Planning Permission Checker
Find out whether your home improvement project is likely to be permitted development or needs planning permission. Free instant results for England, with guidance for Wales, Scotland, and Northern Ireland.
Not every home improvement needs planning permission — and knowing the difference before you start can save you thousands. Permitted development rights allow many common projects such as single-storey rear extensions, loft conversions with roof lights, and garden outbuildings to go ahead without a formal application.
The rules depend on your property type, its location, and whether it sits in a conservation area or is a listed building. A detached house, for example, enjoys more generous limits than a flat or maisonette. Getting it wrong can mean enforcement action, demolition orders, or serious problems when you come to sell.
According to the Ministry of Housing, Communities & Local Government, local planning authorities in England received approximately 457,000 householder planning applications in the year to March 2024 (GOV.UK Planning Statistics). Many of those could have been avoided with a proper permitted development check.
How this checker works
- Select your property type, location, and whether any special designations apply.
- Choose the type of work you are planning and enter the key dimensions.
- The checker compares your inputs against the current permitted development thresholds for your nation and returns a traffic-light verdict: green (likely PD), amber (borderline), or red (planning application likely needed).
Written by the CalcStack team · Last updated April 2026
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Site Constraints Report
Search real planning constraints for any UK postcode
Enter your postcode to check 12 planning databases including conservation areas, listed buildings, flood risk zones, green belt, TPOs, AONBs, Article 4 directions, and more. Data sourced from the official Planning Data API (planning.data.gov.uk).