Does a loft conversion always count as permitted development?

Only if it stays within the GPDO Class B limits for depth, height and boundary distance, the property isn't in an area with an Article 4 direction removing those rights, and less than 50% of the curtilage is already covered by extensions or outbuildings.

What if my property is in a conservation area?

Conservation area status tightens several permitted development limits, particularly for side extensions and roof work facing a highway. Use the checker below with your postcode - it flags conservation areas automatically.

Do side-facing windows need special treatment?

Yes — side-facing windows must be obscure-glazed and non-opening below 1.7m from the floor.

Planning permission for a loft conversion on a terraced house

Under GPDO 2015 Schedule 2, Class B, many loft conversion projects on a terraced house qualify as permitted development if they stay within set limits. Enter your postcode and dimensions below for a verdict specific to your address.

Permitted Development & Cost Checker

England only. Takes about a minute.

Permitted development limits for a loft conversion on a terraced house

Added roof volume: Up to 40m³ for a terraced house.
Roof plane: Must not extend beyond the plane of the existing roof slope on any elevation fronting a highway, and must not exceed the height of the existing roof.
Side-facing windows: Must be obscure-glazed and non-opening below 1.7m from the floor.

Article 4 directions and conservation areas can remove or tighten these rights locally — checked automatically above. Always confirm with a Lawful Development Certificate before starting work.

Cost of a loft conversion by region

London South East East of England South West West Midlands East Midlands North West Yorkshire and the Humber North East

Planning fees by council

Fees and decision times for a loft conversion vary by council. Find yours below.

London

South East

East of England

South West

West Midlands

East Midlands

North West

Yorkshire and the Humber

Leeds Sheffield York Bradford Kingston upon Hull Wakefield Barnsley Calderdale Doncaster East Riding of Yorkshire Kirklees North East Lincolnshire North Lincolnshire North Yorkshire Rotherham

North East

Newcastle upon Tyne Sunderland Middlesbrough Gateshead County Durham Darlington Hartlepool North Tyneside Northumberland Redcar and Cleveland South Tyneside Stockton-on-Tees

Rules version 2026.1 · last reviewed 2026-01-01