UKHL 55
Where there is a continuing nuisance, which a defendant knows about or ought to know about, the claimant is entitled to the reasonable costs of eliminating the nuisance if he has given notice of the problem to the defendant and a reasonable opportunity to deal with it.
The council refused to remove a mature plane tree that was causing damage to a building. The claimant therefore spent over £570,000 carrying out underpinning works and claimed the cost from the council.
The HL held the council liable for that sum. The claimant was not merely entitled to damages for the damage to the property that had occurred during its period of ownership. If the tree had been removed the need to underpin would have been avoided and the total cost of repair to the building would have been only about £14,000!
Normal rules apply
 EWHC 2257 (TCC)
A house had been damaged by tree roots. The court held that the owner of the trees was responsible for the damage due to a defective pruning regime. Tree root cases are not subject to any special principles but are governed by the law of negligence and nuisance.
A house owned by O had suffered cracking and other damage due to the roots of trees owned by a local authority (L). Although all possible causes of subsidence were known, it was very difficult to work out which cause was the most likely. O claimed damages against L. Edwards-Stuart J, said:
- “This is one of those cases where the court must choose between one or more of a limited number of potential identified causes – in this case the various species of tree: as the experts have agreed, it is not a case where there might be unknown causes. Of the known potential causes, the court must choose as the most probable cause the candidate (or candidates) that is the least unlikely”.
Ultimately the court found that L had actual knowledge that certain poplar trees of L could cause damage due to previous claims in the street.
The court found for O. The court had to consider what action L should have taken based on its knowledge and held that L had failed to implement a reasonable cyclical pruning programme in accordance with prevailing practice. Had they done so the significant damage to the property could have been prevented.
It was therefore for L to show that to show that even if it had acted with reasonable care by doing the pruning works the damage would probably still have occurred (see Phethean-Hubble v Coles  EWCA Civ 349). However, as to this Edwards-Stuart J, said:
- “Since the Council has advanced no evidence as to what it would have done (unsurprisingly, since its case is that it was not obliged to do anything), it must necessarily be unable to show that the damage would have occurred in any event”.
This case was complicated due to difficulties concerning expert evidence in relation to the tree root damage. See also Berent v Family Mosaic Housing  EWCA Civ 961 which made it clear that tree root cases are not subject to any special principles of law but are governed by the general law of negligence and nuisance - judgment in this case was delayed pending the outcome of that Court of Appeal decision.
Tree root encroachment - damages claim - need to give notice?
 EWCA Civ 1701
To establish a cause of action for damages it is not necessary to show that notice has been given before works are undertaken to remedy damage caused by nuisance.
C carried out underpinning work, at its own (substantial) expense 1999, to remedy subsidence allegedly caused by the encroachment of tree roots for which the council was responsible. No complaint was made to the council at that time. The council was not expressly notified of this until 2003. When further damage occurred in later years C made a claim against the council, which argued that the failure to notify the council of the problem in 1999 made it a knock-out point which makes it plain that the claim in respect of No 42 could not succeed at trial. The judge struck out the claim because of the lack of notice.
Decision on appeal
However on appeal the CA said that this was wrong and the matter should go to trial. Pill LJ:
"I do not accept the proposition advanced by Mr Makey, in seeking to uphold the striking out of the action by the judge, that, as a matter of law, where nuisance is created by tree roots there is no liability for resulting damage, unless and until damage has been notified to the tortfeasor. In my judgment, that proposition does not emerge from [Delaware Mansions v Westminster City Council  UKHL 55]. Thereafter, what can be recovered by an injured landowner is a different question, and it was that question which was considered in Delaware." (para 37)
Tree roots - sufficient degree of control
LE Jones (Insurance Brokers) Ltd v Portsmouth City Council
 EWCA Civ 1723
Hampshire County Council owned the land upon which the offending trees stood. However, the defendants, Portsmouth CC, maintained it under an agency agreement that included the routine maintenance of the trees. They failed to maintain the trees, which led to soil desiccation, which led to damage to Cs property.
The defendants had a sufficient degree of control over the hazard causing the nuisance, even though they did not own or occupy the land, to make them liable for the nuisance.