Planning permission in Lewisham isn't a simple yes or no — it depends on your property, your street, and a layer of local restrictions that most homeowners don't realise exist until it's too late. Before you assume your project is straightforward, it's worth taking a moment to find out what constraints apply to your specific address — free, in about a minute.
The short version
- Lewisham has multiple conservation areas with tighter-than-normal rules on alterations
- Article 4 Directions in several Victorian streets remove permitted development rights you'd normally have
- Flood zones along the Ravensbourne and Quaggy rivers add another layer of restriction for riverside properties
- What was approved for your neighbour may not apply to you
Your permitted development rights might not be what you think
Most homeowners know that some work — like certain extensions or loft conversions — doesn't automatically need a planning application. What they don't know is that those rights can be stripped away entirely depending on where you live.
Lewisham has conservation areas covering Blackheath, Telegraph Hill, Brockley, Lee Manor, and Forest Hill. If your property sits within one of these, the rules change. But here's the part that catches people out: even within a conservation area, the exact restrictions vary. An Article 4 Direction in parts of the borough specifically removes permitted development rights for window and door alterations in Victorian terraces — something that wouldn't normally require permission at all.
Do you know whether your property is covered by one of these directions? Most people don't, until they've already started work.
North Lewisham and south Lewisham aren't the same borough
The borough spans genuinely different types of housing stock — dense inner-city terraces in areas like New Cross and Deptford, through to more suburban streets around Catford and Grove Park. That matters because the planning history, the character assessments, and the likelihood of approval for a given project type can differ significantly even within the same postcode.
A rear extension that sailed through in SE12 might face scrutiny in SE4. The approval record for similar projects on your specific street is the data point that actually tells you something useful — and that's not something you can easily piece together yourself.
Flood zones add a layer most homeowners miss
Properties near the Ravensbourne and Quaggy rivers face additional restrictions that don't apply to the rest of the borough. Certain outbuilding classes work differently — or don't apply at all — for riverside properties in flood zones. If your garden backs onto or near a watercourse, the calculation for what you can build changes considerably.
The best way to know whether this applies to you is to check how your flood zone status affects your specific project type — because the answer isn't the same for everyone in SE6 or SE13.
Don't rely on what your neighbour did
A project approved next door doesn't mean yours will be. Listed building status, plot boundaries, and constraint combinations are property-specific. Even identical houses on the same street can have different planning histories.
What actually determines your chances
Knowing you're in a conservation area is one thing. Knowing what that means for your specific project — whether similar applications nearby were approved or refused, and why — is something else entirely. Lewisham Council takes around 8 weeks to decide householder applications, and a £548 fee is non-refundable whether you're approved or not.
With WhatCanIBuild, you can see what's been approved on streets like yours and what your odds realistically look like — no signup required. That's the information worth having before you commit.
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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