This is general guidance based on standard permitted development rights in England. Rules differ for listed buildings, conservation areas, and properties with Article 4 directions. Always confirm with your local planning authority before starting work.
Do I Need Planning Permission for a Bi-Fold or Sliding Doors?
Installing bi-fold, sliding, or French doors, typically to open up a living space onto a garden or patio. Replacing an existing window or door opening with bi-folds is usually PD; creating a new large opening in the wall has additional considerations.
The General Position
This project is usually allowed under permitted development rights without needing to apply for planning permission, provided certain conditions and limits are met.
Generally permitted. Replacing existing doors or windows with bi-fold or sliding doors is treated as improvement and does not usually require planning permission. Enlarging the opening may be PD under Part 1 provided it does not significantly alter the building's appearance.
Conditions and Requirements
- 1Replacing an existing door or window with bi-folds of a similar size is generally PD
- 2Enlarging the opening requires structural work and Building Regulations approval
- 3Materials and appearance should be in keeping with the existing property
- 4Rear installations are more likely to be PD than front-facing ones
Size and Dimension Limits
- No specific PD dimension limits for replacement doors
- Structural limits depend on the wall type and lintel requirements
When Permitted Development Does Not Apply
- Listed buildings require listed building consent
- In conservation areas, bi-folds on front or highway-facing elevations may need PP
- Large openings in structural walls require engineer-designed lintels or steel beams
- Ensure adequate drainage and threshold detailing to prevent water ingress
What About Building Regulations?
Building Regulations approval is required covering structural support (steel beams or lintels for large openings), thermal performance of the glazing (Part L), safety glazing (Part K), security (Part Q, PAS 24), and ventilation. FENSA or CERTASS-registered installers can self-certify the glazing element.
Building regulations are separate from planning permission. You may need both, one, or neither depending on your project. Building regulations cover the safety and quality of building work, including structural integrity, fire safety, insulation, ventilation, and drainage.
How to Apply for Planning Permission
Check if you need permission
Review the permitted development rules above. If in doubt, contact your council or apply for a Lawful Development Certificate.
Prepare your application
You will need scaled drawings, a site plan, and a completed application form. An architect or planning consultant can help with this.
Submit to your local council
Applications can be submitted online via the Planning Portal or directly to your council. Select your council below for a direct link.
Wait for a decision
8 weeks for householder planning applications if PP is needed..
Application cost: £258.
What Happens If I Build Without Permission?
Low risk for rear-facing bi-folds replacing existing openings. Higher risk in conservation areas or on front elevations. The main practical issue is ensuring Building Regulations compliance for the structural opening.
Find a Window Fitter for Your Bi-Fold or Sliding Doors
Browse local window fitters on Tradesfolk. Read reviews, compare quotes, and hire with confidence. 100% free for homeowners.
Select Your Council
Choose your local council for guidance specific to your area, including links to apply and whether your council has conservation areas or Article 4 directions that could affect your project.
London
South East
South West
East of England
East Midlands
West Midlands
North East
North West
Yorkshire and the Humber
CA = has conservation areas. A4 = has Article 4 directions. These may restrict your permitted development rights.