Hillingdon has relatively low conservation area coverage at 7%, so most streets remain eligible for permitted development when the design stays within national limits. Householder approvals in Hillingdon run at around 84% with an average decision time of 9 weeks.
In Hillingdon, whether a garage conversion needs planning permission depends on specific constraints — conservation area, Article 4, listed status or flood risk. Check your address to see which apply.
Converting an integral or attached garage to habitable space is generally permitted development under GPDO Schedule 2, Part 1, Class G, provided no extension or external enlargement is involved.
Read the full garage conversion planning guide for the national rules and application process.
The CanUBuild checker surfaces real recent applications close to your address — approvals and refusals — so you can see what the planning officers at Hillingdon Council have approved for comparable schemes. Nearby precedent is one of the strongest signals for your own chances.
In Hillingdon, the answer depends on whether your property sits in a conservation area (7% of the borough), is listed, or falls within an Article 4 direction. Most garage conversion proposals are permitted development for houses when they stay within GPDO limits and no local constraint applies. Check your exact address with the CanUBuild checker before spending on drawings.
Conservation areas in Hillingdon typically remove several permitted development freedoms. For a garage conversion, the Larger Home Extension route and some external alterations do not apply, so a full householder application is usually required. Planning officers at Hillingdon Council assess conservation area proposals against the specific character appraisal for the street.
Hillingdon Council currently averages around 9 weeks for householder applications. Complex garage conversion proposals — particularly those in conservation areas or on listed buildings — can take longer. Prior approval decisions for Larger Home Extensions are typically issued in 42 days.
Most garage conversions in Hillingdon are permitted development provided the work is internal and any new windows or doors match the house. Article 4 directions in parts of the borough can remove this right — always verify at address level.
Address-level constraints and recent decisions around the corner. No drawings needed.