1. LORD JUSTICE PETER GIBSON: At Rolle Barton, Otterton, Devon there were in 1998 some disused farm buildings adjoining which was some agricultural land bounded by a mill stream. Those buildings are in two sections joined together though they do not run in a straight line. The smaller section, now called Phoenix Barn, runs north-south. It is quadrilateral in shape, one of its sides being longer than the other. It joins the larger section of the buildings at an angle. Its roof is at the same height as that of the larger section though Phoenix Barn is a slightly broader building and its walls, both front and back, extend beyond the walls of the larger building. Its roof also protruded both east and west beyond the end of the roof of the larger section. There is a parapet between the two roofs. The larger section runs north-north-east to south-south-west. If the line of the junction between the two buildings as shown by the line of the parapet is extended westward it runs at right angles to the western side of the larger section; similarly if extended eastward. The buildings have windows or doors on three floors.

2. In 1998 to 1999 a property developer, Countrywide Properties Ltd ("Countrywide"), converted those buildings into three residential units. They were called Plots 1 to 3. This was part of a larger development of a small estate. Plot 1 consisted of Phoenix Barn, with a comparatively small area to the front between the building and the estate road and a substantial area to the west intended to be the garden, extending beyond the north-western end of Phoenix Barn and going down to the mill stream. The area of the garden is 1,114.56 sq metres.

3. The larger section of the buildings was divided into two: Plot 2, now called The Shippen adjoining Phoenix Barn, and Plot 3, now called Bicton View adjoining The Shippen to the south. Plot 2 comprised the northern half of the larger section and a small area of land between the building and the estate road to the east and a larger area between the building and the mill stream to the west that was intended to be the garden for The Shippen; the garden area was intended to be 410.78 sq metres. Similarly Plot 3 had a small area at the front to the east and a larger area to the west as the garden for Bicton View. Architects in 1998 prepared a site plan for the whole development, showing how the site would look when the development was completed. The plan included in the usual way detailed directions as to what was to be done at various places on the site. Thus it showed where new buildings, fences and walls were to be placed. When the plots were marketed a draft transfer was available. It was intended that each plot to be transferred would be identified on a plan annexed to the transfer, and that plan was a reduced copy of the site plan with coloured lines to identify the boundaries of that plot. The site plan, and consequently the draft transfer plan for each plot, showed the boundary between Plots 1 and 2 as following the line of the junction between Phoenix Barn and The Shippen, that is to say at right angles to the eastern and western sides of The Shippen and so extending to the estate road at the front and down to the mill stream at the back. It also showed that the boundary between Plots 2 and 3 also ran at right angles to the side of the building and so was to be parallel to the boundary between Plots 1 and 2.

4. The land to the west of the buildings sloped from north to south. It was intended that a paved patio area or terrace would be built at the rear of each of the three plots. To support those features Countrywide intended to build a short stretch of retaining wall between Plots 1 and 2 and another between Plots 2 and 3. Accordingly on the site plan was written, in the area for each intended garden, "terrace with paved patio". In the area for the intended garden for Plot 2 was written "retaining walls rendered" with an arrow pointing to that part of the boundary line between Plots 1 and 2 which lay close to The Shippen building and another arrow pointing to the boundary line between Plots 2 and 3 just west of the building. It was also intended that a fence would separate Plots 1 and 2 and accordingly the site plan contained a notation, "post and rail fencing to match existing", written on the plan with an arrow pointing to the boundary line. What "existing" referred to is not explained.

5. The Claimant, Mrs Vivien Harvey, was the first to purchase any of Plots 1, 2 and 3. She visited the site on 10 November 1998 when the area of land to the west of the buildings had the appearance of a large undivided ploughed field. However she saw at the southern end of Phoenix Barn a low retaining wall which ran westward and which appeared to her to be of recent construction. She expressed interest in purchasing Plot 1, and by 19 November 1998 her solicitor was sent documentation relating to it. She saw the plan attached to the draft transfer, and that had all the features to which I have referred when describing the site plan.

6. Mrs Harvey exchanged contracts for the purchase of Plot 1 on 11 December 1998. The contract described the property which she was agreeing to buy as "Plot 1 on [Countrywide's] Estate known as Rolle Barton more particularly described in the Plot Transfer". The Plot Transfer was the form of transfer annexed to the contract.

7. In late January or early February 1999 Countrywide erected a post and wire fence adjacent to the retaining wall but starting on the south side of that wall. That fence ran westward down to the mill stream. A close boarded fence has since been put up for the first few metres closest to the building to give privacy as between Phoenix Barn and The Shippen. In February Mrs Harvey asked Countrywide's agent, Mr Perkins, if she could start landscaping her garden and making the fence stock-proof even before the purchase was completed. He agreed, and from mid-February for about two months she started laying out the border alongside the fence. Mr Perkins saw and expressed his approval of what she was doing. She planted nearly 50 plants and shrubs in that border.

8. Completion of the transfer to Mrs Harvey of Plot 1 took place on 1 May 1999. The Transfer was expressed to be of "the Property together with the Dwelling". The term "the Property" was defined as "Plot [then a blank] Otterton Barton shown edged red on the Plan marked 'Plot 1' being part of the Estate". The estate was shown edged green on the site plan. "The Plan" was the plan annexed thereto. It appears that the plan may not have been so annexed on 1 May 1999 as it was not signed by Mrs Harvey until later in May. It was the same as the plan she had already seen save for one alteration not material to this appeal. Her title was later registered at the Land Registry. The registered plan shows the boundary with Plot 2 not on the line where the fence had been placed but as on the site plan.

9. In May 1999 the Claimants, Mr Gareth Beale and his wife Elizabeth, became interested in purchasing Plot 2. Mr Beale says in his witness statement that when he viewed the property for about 10 minutes or so, the garden was entirely unformed and comprised bare earth. To the west of the property there was the fence which appeared to be the northern boundary of a garden, but they did not check the boundaries because they were identified on the plan shown to them. The Beales exchanged contracts on 17 June 1999. The contract was in similar form to that for Mrs Harvey. The Transfer of Plot 2 was completed on 24 June 1999. The property transferred to the Beales was "Plot 2 Rolle Barton shown edged red on the Plan being part of the Estate". The Plan was again a reduced copy of the site plan and showed the boundary between Plots 1 and 2 in the way I have already described and as parallel to the boundary between Plots 2 and 3.

10. The Beales became the registered proprietors of The Shippen and the Land Registry plan shows the boundaries between Plots 1 and 2 and 2 and 3 as parallel. Also in July 1999 Plot 3 was sold to Mr and Mrs Darryl Hackney. Mr Beale claims to have noticed that the fence between Plots 1 and 2 was in the wrong place after contracts were exchanged but before the transfer and that he told Countrywide and obtained a promise from it to put the fence in the correct position. At the trial no finding was made about that, but it is clear that by August 1999 Mr Beale had made his complaint known to Countrywide and to his neighbours. Countrywide sent its estate agent, Mr Williams, who had been handling the sales to the site. He made detailed measurements and produced a sketch plan. This showed that the boundaries on the ground between Plots 1 and 2 and Plots 2 and 3 were far from parallel and that the western end of the Beales' garden was 2.2 metres narrower than at the eastern end. Subsequently, for the purpose of the trial, a surveyor, Mr Marshall, has calculated the area in dispute as 49.95 sq metres. That, I should explain, is on the footing that the boundary line is the line marked by the southern edge of Phoenix Barn such as is, for example, visible from the line of the parapet where the roof of Phoenix Barn and the Shippen join ("the Beales' line") and not the line of the internal party wall visible internally. According to Mr Marshall, the internal southern wall at the lower ground floor level of Phoenix Barn was parallel to the northern side of Phoenix Barn whereas the line of the separating wall upon the upper ground and first floor levels was on a line parallel to the Beales' line but set a little to the north. Mr Marshall has produced a plan which, like Mr Williams' plan, shows the retaining wall as being slightly out of line with the Beales' line, and the fence, being to the south of the retaining wall, has increased that divergence from the Beales' line.

11. Countrywide agreed with Mr Beale that the fence had been placed in the wrong place. It told Mr Beale that the fence would be put into the correct position. It sought to obtain Mrs Harvey's consent to the re-alignment on 29 October 1999. It offered to make good any damage or disturbance. Mrs Harvey refused.

12. Proceedings were commenced on 4 January 2002 in the Exeter County Court. The Beales sought a mandatory injunction requiring Mrs Harvey to re-align the fence. (It has never been suggested that the retaining wall should be re-aligned.) Mrs Harvey denied the Beales' claim. She said that the land to the north of the fence already belonged to her at the time of the Beales' purchase. She pleaded in paragraph 12, so far as material:

"12 In the alternative, and should the court find that on its true construction that the Defendant's contract did not include all of the said land to the North of the said fence, then the Defendant pleads as follows:

.....

b. i. [Countrywide] erected the said fence purportedly as a boundary fence. Immediately following the erection of the said fence, in February, March and April 1999, and with the consent of the Developer during the period prior to completion of the Defendant's purchase, the Defendant/her servant or agents dug out a strip of land immediately to the North of the said fence and there planted flower beds.

ii. The Defendant's said activities and the products thereof were observed on numerous occasions by ..... Mr Perkins who raised neither comment, complaint nor query upon the same and made no reference to any defect in the position of the said fence until September 1999.

iii. In the circumstances the Developer cannot, as against the Defendant, in good conscience assert the position of the boundary as being other than that marked by the said fence, and, as the Developers' successors in title, neither can the claimants."

13. Mrs Harvey counterclaimed for a declaration that the true boundary lay along the line of the retaining wall and fence.

14. Mrs Harvey then applied under CPR Part 24 for summary judgment. On 18 July 2002 District Judge Wainwright rejected that application. Mrs Harvey's appeal was dismissed by His Honour Judge Overend on 4 October 2002.

15. The trial commenced before Mr Recorder Lambert on 27 March 2003. In the course of his opening, Mr Treneer, appearing for the Beales, took a point on paragraph 12 of Mrs Harvey's Defence. That had been the subject of a submission by Mr Ball, appearing for Mrs Harvey, in his skeleton argument. Mr Ball had submitted in a paragraph headed "Estoppel" that if the disputed land had been conveyed not to Mrs Harvey but to the Beales, then Mrs Harvey relied on the conduct of Mr Perkins, Countrywide's agent, as giving rise to an equity in her favour in circumstances in which the erection of the fence was intended to mark the boundary. Mr Perkins had represented to her the position of the boundary. She had reasonably relied on the position of the fence as marking the boundary and in consequence spent time and money improving the land, and Countrywide did not mention any other position for the boundary until after Plot 2 had been sold to the Beales. Mr Ball submitted that Countrywide was estopped from asserting a contrary contention and that Mrs Harvey's "proprietary equity" was available also against the Beales as successors in title to Countrywide, Mrs Harvey being in actual occupation. He referred to Section 70 (1) (g) of the Land Registration Act 1925.

16. Mr Treneer submitted that an estoppel was not pleaded in the Defence and it was too late to amend the pleadings. The Recorder ruled that estoppel had not been pleaded sufficiently, the Beales being entitled to know the variety of estoppel asserted against them. Mr Ball then formulated a proposed amendment in which it was stated that the estoppel relied on was equitable estoppel arising out of the conduct or representations of Mr Perkins and that it might amount to proprietary estoppel. The Recorder then ruled that the proposed amendment was inadequate because it too failed to identify the type of estoppel relied upon. He said that justice would not be achieved by permitting an amendment to allege some form of migratory species of estoppel, that a late amendment would jeopardise the trial as the Beales would seek to join Countrywide and would need time to consider the matter. Accordingly the amendment was refused, and the Recorder did not have to rule on the substance of the estoppel point.

17. Oral evidence was given for the Beales by Mr Beale and Mr Williams, and for Mrs Harvey by Mr Hackney and Mrs Harvey herself. There were also witness statements for the Beales from Mrs Beale and Mr Perkins, and for Mrs Harvey from a Mrs Brown who took photographs in February 1999 of the back of Phoenix Barn.

18. On 28 March the Recorder gave judgment. He said that he should look at and interpret the conveyance and plan and define the common intention of the parties from the documents used alone; that the land sold was defined by the conveyancing documents; that the meaning of the Transfer should be accorded an objective, reasonable test; that the land defined by the Transfer should be so defined by reference to the plan accordingly, and that any other evidence of opinion as to the boundaries was inadmissible. He said that he would resolve, first, what was sold to Mrs Harvey and where the boundaries of her property lay. He described as very much matters of impression what was signified by the plan. He said that it was plain that the retaining wall was not the boundary and that the boundary was what was at one time simply a hypothetical line on a plan with no physical feature save the buildings. He rejected Mr Ball's submission that there was any latent ambiguity. He said that a reasonable person at the site with the plan when the contracts were signed would see the boundary in accordance with the plan and that it was parallel with the boundary between Plots 2 and 3.

19. The Recorder referred to Lyle v Richards [1866] LR 1 HL 222, cited by Mr Ball, but derived little assistance from it. He described the plan as showing a cartographic line on a map showing the boundary and said that it did not do so with reference to the retaining wall but with reference to the wall of the barn and that reference to the retaining wall was not required to define the boundary properly. He also referred to Watcham v The Attorney-General of the East Africa Protectorate [1919] AC 533, and said that if one considered the competing contentions of the boundary being (1) a straight line extension of the party wall or (2) the retaining wall and fence, it was difficult to see how, on a proper reading of the plan on the ground, the boundary could be said to be along the latter physical features rather than a cartographic line. He held that the retaining wall, not being present when the site plan was drawn, was no sort of conveyancing or identifying feature. He rejected a submission based on Ashton v Eastwood [1915] AC 912 that the ordinary competent person purchasing the property would treat the line of the retaining wall as the boundary, saying that when one looks at what the boundary connects with it was the edge of the house at the party wall, the plan showing a right angle where the boundary bisected the outside wall of the building. He also rejected a submission that no rational person could take as a boundary line the party wall, changing, as it did, at different levels throughout the house. He said that the rational person would look at where the wall fell at ground level. Looking objectively at the plan he saw the boundary properly defined in accordance with the plan and as asserted by the Beales. He found that the fence was misplaced, the boundary lying parallel with the boundary between Plots 2 and 3.

20. The Recorder accordingly granted a declaration that the Beales' line was the true line of the boundary between Plots 1 and 2 and an injunction restraining Mrs Harvey from obstructing the re-alignment of the fence. He ordered Mrs Harvey to pay the Beales damages in the sums of £750 for the costs of re-alignment of the fence and £200 for trespass. The Recorder refused permission to appeal, but permission was granted by Lord Justice Aldous.

21. On this appeal Mr Ball does not dispute that a mistake was made in that the wall and fence were not placed in the position shown on the site plan. Nevertheless he submits that that mistake does not affect the conveyancing position, as the Transfer to Mrs Harvey has to be interpreted by the features referred to on the plan as being the line of the boundary and existing on the ground at the time of the Transfer, that is to say that those features were the retaining wall and the fence. He argues that the position of the boundary is clear and would appear so to the ordinary reasonable purchaser going to the site with plan in hand. If that is not right, he submits that there was a latent ambiguity, that extrinsic evidence of what the parties subsequently did is admissible for resolving that ambiguity and that the conduct of Countrywide, through Mr Perkins, and of Mrs Harvey is consistent only with the conclusion that the boundary ran along the wall and fence. Mr Ball criticises the Recorder's finding that the Beales had purchased the disputed land to the north of the fence in view of the fact that the retaining wall and fence had been erected before the Beales made their purchase and that Mrs Harvey had turned the border area into part of her garden.

22. Finally he submitted that the Recorder was wrong to hold that estoppel had not been adequately pleaded.

23. Mr Treneer, for the Beales, submits that the Recorder was right to reach the conclusion which he did on all the points in issue. He argues that it was clearly material for the Recorder to consider the purpose for which the site plan was drawn. That, he says, was to show where the boundaries between the developed properties would fall and where retaining walls and fences and other yet to be constructed features on the ground were to be built in juxtaposition to the pre-existing features on the ground and in the buildings, which would not change on the carrying out of the development, such as the parapet and the dividing walls. He relies, in particular, on (1) the party wall on the line of which the boundary was shown as running for the length of the garden, (2) the plan showing the boundaries between Plots 1 and 2 and Plots 2 and 3 as parallel, and (3) the boundary line extending at right angles to the western wall of The Shippen as an extension to the party wall. He argues further that there was no pleading of estoppel, nor, if there was, of the type of estoppel and that a pleading of estoppel would have necessitated the joinder of Countrywide.

24. I start with the question of what was transferred to Mrs Harvey by the Transfer to her. That involves the construction of the parcels clause, the purpose of the exercise being to ascertain objectively what the parties must be taken to have intended and not what were the parties' subjective intentions. One notes from the Transfer to Mrs Harvey that the description of the property to be transferred is confined to what is shown edged red on the plan. That takes one to the plan. One notes that the boundary between Plots 1 and 2 is shown as a straight line running along the south edge of Phoenix Barn and the north edge of The Shippen and extending at right angles to The Shippen, east and west. One also notes that from the directions written on the plan it was intended that there should be a retaining wall and fence along the boundary line. However one can also note what the plan is, that is to say a reduced copy of an architect's site plan and that in 1998 when the plan was produced there would have been no retaining walls or fences on the ground. But it is right also to take note of the fact that at the time of the transfer there were both a retaining wall and a fence erected between Plots 1 and 2.

25. One then has to try to relate what the plan shows to the features on the ground. Although Mr Ball did not accept that it would be apparent on the ground that the retaining wall and fence did not accord with the plan, it is to my mind quite plain, as demonstrated by the photographs in evidence, that the line of the retaining wall and fence did not accord with the straight line shown on the plan. That is because one can see from the photographs that the line of the wall and fence is not on the line shown by the parapet. If one looked at the site from above, it would be even more apparent.

26. It is that discrepancy that gives rise to the problem. There are two possible arguments as to what was intended. One is that the line of the boundary was intended to run along the southern edge of Phoenix Barn and the northern edge of The Shippen where they joined, going eastward in a straight line to the estate road and westward in a continuation of that straight line to the mill stream, and that although the retaining wall and fence were intended to be on that boundary the placing of them on a different line is an error. The other is that the retaining wall and fence, both placed by Countrywide as intended to mark the boundary, did in fact mark the true boundary, the plan being inaccurate as showing a straight line extending from the estate road to the mill stream. Whichever indication is found not to represent the true intention of the parties falls to be rejected; in the old Latin phrase, it would be a falsa demonstratio (taken from the maxim falsa demonstratio non nocet). Mr Ball submitted that the latter was the correct interpretation, that the line of the retaining wall and fence was complete in itself and that it survived the error of the plan in showing the boundary as a straight line from estate road to mill stream. He said that the line of the wall and the fence would be apparent to any reasonable purchaser coming to the site who would automatically assume that that was the intended boundary. As for the point that the boundaries between Plots 1 and 2 and Plots 2 and 3 should be parallel, he said there was no evidence that the boundary between Plots 2 and 3 was visible on the ground at the material time of the transfer to Mrs Harvey, that the purchaser of Plot 1 would have no reason to concern himself with that boundary and that the developer who still retained Plots 2 and 3 could change his mind and alter the line of the boundary between Plots 2 and 3.

27. I have no hesitation in saying that the former construction must be correct. I say that for the following reasons. The property transferred was defined by reference only to what was shown edged red on the plan. As was said by Lord Justice Dillon in A J Dunning & Sons (Shopfitters) Ltd v Sykes & Son (Poole) Ltd [1987] Ch 287 at 299:

"The transfer is concerned to differentiate between three parcels of land ..... and it does so exclusively by reference to the plan on the transfer and the colouring on that plan ..... the colouring on the plan is thus the dominant description of each parcel ...... where parcels in a conveyancing document as described by reference to a plan attached to the documents, the natural inference is that it was the intention that anyone should see from the documents alone, which means from the plan on it what land the document was purporting to pass."

28. The dominant description, that is to say the red edging on the plan, must be given its full weight. It is to be noted that (1) that red edging is the single straight line that I have described, (2) that straight line west of the building accords with the plan showing the line to be at right angles to the east and west sides of The Shippen, and (3) that line accords with the plan showing that the straight line is parallel with the intended boundary between Plots 2 and 3. The fact that the retaining wall and the fence, although intended to be on the boundary line as the directions on the plan show, were built on a different line cannot be determinative of the true boundary. The erection of the retaining wall and fence on that different line seems to me to have been plainly an error, because it was inconsistent with what is shown as the straight red line on the plan. Further it would flout common sense to hold that, wherever Countrywide happened to build a retaining wall and fence, that must be the boundary regardless of the features of the plan to which I have drawn attention, even though at the time the plan was drawn the retaining wall and fence had not been erected and so the line of the red edging west of the buildings was not following existing features on the ground. Those accustomed to deal with conveyancing problems know only too well how frequently instructions on a plan are incorrectly carried out and buildings or fences or walls are put up in the wrong place. The difficulties for workmen trying to carry out instructions on a site plan are the greater where, as here, a wall or fence is to be erected on a featureless agricultural field. It would be absurd to attribute to the parties the intention that what was erected, however erroneously, subsequently to the preparation of the plan, should define the boundary, when the immutable feature at all material times of the line of the sides of Phoenix Barn and The Shippen where they joined was shown on the plan as part of the straight boundary line from the estate road to the millstream.

29. I have not obtained much assistance from Lyle v Richards because of its different facts. In that case the question was the true boundary of premises the subject of a lease. The lease described the southern boundary of those premises as "a straight line of about 355 fathoms from John Vincent's house ..... to a bound-stone", which was then described, the demised premises being "particularly delineated by the map", that map being on the back of the lease. The problem was this that the lease did not say from what part of the house that line was to be drawn. Further, on the map John Vincent's house had been placed incorrectly. The House of Lords held that extrinsic evidence was admissible to determine the true boundary. Lord Cranworth LC said at page 232:

"The map is referred to not for the purpose of shewing the site either of the house or the bound-stone. The facts as to the true position of the house and the bound-stone are ascertained by other means. The use of the map is to clear up what, without it, was uncertain, namely, from what part of the house the line was to be drawn; and for that purpose its exact site is immaterial."

Lord Cranworth said that it was for the jury, strictly, to say where the boundary line was drawn on the map, but because it was so plainly drawn from the north-east corner of John Vincent's house the jury would have had so to find. The problems which arose in that case differ from those of the present case. However, the Recorder, performing the function of the jury, had, in my view, to find, as he rightly did, where the boundary line ran.

30. As for the argument based on subsequent conduct, I confess that I find strange the notion that the true intention of the parties to Mrs Harvey's Transfer as to what they intended to be the boundary line between their properties should be ascertained by reference to what the parties did in the first few months after the Transfer at a time when it had not been pointed out, nor had it occurred to either of them, that the wall and fence had been wrongly positioned. The authority relied on by Mr Ball for the admissibility of such evidence is the Privy Council decision in Watcham . But Mr Ball did not take us to any of the many judicial and academic expressions of doubt about the correctness of that decision on that point. It is sufficient to refer to the remarks of two judges of great experience of real property law and to one text book. In Sussex Caravan Parks Ltd v Richardson [1961] 1 WLR 561 at page 568, Lord Justice Harman described Watcham as -

"a case which has been long under suspicion of the gravest kind from real property lawyers."

In Wickham Tools v Schuler AG [1974] AC 235 at page 261, Lord Wilberforce described Watcham as -

"a precedent which I had thought had long been recognised to be nothing but the refuge of the desperate."

He continued:

"Whether in its own field, namely that of interpretation of deeds relating to real property by reference to acts of possession, it retains any credibility in the face of powerful judicial criticism is not before us."

Watcham on this point runs counter to the decisions of the House of Lords that subsequent actions cannot legitimately be used to interpreet a written agreement (see John Miller & Partners v Whitworth Street Estates (Manchester) Ltd [1970] AC 572 and the Wickham case). In Chitty on Contracts 28th Edn (1999) at paragraph 12-124 note 36 the authors say of Watcham :

"The authority of this case is now extremely fragile."

A decision of the Privy Council is not binding on this court and I decline to follow it on this point.

31. For these reasons I would uphold the conclusion of the Recorder as to the true boundary between Plots 1 and 2 even though I, perhaps, diverge from some of his reasoning; but, in essence, in my judgment, he reached the right conclusion.

32. Mr Ball next argued that the property conveyed to the Beales was defined by the erroneously placed retaining wall and fence. He relied, in particular, on the fact that at the time of the Transfer to them anyone looking at what was on the ground would see not only that wall and fence but also the border which Mrs Harvey had planted. He said that in the circumstances the Transfer to the Beales should not be construed as including the disputed land north of the fence. I cannot agree. My reasons are essentially the same as those which I have given for determining that the true boundary between Plots 1 and 2 runs along the Beales' line. It is necessary to determine the true construction of the parcels clause in the Transfer to the Beales and, for reasons similar to those which I have given in relation to the Transfer to Mrs Harvey, it seems to me clear that the Beales did purchase the disputed land.

33. I turn finally to the estoppel point. Mr Ball submits that the material facts had been pleaded in paragraph 12 of the Defence and that the Recorder was wrong to prevent him from raising a case on estoppel as had been argued for in his skeleton put before the Recorder. Mr Treneer submitted in his skeleton argument that the Recorder was correct and had properly exercised his case management powers to exclude the late amendment.

34. The prior question is whether the Defence adequately pleaded an estoppel. By CPR 16.5 (1) the Defendant in his Defence must state which of the allegations in the particulars of claim he denies and by Rule 16.5 (2) must state his reasons for his denial. By paragraph 13.3 of the Part 16 Practice Direction the Defendant may refer in his Defence to any point of law on which his Defence is based, but he is not required do so. There is no requirement in the rules or in the Practice Direction that when pleading an estoppel, the Defendant must specify the type of estoppel on which he relies. In my judgment in the Defence the facts are adequately pleaded from which it was open to Mr Ball to argue that estoppel applied. I therefore, with respect, conclude that the Recorder was wrong to refuse Mrs Harvey the opportunity to put forward her estoppel case.

35. What then should follow? Should this case go back to the Recorder for a further trial limited to this point? Given that the facts relevant to this point are few and are not likely to occasion much dispute, and given the likelihood of yet further costs being added to those already incurred on this dispute, particularly if Countrywide were to be joined, I would be reluctant to remit the case. Both parties accepted that it would be right for this Court to determine the point. I think we should do so, assuming for this purpose that all the facts alleged by Mrs Harvey are true.

36. Mr Ball submitted that this is a case of proprietary estoppel. He agreed that Countrywide, by its conduct in placing the wall and fence on an incorrect line but intending them to mark the boundary and by consenting to Mrs Harvey expending time and money in planting a border up to the fence, could not have insisted on its strict legal rights because to do so would be inconsistent with Mrs Harvey's belief that the disputed land was conveyed to her. The equity thereby produced, he said, supported as it was by Mrs Harvey's occupation of the disputed land, was an overriding interest subject to which the Beales took. He relied, in particular, on the fact that Mr Beale had said in his witness statement that he had seen the fence between Plots 1 and 2 and that that had appeared to be the northern boundary of the garden for Plot 2.

37. It is now plain that the fundamental principle in relation to proprietary estoppel is that equity is concerned to prevent unconscionable conduct, and that while the element of detriment is an essential ingredient in proprietary estoppel, that requirement is to be approached as part of a broad inquiry as to whether the repudiation of a promise or representation could be unconscionable in all the circumstances, looking at the claim in the round (see Gillett v Holt [2001] Ch 210 and Jennings v Rice [2003] 1 FLR 501).

38. The following facts seem to me significant: (1) the placing of the retaining wall and fence on the wrong line was a mistake by Countrywide as it acknowledged; (2) the consent given by Mr Perkins to Mrs Harvey making a flower bed and planting plants and shrubs in the disputed land between February and April 1999 was no less a mistake; (3) as soon as the mistake was drawn to its attention Countrywide sought to correct it; (4) in its letter of 29 October 1999 Countrywide offered to bear all the expenses of re-alignment and disturbance; (5) Mrs Harvey was first aware that there was a problem as to the boundary in mid August 1999; (6) the disputed land amount to nearly one-eighth of the rear garden which was transferred to the Beales, but only amounts to less than one-twentieth of the garden of Mrs Harvey.

39. In my judgment, given the offer by Countrywide, the detriment suffered by Mrs Harvey by acting on Countrywide's promise or representation for so short a period is too insubstantial a detriment to make it unconscionable for Countrywide to seek to rectify its mistake at its own expense. Putting it another way, to treat what has occurred as giving Mrs Harvey the right to a permanent enlargement of her garden at the expense of the Beales with their smaller garden would be, in my view, quite disproportionate. No permanent or irremediable change in her garden had been effected by planting the shrubs and plants in the border. No reason has been suggested why what she planted could not have been moved quite easily after having been in the ground for only 6 to 8 months when Countrywide sought her consent. In all the circumstances therefore it seems to me that no proprietary estoppel such as would justify allowing Mrs Harvey to retain the disputed land has been made out.

40. I would therefore reject the estoppel Defence.

41. For all these reasons I would dismiss this appeal.

42. LADY JUSTICE HALE: I agree.

43. LORD JUSTICE RIX: also agree.

Order: Appeal dismissed with the costs as claimed by Mr and Mrs Beale to be assessed summarily.