Hampstead Architecture and Planning

Conservation · Planning

Trees, TPOs and Conservation Areas: What You Can and Cannot Do

A protected tree can shape — or stop — a London home project, and unauthorised work is a criminal offence. This guide explains Tree Preservation Orders, the notice you must give for trees in a conservation area, and what it means for extensions and basements.

Last updated 5 min read

Why trees matter for a home project

Trees are easy to overlook when planning an extension, a basement or a garden building, but they can be one of the most decisive constraints. A protected tree near the works can limit where and how you build — because of its roots as much as its canopy — and cutting or damaging one without consent is a criminal offence. Two forms of protection matter in London: Tree Preservation Orders, and the protection that applies to trees in conservation areas.

Tree Preservation Orders (TPOs)

A Tree Preservation Order is made by the council to protect a specific tree, group of trees or woodland in the interests of amenity. Where a tree is covered by a TPO, you need the council’s written consent to cut it down, top, lop, uproot, or wilfully damage or destroy it. Carrying out those works without consent is an offence, and the fines can be substantial. If you are not sure whether a tree is protected, the council can tell you — and it is always worth asking before any work.

Trees in a conservation area

In a conservation area, trees are protected even without a TPO. You must give the council six weeks’ written notice — a "section 211 notice" — before carrying out work on a tree whose trunk is more than 75mm in diameter, measured at 1.5 metres above the ground (or more than 100mm if you are thinning to help other trees grow). The notice gives the council the chance to make a Tree Preservation Order if the tree merits it. If it does not, you may carry out the proposed work, and you then have two years from the notice in which to do so.

Dead, dying or dangerous trees

There is a limited exception for dead trees and those that pose a danger, but it is narrower than people assume. Unless the work is urgently necessary because of an immediate risk of serious harm, you must still give the council five working days’ written notice before cutting down or working on a dead tree. Removing a tree on the assumption that it is dead or dangerous, without evidence and without notice, is a common and costly mistake.

What it means for your project

The practical point is to establish the tree position early — before the design is fixed. A protected tree does not necessarily prevent an extension or basement, but its root protection area and canopy have to be designed around, often with an arboricultural report supporting the planning application. Identifying this at feasibility avoids a design that cannot be built, and a programme delayed by a notice period or a consent you did not know you needed.

Frequently asked questions

Do I need permission to cut down a tree in my garden?

If the tree is covered by a Tree Preservation Order, yes — you need the council’s consent to fell, top, lop or damage it. If it is in a conservation area, you must give the council six weeks’ notice first. Outside those, a garden tree can usually be worked on without permission, but it is worth checking its status.

What are the rules for trees in a conservation area?

You must give the council six weeks’ written notice before working on a tree with a trunk more than 75mm in diameter (measured at 1.5 metres), or more than 100mm if thinning. The council can make a Tree Preservation Order in that time; if it does not, you have two years to carry out the work.

What size of tree is protected in a conservation area?

The notice requirement applies to trees with a trunk diameter over 75mm measured at 1.5 metres above ground level, or over 100mm where the work is thinning to benefit other trees.

What is the penalty for cutting down a protected tree?

Carrying out unauthorised work to a tree protected by a Tree Preservation Order, or in a conservation area, is a criminal offence and can attract substantial fines. Always confirm a tree’s status before any work.

Can I remove a dead or dangerous tree without permission?

Only in limited circumstances. Unless the work is urgently necessary because of an immediate risk of serious harm, you must still give the council five working days’ notice before working on a dead tree.

Can a protected tree stop my extension or basement?

Not necessarily, but its roots and canopy must be designed around, often with an arboricultural report supporting the application. Identifying protected trees early avoids a design that cannot be built.

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