What planning rules in Bromley catch homeowners out?

Bromley is one of London's most varied boroughs — and that variety extends to its planning rules. What's perfectly fine for a neighbour two streets away might require a full planning application for you. Most homeowners assume the rules are simple and universal. They're not — and that assumption is exactly what gets people into trouble. Tools like WhatCanIBuild exist precisely because the gap between "I think I'm fine" and "I actually am fine" is wider than most people expect.

Green Belt and Metropolitan Open Land change everything

Bromley has more Green Belt land than almost any other London borough. If your property sits within or adjacent to Green Belt or Metropolitan Open Land — and you might not know whether it does — the permitted development rights that apply to most homes simply don't apply to yours in the same way. The rules that let your friend in Beckenham extend without permission may not stretch to your garden in Chislehurst or Orpington. Most homeowners don't realise their postcode alone isn't enough to tell them which rules apply.

Article 4 directions — the rule removal most people have never heard of

The council has the power to remove permitted development rights in specific areas through something called an Article 4 direction. This means work that would normally be allowed without a planning application suddenly requires one — and there's no obvious sign outside your front door telling you this applies to you. Bromley has conservation areas across the borough, from Shortlands to Crystal Palace, and Article 4 directions are most common in exactly those kinds of settings. Whether your road is affected is a question your neighbour probably can't answer — and neither can a general rule-of-thumb guide.

It's not just about what you're building — it's about what's already happened

Planning rules don't just look at your project in isolation. What matters is the full history of your property — previous extensions, outbuildings, changes already made — and how your plans interact with that history. Two identical houses on the same street can have very different permitted development allowances depending on what's been done to each one before. This is one of the things that catches homeowners out most often: assuming their situation matches their neighbour's when the permitted development "budget", so to speak, may already have been spent.

This is also where knowing what's been approved and refused nearby becomes genuinely useful — not just what the rules say in theory, but what's actually been happening on your street. WhatCanIBuild shows you nearby approvals and refusals for similar projects, so you're not flying blind on what Bromley's planners actually accept in practice.

The best way to know where you stand

The honest answer is that no article can tell you whether your specific project, at your specific address, with your property's specific history and constraints, needs planning permission. The combination of Green Belt designations, Article 4 directions, conservation area rules, and property history means the answer genuinely depends on your property — not on general guidance. WhatCanIBuild gives you a picture built around your actual address: what's been approved nearby, what the local refusal patterns look like, and what your property's constraints really mean for your chances.