Garden Room Permitted Development
London 2026
The complete guide to what you can build without planning permission — and why a £103 Lawful Development Certificate is still the most important document on your project.
The Four PD Criteria for Garden Rooms
Under Class E of Schedule 2, Part 1 of the Town and Country Planning (General Permitted Development) (England) Order 2015, garden outbuildings are permitted development provided all four of the following criteria are met simultaneously. Failing any single one means you need full planning permission.
Height within 2m of boundary
Maximum total height (including roof) of 2.5m if any part of the structure is within 2 metres of a property boundary. More than 2m from every boundary: up to 4m (dual pitch) or 3m (mono pitch).
Garden coverage
Combined outbuildings (shed, garage, office, decking) must not exceed 50% of the original curtilage. This is measured from the original house footprint, not any subsequent extensions.
Ancillary use
The building must be 'incidental to the enjoyment of the dwelling house.' Office, gym, studio, art room — all qualify. Sleeping accommodation does not.
Position
Cannot be built forward of the principal (street-facing) elevation. Rear and side gardens only.
Listed buildings
PD rights do not apply to listed buildings. Any outbuilding requires Listed Building Consent regardless of size or use.
Article 4 directions
Some London conservation areas have Article 4 Directions that remove PD rights for outbuildings. Check your address on your council's planning map before engaging any installer.
The Lawful Development Certificate: Why £103 Matters
You do not legally need an LDC to build under Permitted Development — the build is lawful regardless. But when you sell, remortgage, or let the property, your buyer's solicitor will ask for planning evidence for every outbuilding on the site. Without an LDC, you must provide retrospective proof (invoices, photographs, planning correspondence) that it was PD-compliant at the time it was built. This delays exchange and creates risk.
With an LDC, the answer is a single document. At £103, it costs approximately 0.5% of a standard garden office build. There is no rational case for not obtaining one.
2026 LDC Costs — All London Boroughs
How to Apply: Step by Step
Confirm your PD position
Check height, coverage, position, and use against the four PD criteria. Your installer does this as part of the free site survey.
Prepare application documents
Site location plan (1:1250), block plan with dimensions (1:500), and elevation drawings showing height and boundary distances.
Submit to your LPA
Via planningportal.co.uk or directly to your council. The 2026 fee is £103 for a Certificate of Lawfulness for Proposed Development.
Wait for determination
The statutory period is 8 weeks. Most London boroughs meet this target for complete applications.
File your certificate
Store with your title deeds. Your solicitor will provide it to any future buyer's solicitor as proof of lawful status.
Conservation Areas & Article 4 Directions
If your property is in a designated Conservation Area, Article 4 Directions may remove the PD rights that apply everywhere else in London. Areas with known Article 4 restrictions on outbuildings include parts of Hampstead, Highgate, Islington, Kensington, Richmond, and Wandsworth. Conservation area restrictions do not make a garden room impossible — they require full planning permission with a well-designed, sympathetically specified proposal. Our recommended installers check your conservation area status at survey stage.
All London Borough Planning Portals
| Area | Council | Status | LDC Fee | Portal |
|---|---|---|---|---|
| Eastcote | London Borough of Hillingdon | ✓ Standard PD | £103 | Portal |
| Hampstead | London Borough of Camden | ⚠ Conservation Active | £103 | Portal |
| Harefield | London Borough of Hillingdon | ✓ Standard PD | £103 | Portal |
| Harrow | London Borough of Harrow | ⚠ Conservation Active | £103 | Portal |
| Hayes | London Borough of Hillingdon | ✓ Standard PD | £103 | Portal |
| Ickenham | London Borough of Hillingdon | ⚠ Conservation Active | £103 | Portal |
| North Harrow | London Borough of Harrow | ✓ Standard PD | £103 | Portal |
| Northolt | London Borough of Ealing | ✓ Standard PD | £103 | Portal |
| Northwood | London Borough of Hillingdon | ✓ Standard PD | £103 | Portal |
| Pinner | London Borough of Harrow | ⚠ Conservation Active | £103 | Portal |
| Rickmansworth | Three Rivers District Council | ⚠ Conservation Active | £103 | Portal |
| Ruislip | London Borough of Hillingdon | ⚠ Conservation Active | £103 | Portal |
| Stanmore | London Borough of Harrow | ✓ Standard PD | £103 | Portal |
| Uxbridge | London Borough of Hillingdon | ⚠ Conservation Active | £103 | Portal |
| Watford | Watford Borough Council | ⚠ Conservation Active | £103 | Portal |
| West Drayton | London Borough of Hillingdon | ✓ Standard PD | £103 | Portal |
| West Hampstead | London Borough of Camden | ⚠ Conservation Active | £103 | Portal |
| Bushey | Hertsmere Borough Council | ✓ Standard PD | £103 | Portal |
Planning & Advice guides