are removed, the water extraction process will instantaneously cease and the clay will swell rapidly until it is rehydrated. This clay heaving process will cause foundations above and in the immediate vicinity of the heave to move upwards with resulting cracking and structural movement.
29. Although Leylandii is not one of the most dangerous species in terms of causing desiccation in clay soils, Leylandii are capable of inducing clay heave, particularly if they are in excess of about 10 metres in height and within 4 metres of the potentially affected property. Current BSE recommendations are to the effect that foundations of at least 900 centimetres in depth should be provided for houses and all trees within 4 metres of a house should be removed or curtailed in height. However, such removal should usually be undertaken gradually since the rapid removal of trees causing desiccation can lead to a rapid rehydration of desiccated clay and consequent swelling and heave. If a gradual reduction programme of tree-based water extraction is undertaken, by pruning, lopping, height reduction and root curtailment, the dangers posed by the tree can be eliminated without endangering adjoining structures with clay heave.
30. The difficulty facing NSS in advancing their case that no loss or damage occurred from clay heave is that Mr Brown could not provide any answer to what the cause of the cracking was if not from clay heave. He was adamant that no cracking had occurred despite not having inspected the property until 6 years, almost to the day, from when the cracking complained about first started and well over 4 years after all cracking movement had ceased. When asked directly to consider the hypothetical situation that such cracking had occurred, he stated that he was unable to provide any suggestion as to its cause.
31. NSS was left with contending that the Charltons had not satisfied the burden of proof that lay with them that the cause of the cracking was clay heave. This contention was supported by an analysis of three crucial features of the evidence, that relating to the height of the trees that were cut down, that relating to the allegedly previously desiccated clay and that relating to the nature of the damp and soft clay subsoil revealed in the test holes dug in 2001, 2002 and 2006. This analysis led to the submission that the only possible cause of the cracking, if it occurred at all, was an adjacent source of naturally occurring water such as a spring or watercourse.
32. Leylandii Trees Removal in 2000. NSS contended that the Leylandii that were removed could not have been more than 5 – 6 metres in height. At that height, so the evidence suggested, the Leylandii were insufficiently mature to be able to cause significant desiccation in clay soils. This contention was largely based on Mr Barratt's evidence that the trees adjacent to the house were only ¼ to ? of their full height of about 20 metres when he inspected the property in May 2000. However, these trees were described by Mr Barratt in his contemporary report as being "large" and the adjacent fir trees as being mature. These descriptions belie trees that are only one third of their natural height. Moreover, the Agent's particulars of the property prepared in early 2000 show some of these trees that are adjacent to the house in a photograph of the premises. It is difficult to gauge accurately the height of the adjacent Leylandii but their height is consistent with Mr Charlton's estimate of the trees he cut down as being at least 7.5 metres in height and Mr Barratt's description of them as being large. Indeed, as Mr Taylor concluded, the Leylandii were probably at least 12 metres in height.
33. There was also evidence of the nature of the tree roots found in the trenches that Mr Charlton excavated. These were stated to be extensive and long, thick and deep. This evidence also suggests that the Leylandii that they had been attached to were already nearing maturity which is at a height of at least 20 metres.
34. I conclude that the Leylandii in the immediate vicinity of the house were at least 8 – 10 metres in height and may have been as tall as 12 metres.
35. Clay. Mr Brown's principal basis for contending that clay heave could not have occurred was that the suction tests and Atterberg limits tests (involving the moisture content, liquid limit and plastic limit of the samples) that were carried out on samples removed from a trial hole dug in 2006 in the rear corner of the property close to the damaged rear elevation showed that the clay in that location showed no sign of having been desiccated in the past or of currently being desiccated. In consequence, he concluded, there had never been any desiccation or clay heave in the vicinity of the rear elevation. These tests appeared to be conclusive of the current state of the sample but Mr Brown was unable to state that these tests provided any guide to the possible desiccated state of the clay six years prior to the samples being taken or of the ability of clay to recover its properties over time following rehydration from the desiccated state. It was clear that clay can recover its normal state very quickly and I conclude that once clay has rehydrated following desiccation, it is no longer possible to identify its previously desiccated state using suction or Atterberg limit tests.
36. It follows that the tests undertaken for Mr Brown provided no evidence of either desiccation or lack of desiccation in the clay subsoil adjacent to the foundations of the rear elevation in 2000.
37. Moisture Content. The evidence pointed to the subsoil in the vicinity of the rear elevation being very damp or even saturated in the light of the observed state of trial pits dug in that location in January 2001 for Mr Barratt, in August 2001 and September 2002 for Mr Taylor and in October 2006 for Mr Brown. Similarly, the subsoil in the vicinity of the left side and front elevation was damp, but much less damp, on each of these occasions since a second trial pit was dug in the front corner of that elevation. I must first discount the evidence of freely flowing water within the trenches and holes found in January and March 2001. Mr Charlton was clear in his recollection that this period, when he started to open up the drive-way and surface water drain trenches, was a very wet and stormy period and the ingress of water can now be seen to have been caused by surface rainwater accumulating in the comparatively impervious holes created in the clay.
38. It is noticeable that the observed level of water presence in the holes dug in the relevant location in the vicinity of the rear corner of the house slowly decreased over time. In January 2001, the trial pit dug in Mr Barratt's presence was filled with water as was clear from Mr Charlton and Mr Barratt's evidence. By August 2001, Mr Taylor reported that the clay-sided pit had wet, brown, plastic clay sides with water seeping freely into the excavation. By September 2002, Mr Taylor reported that water ingress was much slower and considerably less than as reported in August 2001. Finally, in October 2006, Mr Brown reported that the clay was soft wet and silty but with no reported seeping or ingress of further water. The lesser water content of the second trial pit location at the front of the property showed equivalent decrease in moisture content and that the levels of water content as being consistently less than for the first trial pit. Mr Charlton was also able to give some relevant evidence from the tree removal operation. He and his helping family members had dug holes to remove the tree stumps and found the ground to be particularly dry and hard.
39. This evidence suggests that the clay soil was very dry in locations adjacent to the rear location of the house in 2000 prior to the removal of the trees, that immediately following their removal the clay became saturated from the particularly wet winter and that once the effects of that excessive rainfall were removed, the area remained moist. The area adjacent to the rear elevation was apparently moister than the area adjacent to the side elevation and that additional level of moisture was probably the result of localised natural conditions. The moisture content would, in any year, vary depending on the season with the summer months being drier than the winder months and the variation in moisture content evident in August 2001 compared with September 2002 or October 2006 was not apparently significant.
40. What is significant is the obvious difference in moisture content in August 2000 at a time when the Leylandii were still standing compared with the corresponding moisture content on all subsequent occasions that it was observed. This evidence points strongly to the conclusion that the removal of the Leylandii had a significant influence on the water content of the surrounding clay and to the further conclusion that the surrounding clay had been in a desiccated state whilst the Leylandii were mature and present and in a rehydrated state once they had been removed.
41. I also conclude that there was no evidence of any significant alternative source of the moisture, particularly in the form of a watercourse or spring. Thus, although the only other cause of cracking and structural movement could have been localised softening of the subsoil beneath the foundations from extraneous natural water sources, no such source was ever identified.
42. It follows that the evidence clearly points to the cracking in 2000 – 2002 having been caused as a result of rehydration of the subsoil previously desiccated by Leylandii tree roots.

Negligence

43. Three potential breaches of duty by Mr Barratt are relied on. These were, firstly, that Mr Barratt failed to identify the nature of the subsoil in the vicinity of the cracking he was investigating and was not aware that that historic cracking had probably been caused by the rehydration and heave of the clay subsoil. Secondly, Mr Barratt wrongly advised the Charltons to have all the mature or tall Leylandii trees removed. Instead, given the dangers of rehydration, he should have advised them to adopt a programme of pruning, loping and root curtailment under the guidance of an arborculturist so as to eliminate the possibility of rehydration and heave. Thirdly, Mr Barratt failed to identify the cause of the cracking when inspecting the cracking and water-filled trenches in January and March 2001.
44. Mr Barratt's Report. The scope of Mr Barratt and NSS's duty was derived from his instructions which were to report on the matters that the valuation report had advised should be investigated by an engineer. In summary, these were to report on the proximity of tree and root damage to, and the movement in, the rear left corner of the property. In other words, he was to report on whether the existing historic damage had been caused by adjacently situated trees and tree roots and whether the existing trees posed a potential future threat to the structure of the house.
45. In order to undertake his exercise, Mr Barratt needed to consider whether there was clay subsoil which was capable of being desiccated and of shrinking or swelling and also to consider the moisture content of that subsoil to see whether there was the possibility of localised withdrawal of support beneath the foundations due to softened subsoil and reduced bearing capacity at any point. He also needed to consider the existing state of the subsoil to see whether there was any evidence of desiccation. Finally, he needed to ascertain the nature and depth of the foundations in the area of concern so as to ensure that they were of sufficient strength and depth.
46. Mr Barratt did not have any trial pit or trial hole dug. Indeed, he considered that the subsoil was a sandy material as is clear from his report in which he stated that the property might be founded on non-shrinkable strata such as sand. He elaborated on his view of the nature of the subsoil in his evidence, he stated that he was satisfied that the subsoil was a non-shrinkable material. This view was based entirely on his experience of properties in the Cheshire area.
47. As a result of his views as to the nature of the subsoil and of his failure to create and inspect appropriate trial holes in the vicinity of the foundations of the rear elevation, Mr Barratt did not consider whether the structure was at risk from shrinkable or expandable subsoil material. Furthermore, he did not consider, evaluate or advise on the possible dangers of desiccation and rehydration posed by the subsoil to the foundations and structure of this particular house. It would seem that this failure occurred, at least in part, because Mr Barratt was in a hurry when undertaking his inspection. Mrs Charlton was informed by the previous occupant of the property that that occupant had seen Mr Barratt making his inspection and informed Mrs Charlton that he was only at the property for about fifteen minutes. This was denied by Mr Barratt but such a short visit would be consistent with the somewhat scanty report he wrote. Moreover, Mr Barratt was unable to give any coherent reason why he did not dig a trial hole or why he could be confident that the subsoil was not one containing shrinkable clay save that it was his experience of the general area where the property was located that the subsoil in that area was invariably a non-shrinkable sandy or sandy-clay material. This view was not backed by any more detailed, scientific or empirical evidence.
48. Removal of Leylandii. Mr Barratt therefore recommended, incorrectly, that there was no danger posed by the adjoining trees and that the presently observable historic damage was not caused by trees or tree roots. However, as a precaution, he also advised that the trees in the vicinity of the property should be removed. He explained in evidence that this advice was based solely on the BSE recommendation that tall trees less than 4.0 metres from a house should be removed whatever the nature of the subsoil and, when pressed, he stated that he gave no thought to the inherent contradiction of concluding that the subsoil was non-shrinkable yet the removal of adjacent tall trees was desirable.
49. The two experts agreed this significant matter:

"Mr Taylor and Mr Brown agree that the recommendation to remove all trees was inappropriate without a detailed knowledge of the foundation depths and nature of the ground conditions. It would have been a more prudent recommendation to establish those details and consult with an arborculturist. Some degree of tree management would have inevitably been required to control the tree root activity with the large number of trees that were present within the influencing distance of the property."

50. In the light of his failure to investigate the nature of the subsoil prior to making this inappropriate recommendation, it is clear that Mr Barratt failed to exercise reasonable skill and care in making the recommendation he did and in not advising on the potential dangers posed to this house of rehydration and clay heave. Furthermore, he should first have obtained, with the Charltons' permission, advice from an arborculturist sanctioning the removal of the Leylandii as opposed to the adoption of a gradualist approach involving the phased reduction of the Leylandii's ability to extract water from the surrounding clay subsoil.
51. Mr Barratt's subsequent inspections and monitoring. Mr Barratt's additional failure was in relation to his inspections and monitoring following his return visits to the site in 2001. He was shown clear evidence of recent structural movement and of excessive substrata hydration and wetness. He could also have inspected the open trial pit and ascertained that the subsoil was a clay material and could have observed evidence of extensive tree root presence. He therefore failed, to identify that, at the very least, there was a danger that the rear of the property was in the throes of, or was at risk of future, clay rehydration damage.
52. I conclude that Mr Barratt failed to exercise reasonable skill and care in each of these three respects.

Causation

53. It was contended that the Charltons have failed to prove that these acts of negligence caused the loss that is claimed. In particular, it was contended that no evidence of what an arboriculturist would have recommended had one been consulted. It was likely, it was contended, that no advice would have been given to undermine the advice of Mr Barratt that the trees should be removed completely and in one operation.
54. This contention overlooks two aspects of the evidence. Firstly, it is the case, and is certainly a reasonable inference, that a trial pit dug in May 2000 would have revealed evidence of the clay-like nature of the subsoil and of its desiccated state. This would have put Mr Barratt on notice that the subsoil was susceptible to clay heave. Secondly, the evidence suggests that an arboriculturist would have recommended, and moreover commonsense would dictate, that the adjacent trees should have been lopped and pruned and the tree roots should be treated and curtailed in size and extent so as to eliminate the risk of rehydration. It is clear that both an arborculturist and commonsense would both have dictated that instant removal should not be contemplated but that a phased reduction of the risk of rehydration should be undertaken so as to remove the risk of further desiccation in the future.
55. I conclude that the evidence shows that the Charltons, who clearly relied on the advice to remove the trees, suffered some damage in consequence. This was, in general terms, the cracking and other related structural damage and the uncertainty and anxiety resulting from the appearance of this damage and from Mr Barratt's failure to identify the damage once it occurred. Had a phased programme of lopping, height reduction and root curtailment been adopted, the damage and subsequent stigma would not have occurred.

Damages

56. It is now accepted that the property does not require any substantial remedial work and that additional reinforcement of the foundations below the rear wall should take place for additional security and peace of mind. However, additional reinforcement or strengthening work is not structurally necessary. If it is resorted to, it might cause differential structural movement in either the Charltons' house or in other properties in the terrace of houses to which it is joined. In consequence, the Charltons have been advised not to undertake anything other than cosmetic repairs and to live with a property which is structurally sound but which now suffers from significant stigma given its recent structural history and the lack of any subsequent further strengthening and reinforcement to the foundations.
57. In consequence, Mr and Mrs Charltons' claim is for damages that represents the diminution in value the property that has resulted from its having acquired a stigma as one which is susceptible to structural damage from clay shrinkage and swelling but whose foundations, nonetheless, remain both unremedied and, in general terms, unremediable.
58. Mr and Mrs Charlton instructed a valuer with extensive local knowledge who considered that the present value of the property with no work having been done to the foundations would be £20,000 less than it would have had it not been subjected to the damage and uncertainty that has occurred. This figure was derived from the current market value of the property (£145,000) and the value it would have but for the damage and uncertainty and consequent stigma (£165,000). The valuer called by NSS agreed that the property's value had been diminished due to this stigma but was unable to provide a reduced value of the property in its present condition. This was because he lacked instructions from NSS to provide a diminished value given NSS's insistence that no damage had been caused to the house in the first place. The value did not, however, dissent from the reduced value of £20,000 provided by the Charltons' valuer.
59. This diminution in value figure was arrived at using autumn 2007 values. NSS contended that the valuation should be at 2000 values, when the Charltons' reliance on NSS's negligence occurred. Moreover, the effects of the negligence and the knowledge that there was no requirement to underpin the house were fully established within a relatively short time and the increased diminution in value resulting from that valuation being arrived at in 2007 rather than in, say, 2001 was attributable to the Charltons' failure to mitigate their loss and to delays in pursuing their claim which were not of NSS's making. Thus, since no comparable figures were produced for 2000 or 2001 values, the Charltons had failed to prove their loss and should recover nothing.
60. There is nothing inherently wrong in principle in valuing a diminution in value loss at a later date than the date of the breach. The guiding principles are that the based date of the valuation must be one which is reasonable, is one which gives rise to a loss which is directly linked to the breach, is one which results from no break in the causal chain and is one which does not arise and is not attributable to any failure to mitigate.
61. I am concerned with a lengthy period between the summer of 2000 and the autumn of 2007. However, much of that period resulted from the considerable uncertainties that resulted from Mr Barratt's negligent prepared report and subsequent advice. That negligence included his continuing failure to advise on the true cause of the cracking or to be prepared to recognise that there was any recent onset of further cracking. Given that background and given that the damage that was occurring was not obviously structurally significant, it was necessary to undertake a lengthy period of monitoring and observation before a final and conclusive answer to the problem of damage and repair could be arrived at.
62. It is true that these uncertainties had been resolved by, as I find, the end of 2004 and that proceedings could reasonably have been started about two years earlier than they were. However, from the moment that a claim was first intimated in 2002, NSS and Mr Barratt were adamant that there was no liability, breach, damage or loss. It is a tall order for those with modest means to pursue a professional negligence action of modest size against insured professionals in the face of such a string of adamant denials, all of which have turned out to be disproved. Thus, until faced with the imminent disappearance of their claim by limitation, it is understandable that the Charltons were prepared to rely on less formal means than litigation to pursue what turns out to have been a valid and reasonable claim.
63. I therefore conclude that, in the circumstances of this case, it was reasonable for the Charltons to pursue their claim based on 2007 values. Furthermore, there is no intrinsic reason why the particular loss in question should not be valued as at the date of the trial. No authority was cited that required the court to adopt a different course from that which is both reasonable and practicable. I would finally observe that if an earlier date was chosen, the Charltons could now claim interest on that earlier figure from the date of valuation until the date of judgment, possibly at compound interest rates and that NSS failed to identify any earlier date valuation in order to displace the Charltons' valuation.
64. In consequence, and for all these reasons, I award the Charltons £20,000 by way of damages for diminution in value. Since this is a figure based on current values, it will not carry any pre-judgment date interest.
65. The Charltons also established the following heads of expenditure directly caused by, and resulting from, NSS's negligence:

(1) £1,000 to repair the cracks that have appeared in the property. This is an agreed figure.

(2) £350 and £1,532.71 for the hire of a chainsaw and mechanical digger to remove the trees which did not, on my findings, require to be removed.

(3) £1,217.50 and £193.88 for the pre-litigation fees of Mr Taylor's firm.

66. Claims were made for the cost of replacing the drainage system. These costs did not flow from the established negligence and were, in any event, the result of improvements in the property which were needed and which were reasonable to carry out in any event. These claims fail.
67. The Charltons are also entitled to general damages for inconvenience and distress over a 4-year period during which they were affected by the consequences of Mr Barratt's negligent and cavalier professional behaviour. I assess this period as being one of 4 years because I consider that this case could have been brought to trial 2 years earlier than it was. The Charltons lived in conditions of much discomfort and disagreeableness since they reasonably left the interior walls unplastered during the monitoring period at much distress to harmonious family life. For example, Mrs Charlton understandably felt somewhat inhibited in holding family gatherings in her dining room and kitchen and her sons from entertaining their friends in this period due to the lack of decoration to the interior of the house.
68. I assess the fair sum for that period for the family of 5 to be £5,000. This claim, too, does not carry additional pre-judgment interest.

Conclusion

69. There will be judgment for £29,294.09. The parties must seek to agree any interest award on the small amount of this overall sum which carried interest from the date of the loss being incurred. I also suggest that a lump sum in costs should be assessed and paid to the Charltons, since I consider that a lump sum award without assessment should be considered so as to avoid the cost and further delay that would result from a detailed assessment. The terms of the order giving effect to this judgment need to be agreed. If these matters cannot be agreed within 14 days of the receipt of this judgment, the parties are each to send to the court written submissions on these matters by 7 March 2008.
70. This judgment will be formally handed down in open court on 3 March 2008. However, the terms of this judgment are formally published by the receipt of the judgment by the parties and no appearance in court on 3 March 2008 will be expected.

HH Judge Thornton QC