Planning permission in Lewisham isn't a simple yes or no — and most homeowners only discover that after they've already committed to something. The borough has layers of local rules that sit on top of national permitted development rights, and whether your project needs permission can come down to your specific address, your specific property, and even what your neighbours have done before you. WhatCanIBuild was built for exactly this kind of complexity.
The short version
- Lewisham has over 25 conservation areas, and they don't all work the same way
- Article 4 directions can remove permitted development rights — and most homeowners don't know if they apply to their property
- A householder application costs £258 and typically takes 8 weeks — getting it wrong is expensive
Your property might not be covered by the rules you think
National permitted development rights let you do certain work without applying for planning permission. Most homeowners know that. What they don't know is that those rights can be restricted — or removed entirely — at a local level, and Lewisham has done exactly that in several areas.
Article 4 directions are in place around parts of the borough, including areas near Blackheath and Ladywell. If your property falls within one, work that would normally be permitted development could require a full application. Do you know whether your address is affected? Most people don't — until they check.
Conservation areas are not all the same
Lewisham has over 25 designated conservation areas, covering large chunks of the borough. If you're in one, the rules around what you can do — extensions, loft conversions, changes to the front of your property, outbuildings — shift considerably.
But here's what most homeowners miss: being in a conservation area tells you very little about what you can actually do. The real question is what that conservation area designation means for your project type, on your property type, on your specific street. That's where things get complicated — and where a lot of applications run into trouble.
Worth knowing
If your property is listed, permitted development rights are even more restricted. Grade II listed buildings are more common in Lewisham than many homeowners realise — and listed building consent is a separate process from planning permission entirely.
Approval rates vary more than you'd expect
Even within the same street, similar projects can get very different outcomes. A rear extension that sailed through for a neighbour three years ago might face objections today. A loft conversion that was refused two doors down might succeed with a different design. The pattern of what's been approved and refused in your area matters — and it's not something you'd know just from reading the rules.
This is the part that catches people out. They read a general guide, decide their project sounds like it should be fine, and either skip the application or submit something that doesn't reflect how decisions are actually made locally.
The best way to know what applies to your property
The best way to check isn't to guess based on general rules — it's to look at what's actually happened on your street and what constraints are stacked against your specific address. WhatCanIBuild pulls together your property's constraint profile alongside local approval and refusal data, so you can see what your project is actually up against — not just whether you're technically in a conservation area, but what that means for a project like yours.
If you're planning an extension, loft conversion, outbuilding, or any other work on your Lewisham home, the combination of conservation area status, Article 4 directions, listed building status, and local decision patterns makes this genuinely hard to call without looking at your specific address.
WhatCanIBuild shows you what those factors actually mean for your project — including what similar projects nearby have been approved or refused, and why.
These rules vary by property
Conservation areas, Article 4 directions, and other constraints can change everything. Check what actually applies to your address.
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