Southwark looks straightforward on paper — but the borough has more planning trip-wires per square mile than almost anywhere in London. What's allowed on one street can be completely off-limits two roads away, and most homeowners only find that out after they've already started work.
The short version
- Southwark has numerous conservation areas, each with its own restrictions
- Article 4 Directions remove permitted development rights across many Victorian terraces
- The Dulwich Estate adds a private layer of control that sits entirely outside standard planning rules
- Flood zones near the Thames affect what you can build and how
Conservation areas aren't all the same
Southwark has conservation areas covering Borough, Bermondsey, Dulwich Village, Herne Hill, Peckham Rye, and more. Being inside one changes what you can do without planning permission — but being outside one doesn't automatically mean you're free to build. The edges of these areas are often poorly understood, and some homeowners assume they're unaffected until they check what constraints are actually attached to their specific address — free, takes about a minute.
What trips people up isn't knowing they're in a conservation area. It's not knowing what that actually means for their specific project — a rear extension that sailed through for a neighbour may require full permission for you depending on which part of the area you're in and what's already been done to the property.
Article 4 Directions — the rule most people have never heard of
Across large swathes of Southwark's Victorian terraces, Southwark Council has issued Article 4 Directions. These remove permitted development rights that would otherwise let you make changes without applying for planning permission. That means work you'd assume is fine — changing window styles, altering a front elevation, certain roof works — may need a full application.
The problem is that Article 4 Directions are property-specific. Your neighbour might be unaffected while your house is covered. Most homeowners don't realise this until they're already mid-project. The best way to know is to check whether an Article 4 Direction applies to your property.
Dulwich Village — a different set of rules entirely
Dulwich Village sits within the Dulwich Estate Scheme of Management — a private governance layer that operates alongside standard planning rules. Even if Southwark Council approves your project, the Estate may still refuse it. This is separate from listed building consent and separate from conservation area controls. If your property is within the Estate, you're playing by two sets of rules simultaneously.
Listed buildings and flood zones add more variables
Listed buildings cluster along the Thames frontage and around Southwark Cathedral — and the designation affects not just the building itself but sometimes the curtilage around it. If your property is near a listed building rather than being one, that can still affect what's permissible nearby.
Flood zones near the river add another layer. Certain types of extension or basement work trigger additional requirements that don't apply elsewhere in the borough — and the boundary of what's affected isn't always obvious from a postcode.
Your property's combination of constraints is what matters
One conservation area designation might mean very little for your project. Add an Article 4 Direction on top, a nearby listed building, and proximity to a flood zone, and you're in genuinely complex territory. The approval record for similar projects on your street — what got through, what was refused, and why — is the most useful thing to understand before you commit to anything.
WhatCanIBuild pulls together your property's specific constraint mix and shows you the approval record for your area. See what similar projects near your street actually got approved for, and what that means for your odds — no signup needed.
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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