Check your Permitted Development Rights in Minutes
Get instant planning compliance assessment for your home extension project. Professional reports ready for submission to your local authority.
Extension Summary
Popular Extension Types
Professional assessment for all types of home extensions
Single-Story Extensions
Kitchen extensions, dining room extensions, and living space additions.
- Up to 6m depth (detached)
- Up to 4m depth (semi/terraced)
- Maximum 4m height
- Material matching required
Two-Story Extensions
Double-height extensions for additional bedrooms and bathrooms.
- Up to 3m depth (semi/terraced)
- Up to 6m depth (detached)
- Height restrictions apply
- Neighbor consultation may be required
Side Return Extensions
Popular Victorian terrace extensions filling in the side return passage.
- Single-story only under PD
- Max half original house width
- 4m maximum height
- Material matching required
Home Extension Planning Requirements
Size Limits
Extensions must stay within permitted development size limits based on your property type and existing extensions.
Height Restrictions
Maximum heights apply for different roof types, with special rules for extensions near boundaries.
Materials & Design
External materials should match the existing house, with considerations for conservation areas.
Quick Size Calculator
Maximum Extension Depth
| Property Type | Single-Story | Two-Story |
|---|---|---|
| Detached | 6m depth | 6m depth |
| Semi-Detached | 4m depth | 3m depth |
| Terraced | 4m depth | 3m depth |
Height Limits
- Single-story: 4m max
- Two-story: varies by roof type
- No higher than original roof
Boundary Rules
- 2m+ from boundary: any height
- Within 2m: 3m max height
- Side extensions: special rules
Important Extension Considerations
Key factors to consider before starting your home extension project
Boundary Distances
Extensions within 2m of boundaries are limited to 3m height. Plan carefully to maximize space while staying compliant.
Material Matching
Extensions must use materials that match or complement the original house. This includes bricks, roof tiles, and windows.
Neighbor Consultation
Two-story extensions over 3m deep require neighbor consultation. The larger extension procedure adds 6 weeks to the process.
Property Type Limits
Detached houses can extend 6m, while semi-detached and terraced houses are limited to 4m for single-story extensions.
Conservation Areas
Properties in conservation areas face additional restrictions and may need full planning permission for extensions.
Building Regulations
Even permitted development requires Building Regulations approval for structural safety, insulation, and accessibility.
Height Restrictions
Maximum heights apply for different roof types, with special rules for extensions near boundaries.
Previous Extensions
Existing extensions count towards your permitted development allowance. Extensions built since 1948 must be included in size calculations.
Article 4 Directions
Local authorities can remove permitted development rights in specific areas. Check with your council about any Article 4 directions affecting your property.
Frequently Asked Questions
Common questions about home extension planning permission
What Our Customers Say
Real feedback from homeowners who used our home extension assessment service
"The extension report was incredibly detailed and helped us understand exactly what we could build under permitted development. Saved us thousands in planning fees."
"Clear guidance on boundary distances and height restrictions. The professional report gave us confidence to proceed with our extension project."
"Excellent service that identified potential issues early. The report helped our architect design a compliant extension from the start."
Ready to Check Your Home Extension?
Get your professional compliance assessment in minutes
Start Your Extension Assessment Now