DAMAGES
146The owners rely on a report by Mr Haslam of Northcroft dated 10 May 2013 which assessed costs for retaining walls, drainage and consequential loss. Mr Haslam also prepared a supplementary report dated 24 May 2013.
147I accept Mr Haslam as a quantity surveyor, with substantial experience in the building industry. There was no challenge to his standing as an expert.
148At paragraph 2.3.2 of his report Mr Haslam states that he undertook a measurement of the scope of work from the design documentation provided by Mr Dockrill and from site measurements undertaken during his site inspection.
149Mr Dockrill's 10 May 2013 report at paragraph 4 sets out the rectification works that he says are required. They are shown on his drawing C-02 attached to his report. Drawing C-01 to Mr Dockrill's report indicates that a retaining wall is to be built to retain the southern embankment opposite the entire length of the premises, including the southern wall of the garage. Mr Dockrill designs this retaining wall as being in two parts, retaining wall type 1 and retaining wall type 2.
150Mr Haslam's report dated 10 May 2013 contains a total costs assessment of $95,968.00 inclusive of GST.
151Mr Barnett gave evidence on behalf of the builder of the cost to construct a retaining wall approximately 10 metres in length. There was no challenge to his standing as an expert. Mr Barnett prepared a report dated 18 January 2013 which was exhibit 4 in which he estimated the cost of the retaining wall to be $10,691.95, excluding GST, preliminaries and margin. I regard Mr Barnett's estimate to be simplistic.
152Mr Haslam's supplementary report dated 24 May 2013 responds to Mr Barnett's report. Mr Haslam assesses the cost of constructing a retaining wall, on the basis of the builder's scope of work, plus rectification of consequential damage with allowances for overheads, margins and GST at $47,772.00.
153During the course of the hearing I raised questions about the necessity for a retaining wall to be constructed to retain the southern embankment opposite the entire length of the premises, including the southern wall of the garage, rather than only opposite the southern wall of the garage.
154During final submissions the owners handed up a document titled Retaining Wall Volumes. This document assessed retaining wall works to be $50,364.00, consequential damage works to be $4,027.56 giving a total of $54, 391.56 to which preliminaries, and overhead and margin of 15% was to be added with GST to be added to the total.
155Orders were made to allow the builder to respond to this document. The owner was given a right of reply. Both parties filed and served submissions in accordance with these orders.
156The major item of disagreement between the parties is the length of the retaining wall. The owners' experts contend that a 20 metre retaining wall is required. The builder's expert contends that a 10 metre retaining wall is required.
157The basis for the owners' position is retaining wall type 1 on drawing C-01 to Mr Dockrill's report and the retaining wall shown on the Barker Harle drawing 20257. The owners conceded in their submissions dated 19 December 2013 that the walls depicted in both drawings are of a total length of 20 metres. The retaining type 1 does not run the full length of the southern boundary of the property. However it does extend in either direction past the ends of the southern wall of the garage.
158Mr Barnett's report comments briefly on the issue of retaining walls. Mr Barnett is not an engineer. Mr Barnett has, as explained above, prepared a costing based on a 10 metre retaining wall.
159If the relevant expert had produced cogent reasons to justify the length of the retaining walls referred to in their reports or drawings, the Tribunal would be in a position to analyse the reasoning to justify the wall of the length the expert says is appropriate.
160Unfortunately, there is no such reasoning in Mr Dockrill's reports. His drawing C-O1 refers to walls type 1 and 2, yet his report, so far as I can ascertain, does not discuss the reasoning behind the design lengths of the two walls and in particular retaining wall type 1. There is no explanation in Mr Barnett's report about why he has concluded that a retaining wall 10 metres in length would be adequate or sufficient if the Tribunal were to find in the owners' favour. Mr Henderson in his reports which are in exhibit 7 does not offer an opinion about the appropriate length of a retaining wall, if an order was to be made by the Tribunal in favour of the owners on the retaining wall issue. Mr Storr in his report dated 19 April 2012 makes a recommendation that 'the embankment adjacent to the garage area and to the south be retained by the provision of a reinforced masonry block wall'.
161Mt Storr's drawing 20275 dated 18 June 2012 was obviously provided after the date of his report. It shows a retaining wall adjacent to the garage area and extending both to the right and left of the garage. The developed elevation on drawing 20275 shows the wall stepping down, presumably at the exterior edges of the garage and including a return of 0.600 metres.
162The decision that I must make despite the absence of reasoning about the length of retaining walls, is whether I prefer the owners' or the builder's evidence. I have decided that the owners' evidence which is that of Mr Dockrill in connection with the type 1 wall, which is almost identical to Mr Storr's design, is to be preferred. The reason for coming to this decision is that both Mr Dockrill and Mr Storr are engineers whereas Mr Barnett does not possess that qualification. As submitted by the owners counsel, Mr Barnett has not provided design drawings in relation to the wall that he has costed. In my view it is appropriate to act on the evidence of experienced engineers in connection with the issue of the appropriate length of the retaining wall.
163The next issue to be decided in connection with damages is the costing of the retaining wall that is to be preferred. I have set out above the competing reports as regards costing. I prefer the costing carried out by Mr Haslam to Mr Barnett's costing. At paragraph 9 of the owners' counsel's submissions a number of matters conceded by Mr Barnett were set out. I accept that those matters conceded by Mr Barnett make it unsafe to accept his cost assessment as regards retaining walls. There is also the fact of Mr Haslam's comments on Mr Barnett's report dated 24 May 2014 as contained in section 4 of his report e.g. paragraphs 4.3.5, 4.3.6, 4.3.7 and in paragraph 7.1.7 of his Conclusion, all of which I accept.
164As stated, during final submissions the owners handed up a document titled Retaining Wall Volumes. This document valued retaining wall works at $50,364.00, consequential damage works at $4,027.56 giving a total of $54,391.56 to which preliminaries, overhead and margin of 15% was to be added, with GST to be added to the total.
165The Retaining Wall Volumes document is based on the calculations in Mr Haslam's 10 May 2013 report. The amount claimed for a number of items has been reduced to 71.8% of the amount originally claimed. The reduction was made to reflect an assessment, in the case excavation and other marked items, of the work associated with a retaining wall type 1 of 20 metres.
166The builder has made submissions about the owners' Retaining Wall Volumes. The builder's submissions relate to items 10 and 12 of the Retaining Wall Volumes document, which items relate to excavation. The builder criticizes the figure of 71.8% and states that in some cases it ought properly be reduced to 54%. This would have the effect of reducing the damages total.
167In their reply submissions the owners concede the builder's criticism, but state that the correct percentage is 61.3%. The owners' state that the quantities for excavation ought to be ascertained by footing dimension, and state that the footing dimension for type 1 walls are wider than the footing dimension for type 2 walls. The Dockrill drawing CO-1 establishes that the type 1 wall footing dimension is 1.17m x .150 as submitted by the owners.
168I accept that the owners should recover 61.3% of items 10 and 12 of the Retaining Wall Volumes document as summited by their counsel.
169The builder in his submissions next attacks items 13, 32, 33 and 34 on the basis that these items have no correlation to wall areas. The owners have reduced the recovery percentage for these items to 71.8%. I reject the builder's criticism. The cost estimate has been amended to reduce these items on the basis that the only work that they relate to is retaining wall type 1. This in effect reduces the quantities for this work which, in my view, is a proper basis for estimating the cost of work.
170Next, the builder next attacks items 1, 2, 3, 4, 5, 6, 21, 24 and 26 on the basis that it is not clear which of these items would be required as the plans would require substantial amendment for a shorter wall. The builder does not address what changes would or may be required. Plan CO-1 most clearly identifies wall type 1 and importantly provides a detailed section of retaining wall type 1. The plan is revision C which the plan notes has been re-issued for pricing. However it seems to me that the plan may require amendment, at least in connection with drainage.
171The owners' response states that all items and the services that are referred to would be required apart from the sewer services in items 2 and 5. I will delete items 2 and 5 from the Retaining Wall Volumes document, when recalculating the totals.
172In considering the builder's submissions on items 1, 2, 3, 4, 5, 6, 21, 24 and 26, I have come to the conclusion that items 1, 3, 4, and 6 relate to the totality of the 37 metres retaining wall length, rather than a retaining wall of 20 metres in length. Accordingly I find that owners' recovery in connection with these items should be reduced to 71.8%.
173I have made the necessary adjustments to the Retaining Wall Volumes document.
174In considering the issue of damages I am conscious of the fact that the parties were not in a position to consider this issue and make submissions after they had the opportunity of considering these reasons for decisions. With the benefit of hindsight, it may have been the best course to have considered damages after findings on liability were made. In particular, it is not clear how the quantum evidence can accommodate my findings that the owners are precluded from making claims concerning drainage at the left hand, garage side, of the premises. It is also not clear which items in the owners' quantum evidence relate to the issue of the grading of the site to enable drainage of surface water away from the garage entrance. I will address these concerns in paragraphs 175 - 181.
175So far as drainage is concerned, I note that at item 17 of the Retaining Wall Volumes document, a concrete dish drain is claimed for. The claim is for 74 metres of dish drain at $37.00 per metre. The results of my findings are that a 20 metre retaining wall is allowed for with associated drainage. I note in drawing C-01 that dish drains are shown at the top and bottom of the retaining wall. It follows that retaining wall type 1 will require dish drains of 40 metres. The drawing also shows the dish drains extending to the west side of the property to connect with the drainage as depicted on that side of the premises. In that case the 17 metre dish drain at the foot of the wall will be required, but the 17 metre dish drain depicted at the top of retaining wall type 2 will not be required. As a result, I will reduce item 17 to $2,109.00 (57 metres x $37.00).
176Also in connection with drainage, Mr Haslam states at 2.3.2 of his report that he measured the scope of work from design documentation provided by Mr Dockrill.
177Mr Dockrill's drawing C-01 refers to the following work to be carried out to the left hand or garage side of the premises:
(a)150 mm PVC pipe connected to end of inline pit;
(b)Inline pit;
(c)Corner connections; and
(d)New 'reln storm masta class B grated drain along front edge of existing garage'.
178As a result of my findings under the Allianz v Waterbrook heading, the owners are precluded from claiming and recovering for this work. There needs to be adjustments to the Retaining Wall Volumes document to ensure that these costs are removed from the amount to be found in the owner's favour.
179In connection with the 150 mm PVC pipe, I note that drawing C-01 specifies 150 mm PVC pipe in two locations. I estimate that 25% of the allowance of 17 metres in item 26 relates to the left hand or garage side of the premises. I will therefore reduce item 26 to $459.00.
180In connection with the Inline pit, I will delete item 21 which is for that item.
181In connection with New 'reln storm masta class B grated drain along front edge of existing garage' I will delete item 20 which is for that item and also item 18 which relates to that item.
182The owners also claim for consequential damage which relates to the cost of rectifying water ingress damage to the garage. They claim $4,027.56 for the necessary work which is calculated by Mr Haslam in 11 items in his report under the heading 'Consequential Damage'. Mr Capone at paragraph 16 of his 7 November 2012 statement describes the damage to the internal linings of the garage. He annexes a quote dated 5 November 2012 where a builder provides a quote in the sum of $4000.00 to carry out repair work. I accept Mr Capone's evidence describing the damage to the internal linings of the garage. I also accept that such damage arises by reason of the breaches of the statutory warranties that I have referred to.
183Mr Barnett has dealt with this subject on page 11 of his 18 January 2013 report under the heading 'Rectification'. He allows for cleaning of plasterboard and application of two coats of acrylic paint to plasterboard. The total he allows for these items is $375.00.
184I prefer the evidence of Mr Haslam to Mr Barnett's evidence on the subject of the rectification of the internal linings of the garage. Mr Haslam's cost breakdown is more thorough and is supported by the quotation which is at annexure L of Mr Capone's statement.
185I will therefore find in the owners favour in the sum of $4,027.56 as the cost of the rectification of the internal linings of the garage.
186The total cost of constructing the retaining wall, including associated stormwater and consequential damage as discussed above is therefore $65,716.57 representing a base cost of $47,227.15 plus preliminaries of 10%, plus overhead and margin of 15% on the base cost and preliminaries, with GST of 10% added.
187The damages may be broken down as follows:
Retaining walls excluding, stormwater $41,207.59
Stormwater $1,992.00
Consequential damage $4,027.56
Total $47,227.15