A porch provides a useful weather-protected entrance and can add character to the front of a house. Many porches fall within the specific permitted development rules that apply to front porches, allowing them to be built without a planning application, but the conditions must be checked carefully.

The Permitted Development Rules for Porches

Under Class D of Part 1 of the General Permitted Development Order, a porch is permitted development and does not require planning permission provided three conditions are all met. The ground floor area of the porch, measured externally, must not exceed three square metres. The height of the porch must not exceed three metres above ground level at any point. No part of the porch must be within two metres of the boundary of the curtilage where it adjoins a highway.

These three conditions define the scope of the porch permitted development right. A porch within three square metres on plan, under three metres in height, and set at least two metres from a road boundary can be built without planning permission on most residential properties.

When Planning Permission Is Required

Planning permission is required for a porch that exceeds any of the three permitted development conditions: larger than three square metres, higher than three metres, or within two metres of a highway boundary. Planning permission is also required for porches on flats and maisonettes, and for any porch on a listed building. In conservation areas, the same conditions apply for permitted development porches, but the design should be sympathetic to the character of the area and conservation officers may comment if an application is required.

Permitted Development Applies to Flats?

The Class D porch permitted development right applies only to dwellinghouses, not to flats or maisonettes. A flat owner who wishes to add a porch to their front entrance, if that is even structurally and tenure-wise possible, would require planning permission regardless of size.

Building Regulations

A porch under 30 square metres that is at ground level and has no sleeping accommodation may be exempt from Building Regulations if it is unheated. A heated porch, a porch with electrical installations, or a porch that is integrated with the house's thermal envelope rather than separated by an external-quality door may trigger Building Regulations requirements. Electrical work in a porch requires Part P compliance in all cases.

Summary

A porch up to three square metres in area, under three metres in height, and at least two metres from a highway boundary is permitted development and does not require planning permission for most dwellinghouses in England. Larger, taller, or poorly positioned porches require planning permission, as do all porches on listed buildings and any porches on flats. Building Regulations may apply to heated porches and to electrical installations.