Do I need planning permission in Merton?

Planning permission in Merton is one of those questions that sounds simple until you start digging. The borough stretches from Wimbledon Village to Mitcham, and the rules that apply to an Edwardian detached in SW19 can be completely different from those affecting a Victorian terrace in CR4 — even for the same type of project.

Permitted development exists — but it's not a free pass

Many common home improvements — loft conversions, rear extensions, outbuildings — fall under national permitted development rights, which means they can go ahead without a formal planning application. That sounds reassuring. But those rights come with conditions, and in Merton, a surprisingly large number of properties have had those rights restricted or removed entirely. Until you see what permitted development rights actually apply to your address — free, in about a minute, you're essentially guessing.

Conservation areas change everything

Merton has several designated conservation areas — Wimbledon Village, Wimbledon Common, Mitcham Cricket Green, and Cannizaro Park among them. If your property sits within or adjacent to one of these, works that would be completely fine a few streets away can require a full planning application. And it's not just whether you're in a conservation area — it's what kind of works you're proposing, which elevation they affect, and what the local character guidance says about that area specifically.

Article 4 Directions add another layer. Parts of Wimbledon Village are covered by Article 4 Directions, which strip away specific permitted development rights that you'd otherwise take for granted. Most homeowners don't realise their address falls under one until they've already made plans.

The Wimbledon Common edge effect

Wimbledon Common is Metropolitan Common Land and carries its own byelaws. Properties on the fringes of the Common face scrutiny that goes beyond standard planning rules. Even if your project looks like a routine garden structure or boundary treatment, proximity to the Common can make it anything but routine.

Why your neighbour's project isn't a reliable guide

This is where most homeowners trip up. They see a similar extension two doors down and assume the same rules apply to them. But planning decisions are made on individual properties, and approval next door doesn't mean approval for you. What was approved there, and why, tells you something — but only if you know how to read it. The best way to understand the actual approval record on your street is to look at what's been decided for similar projects near your property.

Different properties on the same street can sit in different flood zones, have different permitted development limits, or carry different local plan designations. A householder application in Merton costs £548 and takes around 8 weeks — a cost worth avoiding if you don't need permission, and a risk worth understanding before you proceed if you do.

The best way to know for sure

The question isn't just "do I need planning permission in Merton?" — it's whether your property, with its specific combination of constraints, needs it for your project. WhatCanIBuild maps exactly that. You can check your property's constraint mix and what it means for your approval odds — free, no signup needed.