Your extension potential checker — instant results, no waiting.
Find out whether your property has the potential to be extended — based on millions of planning data points across England.
Start with your door number, then street & postcode. Pick your address from the dropdown.
- · Free instant report
- · No signup to start
- · England-wide planning data
Question 1 of 5
What type of property is this?
Question 2 of 5
Which floor is the flat on?
This helps narrow the extension types. For example, a top floor flat is normally only relevant for loft / roofspace potential.
Question 2 of 5
What extension are you considering?
Choose the closest extension type. This will also focus the nearby planning applications.
Question 3 of 5
What shape is the property?
Question 4 of 5
Has this property been extended before?
Previous extensions can affect how much additional space may be available under planning or permitted development rules.
Question 5 of 5
What is the property's tenure?
Almost done
Where should we send the report?
Enter your details to view your extension potential summary.
Extension report
Moderate extension potential
A quick planning-led snapshot of the property based on your answers, nearby applications and public planning constraints.
Initial notes
A short interpretation of the current result.
Possible risks
These risks inform where and how you can extend.
Also checked
These checks were reviewed and do not currently present a major issue.
Applications
Nearby applications sorted by your selected view.
Building Regulation Drawings
All time
Established
Trusted since
Qualified
Professionally accredited
BC Submission Included
No hidden costs
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Can I extend
my house?
Most homeowners spend weeks chasing architects and planning consultants before they even know what their property can achieve. Our Extension Potential Checker changes that.
Enter your address and answer a few quick questions. In minutes you get a free report covering planning history nearby, permitted development limits, and any constraints that could affect your project — before you spend a penny.
Whether you are thinking about a single storey extension, a double storey extension, or a loft conversion, start here.
Going in blind
- × No idea what neighbours have had approved nearby
- × Unaware of Article 4 directions or conservation area restrictions
- × Guessing whether permitted development applies to your plot
- × Paying for a feasibility study before you know the basics
- × Wasting time on a scheme that planning will never pass
REPORT
Know before you commit
- ✓ Approved and refused applications on nearby properties
- ✓ Permitted development size limits for your property type
- ✓ Conservation area, Article 4 and flood zone flags
- ✓ Realistic extension types suited to your plot
- ✓ Clear next steps — no jargon, no sales pressure
Frequently Asked Questions
Is the checker free to use
Yes, completely free. No sign-up, no card details, and no obligation to instruct us afterwards. You get your report immediately.
What is permitted development?
Permitted development rights let you carry out certain home improvements without a full planning application, subject to size and condition limits. The rules differ for houses and flats and can be removed by an Article 4 direction in some areas. The checker gives you an initial steer on whether your project is likely to qualify.
Does the report replace professional advice?
No. The checker gives you a solid starting point but it is not a substitute for a full planning appraisal. Planning rules are complex and site-specific. If your report flags constraints or you want a detailed feasibility review, we offer a paid planning appraisal service.
Which extension types does it cover?
The checker covers single storey rear and side extensions, double storey extensions, and loft conversions. It flags which options are realistic for your property type and plot.
Do you cover all London boroughs?
Yes. We work across all London boroughs including Westminster, Kensington and Chelsea, Hammersmith and Fulham, Hounslow, Richmond, Wandsworth, Brent, Harrow, and Hillingdon.
What happens after I get my report?
You can use the report to have an informed conversation with us or any architect. If you would like AC Design Solution to take the project forward, contact us from the results page and we will provide a fixed fee quote, usually the same day.