Talking to Neighbours About Your Extension

Nothing poisons a building project faster than a neighbour who finds out about your extension from a council letter. That formal notification, landing on their doormat with no warning, turns a straightforward planning application into a grudge match. And grudge matches generate objections.

The irony is that most neighbour objections carry no planning weight whatsoever. "I don't want an extension next door" is not grounds for refusal. But an angry neighbour who feels blindsided will find reasons to object, and even baseless objections create stress and delays, sometimes triggering a referral to the planning committee.

You can avoid almost all of this by knocking on the door before you submit.

When to Have the Conversation

Talk to your immediate neighbours after you've confirmed your planning route but before you submit anything to the council. If you've already read Do You Need Planning Permission?, you'll know whether you're going down the permitted development route or applying for full planning permission.

If you need planning permission, talk to neighbours at least a week before you submit your application. That gives them time to digest the news before the official council letter arrives.

If you're building under permitted development, you don't technically need to tell anyone. But you should. Neighbours notice a digger in the back garden. Finding out over the fence on day one of demolition is worse than finding out from the council. It's also worse than hearing it from you.

For extensions going through the Neighbour Consultation Scheme (prior approval for larger extensions), the council will formally consult adjoining properties regardless. Even so, a heads-up from you first shifts the whole tone of the process.

What to Say

Keep it simple. You're informing them, not asking permission.

Knock on the door. Tell them you're planning to build an extension. Describe it in plain English: "a single-storey rear extension, about four metres out from the back wall." Mention the rough timeline: "we're hoping to start in the summer and it'll take around four to five months." If the build will affect them directly (shared access, noise, a party wall, disruption to parking), say so. Give them your phone number.

That's it.

Don't overcomplicate this. The goal is for the council letter to feel like confirmation of something they already knew, not a surprise.