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Do all basement extensions require planning permission?

Earlier this month, a court decided that a basement extension could not be lawfully carried out using permitted development rights.  There is now concern that the decision in Eatherley v London Borough of Camden could prevent the use of permitted development rights for basement extensions. So does this decision mean that all basement extensions now require planning permission?

What are permitted development rights?

If a type of development benefits from permitted development rights, it means that it is, in effect, granted planning permission without having to apply for it. Whilst there is no specific provision for basement extensions in the Town and Country Planning (General Permitted Development) (England) Order 2015, most local planning authorities have treated basement developments as permitted development.

The decision

The decision centred around whether the engineering works, which were a necessary part of the basement development, were part of the development, or were a separate activity. The distinction was critical:

  • If they were part of the basement development, permitted development rights would apply.
  • If they were not, whilst the basement extension may benefit from permitted development rights, the associated engineering works would not. Therefore, planning permission would be required for those engineering works.

The court decided that the local planning authority had asked itself the wrong question when making its decision to grant a lawful development certificate.

Rather than asking whether the engineering works were part and parcel of the making of a basement, the local planning authority should have asked whether the works constituted a separate activity of substance.

To assess this, the local planning authority would have needed to examine the nature of the excavation and removal of the ground and soil, and the works of structural support required. Only after looking at these elements could it decide whether the works amounted to a separate activity of substance, for which planning permission would be required.

Will all basement extensions require planning permission?

It is difficult to see how any basement development could be undertaken without significant engineering works.

The court in this case did not say that engineering works would always constitute a separate activity of substance; it merely decided that the local planning authority had asked itself the wrong question and had not, therefore, looked into the issue sufficiently.

Nevertheless, some have commented that the decision belittles permitted development rights. It remains to be seen whether the decision will be appealed.

Even without an appeal, there are complexities around basement developments.

  • It is open to a local planning authority to make an Article 4 direction, withdrawing permitted development rights, so that an application for planning permission has to be made.

    An Article 4 direction can only be made in exceptional circumstances. The effect of this is to restrict or withdraw permitted development rights. If permitted development rights are withdrawn, it means that planning permission has to be sought.

    For example, this is what Camden Council did on 3 October 2016. This means that from 1 June 2017 planning permission will be required for basement developments in the London Borough of Camden. Other local planning authorities have also taken measures to curb basement developments.
  • In acknowledgment of the concerns surrounding basement developments, the government is reviewing the planning law and regulations which relate to basement developments. As part of this review, it is seeking the views of those who have experience of, or have been affected by, basement developments. Evidence must be submitted by Friday 16 December 2016. For further information read Basement Developments and the Planning System – Call for Evidence

Given the conditions that have to be met, the various policies that may exist, and the possibility of an Article 4 direction being in place, together with the uncertainty that exists following the decision in Eatherley v London Borough of Camden, and possible changes to the law following the government's review, advice should always be sought from a qualified planning lawyer before embarking on any subterranean development works.

Contributor: Alexandra Holsgrove Jones

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at December 2016. Specific advice should be sought for specific cases. For more information see our terms & conditions.


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