How much does planning permission really cost in Hounslow?

Most homeowners in Hounslow start with the same question: "what's the fee?" And there is a straightforward answer — a householder planning application costs £258. But that number tells you almost nothing about what your project will actually cost, or whether it will succeed. The full picture depends heavily on your specific property, and most homeowners don't realise how quickly that picture changes. Tools like WhatCanIBuild exist precisely because the gap between "the fee" and "what this will actually cost me" is wider than most people expect.

The £258 is just the starting point

The Planning Portal charges a £258 application fee for a standard householder application, plus a £75.83 +VAT service charge for applications submitted online that attract a fee over £100. So before anything else, you're already past the headline number.

Then there are the professional fees. Most householders in Hounslow use an architect or planning consultant to prepare drawings and handle the application. That can add several hundred to several thousand pounds depending on the complexity. If your application hits a complication — a neighbour objection, a request for further information, a heritage assessment — costs climb further. Most homeowners don't budget for any of this upfront.

Conservation areas change the calculation

Hounslow has 28 conservation areas. Article 4 directions are in place in Gunnersbury and Bedford Park, removing certain permitted development rights that homeowners elsewhere take for granted. The Kew Gardens UNESCO World Heritage Site buffer zone also extends into the borough.

If your property sits within any of these designations — or near a listed building, in a flood zone, or subject to a tree preservation order — the rules that apply to you are not the same rules that apply to your neighbour two streets away. You might need additional assessments. Your application might face more scrutiny. And the difference between knowing you're in a conservation area and knowing what that actually means for your specific project, on your specific street, with your specific proposal — that's not something a fee table can tell you.

What really determines whether your money is well spent

The £258 fee is the same whether your application sails through in eight weeks or gets refused. What makes the difference — and what most homeowners have no visibility on — is what's actually been approved and refused on your street, for projects like yours, and why.

Were similar extensions on your road approved or knocked back? Did the conservation area designation create problems for your neighbours, or did they get through fine? What's the approval rate for your project type in this part of Hounslow? These are the questions that determine whether your application is a good bet or an expensive gamble — and they're not answered by knowing the fee.

The best way to understand what your specific property is actually up against — including the approval odds for your project type and what similar applications nearby have looked like — is WhatCanIBuild. It surfaces the things this article deliberately didn't tell you, because they depend entirely on your address.

Enter your address and find out what you're actually dealing with before you spend a penny.

WhatCanIBuild gives you a property-level picture — not a general guide.