Permitted Development in London: Complete Guide for Homeowners

Permitted Development rights are a national grant of planning permission for certain classes of development, set out in the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). They apply automatically to eligible properties — you do not need to apply for planning permission for works that fall within PD rights, provided the works meet all the conditions and limitations for the relevant class. PD rights are not unlimited — each class has specific size limits, height limits, material conditions, and other requirements that must all be met for PD to apply. If any single condition is not met, the works fall outside PD and planning permission is required. PD rights can also be removed or restricted by: Article 4 directions (issued by the local planning authority to remove specific PD rights in an area — very common in London conservation areas); planning conditions attached to the original planning permission when the house was built or extended; the property being a listed building (PD rights do not apply to listed buildings); the property being a flat or maisonette (PD rights for external alterations do not apply to flats); or the works being in a class where PD applies only to houses and not flats.

The most commonly used PD class for London homeowners is Class A — extensions to a dwelling house. For a single-storey rear extension in London, the key PD conditions are: the extension must not extend beyond the rear wall of the original house by more than 4m (for a detached house) or 3m (for any other house, including terrace and semi-detached); the height of the extension must not exceed 4m; the extension must not extend beyond the side elevation of the original house; the materials must be similar in appearance to those of the existing house; the extension must not exceed half the area of the original garden. Under the Neighbour Consultation Scheme (Prior Approval), the depth limit is extended to 6m for terraced/semi houses and 8m for detached houses, subject to a 42-day consultation with neighbours. The Neighbour Consultation Scheme requires a prior approval application to the local authority (currently free of charge), a 42-day consultation period, and confirmation of prior approval before works start. For two-storey rear extensions, PD rights are much more restrictive — the extension must not exceed 3m beyond the rear wall of the original house, and must be at least 7m from the rear boundary.

Loft conversions are covered by Class B of the GPDO. Key conditions: the additional roof space created must not exceed 40m3 for terraced houses or 50m3 for detached and semi-detached houses; the conversion must not include any addition to the front roof slope (visible from the highway); the height of the roof must not be increased; the materials of the addition must be similar to those of the existing house; and any dormer windows on a side roof slope must be obscure-glazed and non-opening below 1.7m. These limits mean that a typical rear dormer on a London terrace (within 40m3) is usually within PD, but a large Mansard conversion or a hip-to-gable conversion may exceed the volume limit. A Certificate of Lawful Development is strongly recommended for loft conversions near the volume limit to confirm PD applies.

Class E covers outbuildings, garages, and garden structures ancillary to the house. Key conditions: the structure must be in the rear garden (not in front of the principal elevation); it must be single-storey; the maximum height is 2.5m if within 2m of the boundary, or 4m (dual pitch) or 3m (other) if further; the total area of outbuildings must not exceed 50% of the total original garden area; and the structure must be incidental to the enjoyment of the house (not a separate dwelling). This class covers garden offices, garden studios, summerhouses, and similar structures. In conservation areas, Class E outbuildings on the side of the house visible from a highway require planning permission. PD rights for outbuildings do not apply to listed buildings. A separate class (Class G) covers additions like satellite dishes and solar panels, with their own conditions.

London has over 1,000 conservation areas, and many London boroughs have issued Article 4 directions removing specific PD rights within those areas and beyond. The most common PD rights removed in London conservation areas are: the right to install replacement windows and doors visible from the highway (most London conservation areas); the right to add satellite dishes visible from the highway; the right to add outbuildings in the side garden visible from the highway; and (in some boroughs) the right to build rear extensions visible from the highway. Some London boroughs (Kensington and Chelsea, Westminster, Camden, Islington, Hackney) have extensive Article 4 directions that remove very significant PD rights across large areas outside conservation areas. Before assuming PD applies to any works in London, check: is the property in a conservation area? Does an Article 4 direction affect the property and the specific class of works? Is the property subject to any planning conditions from previous planning permissions that restrict PD? The definitive way to confirm PD applies is to apply for a Certificate of Lawful Development (CLD) — this is a formal council confirmation that the proposed works are lawful under PD, and provides legal certainty.