How likely is my planning application to get approved in Lewisham?

Planning permission in Lewisham feels like it should be straightforward — you either can or you can't, right? In reality, two houses on the same road can face completely different outcomes for the same project, and most homeowners don't realise that until it's too late. Before you assume your extension or conversion is fine, it's worth taking a minute to find out what your specific address is actually up against — free, no signup needed.

Your postcode is only the starting point

Lewisham spans a huge range of character — from dense Victorian terraces in SE14 and SE8 to the more suburban streets of SE12 and SE6. That mix matters because planning decisions aren't made at the borough level. They're made street by street, sometimes property by property.

Blackheath, Telegraph Hill, Brockley, Lee Manor, and Forest Hill all sit inside conservation areas. If your property falls within one — or even near the boundary — the rules change. And the rules change differently depending on which conservation area, which street, and what you're proposing.

Article 4 Directions in several of Lewisham's Victorian conservation areas remove permitted development rights that homeowners elsewhere take for granted. Something as minor as changing a window or front door could require a full application. Most homeowners only discover this mid-project.

Flood zones are easy to miss

The Ravensbourne and Quaggy rivers run through parts of Lewisham, and the flood zones around them quietly restrict what certain riverside properties can build. If your garden backs onto or sits near one of these corridors, outbuilding classes that would normally apply to your property may not apply to yours.

The problem is that flood zone boundaries don't follow neat lines — they shift around individual plots. Your neighbour's outbuilding might be perfectly fine while yours triggers a separate assessment. The best way to know whether this applies to your property is to check how your flood zone status actually affects your project type.

What your neighbours got approved matters more than you think

Lewisham Council typically aims to decide householder applications within 8 weeks, and the £548 fee is non-refundable whether you're approved or refused. That makes getting the pre-application picture right genuinely important.

Local precedent — what's been approved and refused on your street and nearby — is one of the strongest indicators of how your application will land. A loft conversion that sailed through three doors down is a very different signal from one that was refused with conditions two streets over. But knowing why something was refused, and whether those reasons apply to your property too, is the part most homeowners skip.

That's the gap between knowing you're in a conservation area and knowing what it actually means for your loft, your extension, or your outbuilding. WhatCanIBuild pulls together approval records, constraint layers, and local precedent so you can see what's been approved near your street and what your odds look like — free, takes about a minute.