How likely is my planning application to get approved in Hillingdon?

Planning permission in Hillingdon isn't a single question with a single answer. Whether your application gets approved depends on a layered combination of factors that vary not just by borough, but by street — and sometimes by individual property. WhatCanIBuild exists precisely because that complexity is almost impossible to untangle without looking at your specific address.

Hillingdon isn't one place — it's many

Hillingdon is one of London's largest boroughs, stretching from Heathrow in the south to the outer reaches of Ruislip and Northwood in the north. The planning picture looks completely different depending on where you are. The borough contains 31 conservation areas, significant areas of Green Belt, and properties subject to specific local plan policies tied to Heathrow Airport's proximity.

Being in a conservation area doesn't automatically mean refusal — but it changes everything about what's acceptable, how it needs to look, and what the council will scrutinise. Most homeowners don't realise that two houses on the same street can face entirely different planning constraints depending on which side of a boundary they sit on.

The constraints you can't see from the outside

Even if your project sounds straightforward — a rear extension, a loft conversion, a new outbuilding — there's a long list of property-specific factors that can quietly reshape your chances:

• Article 4 Directions that remove permitted development rights in certain areas
• Listed building status that affects not just the building itself but sometimes the land around it
• Flood zone designations that trigger additional requirements
• Green Belt classifications that apply stricter tests to any new development
• Heathrow-related height and safeguarding policies that affect properties across a wide area

Any one of these could be sitting on your property title without you knowing. And their combined effect on your specific application isn't something a general guide can tell you.

What actually predicts approval — and what doesn't

Here's what most homeowners get wrong: they look at general approval rates and assume their project falls within the norm. But approval rates are averages across thousands of very different applications. What actually predicts whether your application succeeds is much more specific.

Has a similar project been approved on your street before? Was it refused nearby — and if so, why? How has the council treated applications of your type in your ward recently? These aren't questions you can answer from a government statistics page. They require looking at real decision data for your area, your project type, and your property's constraint profile.

The best way to understand your actual odds — not just the generic picture — is to use WhatCanIBuild, which pulls together approval and refusal data for projects like yours near your address, so you can see what's actually been happening on the ground in Hillingdon rather than guessing.

What you don't know could be expensive

Submitting an application without understanding your property's full constraint picture is a gamble. In Hillingdon, where Green Belt, conservation areas, and Heathrow policies create a patchwork of different rules, the gap between what you assume and what applies to your property can be significant.

WhatCanIBuild shows you what's been approved and refused for similar projects near your address — the kind of specific, local insight that makes the difference between an informed application and an expensive mistake.