Tree Preservation Orders (TPOs) continue to represent one of the most technically and legally complex intersections in property damage litigation. Recent developments—most notably the Upper Tribunal’s evolving approach to costs—signal a shift that practitioners, insurers, and local authorities ignore at their peril.
Tree root subsidence remains a classic form of private nuisance. Crucially, the actionable damage is not merely visible cracking, but the impairment of the load-bearing capacity of the soil, with structural damage to buildings arising as consequential loss. This distinction underpins both causation and the proper measure of loss, particularly where remedial works such as underpinning or root barriers are proposed.
In conventional nuisance claims, the legal framework is well established: claimants may pursue damages and/or injunctive relief requiring abatement. However, where the offending vegetation is protected by a TPO, that apparently straightforward analysis becomes significantly more complex.
TPOs impose statutory controls on works to protected trees, often placing environmental protection in direct tension with nuisance principles. Section 198(6) of the Town and Country Planning Act 1990 provides that TPO protection does not apply where works are “necessary… for the prevention or abatement of a nuisance”. Yet, as illustrated in Perrin v Northampton BC, “necessary” is not synonymous with “reasonably necessary”, and the availability of alternative solutions is relevant to the assessment.
This creates a practical dilemma. If works are undertaken without consent, there is a risk of unlawful interference. If consent is sought, it may be argued that the works were not “necessary” at all, because an application was made. In practice, and notwithstanding s.198(6), applications for consent to fell or prune are almost invariably required where TPO-protected vegetation is alleged to be causing subsidence damage.
Where a local authority refuses consent, or grants it subject to conditions, claimants may pursue compensation under:
Such claims are heard in the Upper Tribunal (Lands Chamber) and differ materially from civil litigation. They are not governed by the Civil Procedure Rules.
A compensation claim must be presented to the local authority within 12 months of the refusal, and any formal proceedings must be commenced in the Upper Tribunal within six years of the date the loss was sustained. Claimants must establish that the loss flows as a natural and probable consequence of the refusal, satisfies “but for” causation, and reflects reasonable mitigation—such as preventative engineering works.
Historically, a widespread (and frequently exploited) assumption has persisted that costs are not recoverable in the Upper Tribunal (Lands Chamber). The reality has always been more nuanced. The Tribunal enjoys wide costs powers under section 27 of the Tribunals, Courts and Enforcement Act 2007, supplemented by its procedural rules and practice directions.
Those powers extend to awarding costs in appropriate cases, particularly where claims involve injurious affection of land, or where conduct and offers justify such an order—often by analogy with Part 36 principles. However, a lack of consistent authority has historically generated uncertainty.
That uncertainty has now been materially reduced.
The recent Upper Tribunal decision in Royal Sun Alliance Insurance Ltd v London Borough of Harrow marks a significant development. The case concerned a subsidence claim linked to TPO-protected trees and a claim for statutory compensation. The Tribunal held that the claimant, Royal Sun Alliance Insurance Ltd, was entitled to recover its legal costs, and that London Borough of Harrow was required to pay those costs (subject to assessment).
This outcome is particularly notable given that the local authority continued to argue—despite settlement—that costs were not recoverable. The decision directly challenges the entrenched “no costs” orthodoxy and confirms that the Tribunal will exercise its discretion where justice requires it, without confining such awards to truly exceptional circumstances.
The implications are immediate and far-reaching:
Claimants are now able to advance credible arguments for full cost recovery, increasing the commercial viability of statutory compensation claims and encouraging earlier, more pragmatic settlement decisions.
TPO subsidence claims are won at the intersection of engineering evidence and legal precision. The key practical message for practitioners is clear: outdated assumptions on costs should no longer deter the pursuit of well-founded compensation claims. Early investment in expert causation evidence and careful strategic framing remain critical.
TPO-related subsidence disputes have long sat at the crossroads of environmental protection, private property rights, and technical causation. What RSA v Harrow demonstrates is that the landscape is evolving—most notably on costs.
For claimants, the path is clearer.
For defendants, the risks are sharper
.For practitioners, the message is simple:
Costs are back in play—and they may now be the most important battleground of all.
If you have any questions on this topic, please get in touch.
Jessica Taylor - Associate and Subsidence & Vegetation Special Interest Group member
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