The recent high court case of Eatherley-v-London Borough of Camden and Another at the end of 2016 has made changes about whether planning permission is required for residential basement developments.  Prior to this case it was usual, in certain circumstances, for a developer to rely on Permitted Development Rights* (“PDR”) rather than having to make an application for planning permission.  To rely on PDR the development works have to fall within the classes of development described in the General Permitted Development Order (“GPDO”) and the development must be within the curtilage of a dwelling house.

There has recently been a lot of bad press about significant basement excavations in London and this may be a reason why there is now more litigation on this issue. The judge in the above case decided that in the context of an original “two up two down” terraced house in suburban London, the new development of a basement (where previously there was none) could amount to two activities, each of substance:

• The enlargement, improvement and alteration of a dwelling house
• An engineering aspect of excavating a space and supporting the house and its neighbours

In the present case the court found that the engineering operation was necessary to achieve the developer’s aim, and was indivisible from it, there was a “separate activity of substance” and therefore express planning permission would be required from the local planning authority.

In light of the above it appears that it is a matter of fact and dependent on the degree of the works and, whilst PDR has the effect of granting planning permission for the enlargement, improvement and alteration of a dwelling house, it does not provide permission for any engineering aspect.

If you are considering carrying out excavation works to create a basement, you should ensure that your architect, surveyor and builders are fully up to date with this recent high court decision. 

* (under Class A, Part 1, Schedule 2 to the GPDO 2015)