How likely is my planning application to get approved in Windsor and Maidenhead?

Planning permission in Windsor and Maidenhead sounds simple enough — submit an application, wait eight weeks, get an answer. But whether that answer is yes or no depends on a web of local constraints that most homeowners don't even know to look for. Tools like WhatCanIBuild exist precisely because the gap between "I think this is fine" and "this was actually refused" is wider here than people expect.

The borough looks quiet on the surface

SL4, SL6, SL5 — these postcodes feel like straightforward commuter territory. Extensions, loft conversions, outbuildings. Surely a fairly predictable planning environment?

Not quite. The Royal Borough of Windsor and Maidenhead carries a planning weight that doesn't show up in the postcode. With 966 listed buildings recorded across the borough, the chances that your property — or a neighbouring one — sits within a listed building's curtilage or influence zone are higher than most homeowners realise. And that changes what you can do, even if your own home isn't listed.

Then there's the conservation area question. Windsor itself is one of the most historically sensitive towns in England. Conservation area boundaries are drawn at street level, sometimes at plot level. Two houses on the same road can face entirely different requirements.

Green Belt adds a layer most people underestimate

Parts of Windsor and Maidenhead fall within Green Belt land — and Green Belt isn't just a designation that affects new builds. It can affect how extensions are assessed, what counts as disproportionate, and how the council weighs up your specific proposal.

Most homeowners applying for a rear extension or garden room don't think of themselves as doing anything controversial. But if your plot sits within or near Green Belt, the council's starting point is different — and so is your approval risk.

The precedent question nobody asks

Here's what most applicants don't consider: what has actually been approved and refused on properties like yours, on streets like yours, in the past few years?

Council planning portals tell you a decision was made. They don't tell you why similar projects on your road keep getting refused while identical ones three streets over sail through. They don't tell you what conditions were attached, what officer comments revealed, or what the pattern looks like for your specific project type in your specific part of the borough.

That pattern matters enormously — and it's invisible unless you know where to look. The best way to understand your actual approval odds, not just the theoretical framework, is to use WhatCanIBuild, which surfaces what's been approved and refused nearby and what that means for your project.

Your £548 is committed the moment you apply

The householder application fee in Windsor and Maidenhead is £548. That's spent whether your application succeeds or fails. More expensive than the fee, though, is the time — eight weeks of waiting, plus pre-application conversations, drawings, and any resubmission if it goes wrong.

The projects that go smoothly are usually the ones where the homeowner understood their specific risk profile before applying — not just the general rules, but what the combination of their property type, location, and project meant for their actual chances.

WhatCanIBuild shows you that combination: the constraints on your property, what's been approved and refused nearby, and what your approval odds look like for your specific project — before you commit.