Consideration of apportionment of the costs of any works
44The requirement to consider other possible causes of damage, under s 12(h)(i), and steps taken by the parties to prevent or rectify damage, under s 12(h)(ii), relates primarily here to determining who should pay the costs of any works, or how those costs should be apportioned.
45The Halls contend that, when water tanks were installed on the Stanfords' property in 2010, the ground was excavated, partly with a jackhammer. They say that this destabilised the wall and that the weight of the full water tanks has caused the wall to be displaced. They say that photographs show the tanks are against the wall. The Stanfords say that they had the tanks installed according to a council permit. They say there was no excavation, only that a garden bed that had been built up was removed back to the level of the original path, which remained. Any jackhammer works were to remove some of the concrete balcony footing, well away from the fence. They say the tanks were installed on a properly constructed 150 mm reinforced concrete base. They say the tanks are freestanding and were not against the wall when installed. I find the Stanfords' evidence and submissions regarding the tanks more convincing and more fitting of my observations at the site. There is no evidence that works for the tanks have destabilised the wall. If the wall is now against the tanks that is likely to be a result of its displacement. Displacement of the wall is most severe near the tree, not near the tanks. Most importantly, the wall's displacement was first brought to the Halls' attention five years prior to the tanks being installed. In my view the tanks are not a cause of damage to the wall.
46Several palm trees grow on the Halls' land to the east of the umbrella tree and close to the common boundary. No submissions regarding these palms were made by either party but I noted their proximity to the wall during the onsite view and mentioned this to the parties. In my view, due to the proximity of these palms to the wall, there is some likelihood that they have contributed to the wall's displacement, although I accept that the umbrella tree is the primary cause.
47Mr D. J. Hall's report suggested other factors may have contributed to the wall's displacement, but no evidence of this was provided and I do not accept those conclusions.
48When discussing factors that might be considered under s 12(h) of the Act, and particularly the phrase "anything, other than the tree, that has contributed, or is contributing...", Preston CJ in Robson v Leischke [2008] NSWLEC 152 said at paragraphs 206-207:
206The phrase also would include any act or omission by the owner of the land on which the tree is situated, which has contributed or is contributing to the damage or the likelihood of injury to any person.
207The considerations that arise in the tort of nuisance concerning fault, the nature of the conduct and the state of knowledge of a person on whose land a tree which causes a nuisance is situated (see discussion above at paragraphs 44-90), would be relevant in ascertaining whether any act or omission of that person has contributed or is contributing to the damage or injury. Thus, it would be relevant to consider whether the person created the nuisance constituted by the tree having caused, causing, or being likely to cause damage, or whether the person adopted or continued that nuisance. Such conduct could be said to be "anything, other than the tree, that has contributed, or is contributing to any such damage".
49The Halls were alerted to the Stanfords' concerns in the letter of 13 April 2005. Although the report obtained by the Halls soon after did not identify the tree as a cause, the report obtained by the Stanfords in July 2005 did identify the tree as a cause of the damage and recommended tree removal and repairs to the wall. The Halls, who received a copy of this report, were certainly aware of the likelihood that their tree was causing damage from July 2005. Furthermore, when questioned at the hearing by Mr Mitchell, Mr Hall stated that he was aware of the umbrella tree's presence from around 1986 and that, as a builder, he was also aware that tree roots could affect walls. Despite this, and despite Mr Drexler's report in 2005, the Halls maintained a denial of any responsibility through to 2011 and took no action. This "omission" to take action and "continuance of the nuisance" despite the Halls' "state of knowledge" are directly referred to above by Preston CJ as matters that should be considered.
50The Halls submitted that the Stanfords could have cut roots and repaired the fence. However, considering that the bulk of the root mass exerting pressure on the wall is located on the Halls' property I find this an unreasonable expectation. The Stanfords took what reasonable action they could by notifying the Halls. The responsibility then lay with the Halls.
51The report of Mr Moore in 2005 stated that the displacement of the wall was then 8 mm. It is not clear if the wall could simply have been repaired rather than replaced at that time, but certainly neither of the 2005 reports recommended demolition. Therefore the need for demolition and rebuilding, at greater expense, has most likely arisen as a consequence of the Halls' omission to take timely action.
52I am therefore of the view that, by contributing to damage through their omission, the Halls should be responsible for the primary costs of restoring the wall to its original condition.
53I accept that, if a new footing is required, the rebuilt wall will be an improvement on the original wall. It would therefore be reasonable for the Stanfords to contribute equally to this element, but only this element, of the new wall.
54The tree belongs to the Halls. The Stanfords have not contributed in any way to the need for its removal. The cost of tree removal will lie with the Halls.