UK Planning Permission Guide

Single-storey rear extensions are often Permitted Development within size limits. Larger extensions, side extensions on terraced houses and two-storey additions usually need Full Planning Permission.

Adding roof space within the PD volume limit is usually allowed without planning permission. Front-facing dormers and hip-to-gable conversions on terraced houses typically need Full PP.

Converting an integral or attached garage to living space is usually Permitted Development. Blocking in the garage door with matching materials is generally acceptable without a planning application.

Conservatories are treated as extensions for planning purposes. They are Permitted Development within the same size and height limits as a standard rear extension.

Garden studios and home offices are usually Permitted Development provided they remain single-storey, cover less than 50% of the garden, and are not used as a separate self-contained dwelling.

Sheds, garages and timber outbuildings are usually Permitted Development. Height limits apply - 2.5m maximum if the building is within 2m of a boundary.

A new front porch is Permitted Development provided it is under 3m² ground floor area, no taller than 3m, and not within 2m of a public highway or footpath open to vehicles.

Rear dormers and roof lights are usually Permitted Development. Any dormer on the front (principal) elevation facing a highway always requires Full Planning Permission.

An outdoor swimming pool is usually Permitted Development if it sits within the outbuilding rules - covering no more than 50% of the curtilage and not forward of the principal elevation.

Fences and walls up to 1m on a boundary adjacent to a highway, or 2m elsewhere, are Permitted Development. Anything higher needs Full Planning Permission.

A driveway using permeable surfaces such as gravel or permeable block paving is Permitted Development. Non-permeable surfaces over 5m² require Planning Permission to manage surface water run-off.

Roof-mounted solar panels are usually Permitted Development provided they do not protrude more than 200mm from the roof surface. Listed buildings and conservation areas have additional restrictions.

Changing a building's use - from commercial to residential, agricultural to dwelling, or to a House in Multiple Occupation - almost always requires a formal planning application or Prior Approval.

Converting an existing basement to habitable space is usually Permitted Development if there are no material external changes. Excavating a new basement or adding a lightwell to the front may require Full PP.

An annex within or attached to the main house may be Permitted Development. A detached structure with its own entrance, kitchen and bathroom is likely to be treated as a new dwelling requiring Full Planning Permission.