My Neighbour Is Building an Extension — What Are My Rights?

01

First: Check If They Need Planning Permission

Not all extensions require planning permission. Under Permitted Development rules, your neighbour may be allowed to build without applying.

Extensions Often Allowed Without Permission

• Single-storey rear extensions up to 4m (detached) or 3m (attached)
• Can extend to 8m/6m with Prior Approval notification
• Side extensions (not rear): no wider than half the width of the original house (A.1(j))
• Not forward of the principal elevation

Extensions That Usually Need Permission

• Two-storey extensions
• Side extensions in some cases
• Extensions exceeding size limits
• Properties in conservation areas, AONB, or National Parks
• Flats and maisonettes

If your neighbour is also adding a garden room or outbuilding, see our guide on garden rooms and outbuildings for the specific permitted development rules that apply.

How to check: Search your council's planning portal for recent applications at their address.

02

If They Have Planning Permission

If permission was granted, your main concern is whether they're building according to the approved plans.

You Can:

• View the approved plans on the council's website
• Check if the build matches the drawings
• Report concerns to planning enforcement if it doesn't

You Can't:

• Object after permission is granted (the time for that has passed)
• Force them to change approved plans
• Claim compensation for loss of value (generally)

03

If There's an Active Application

If you've received a neighbour notification letter or found an active application:

You Have the Right To:

• View all submitted documents
• Submit a written objection (usually within 21 days)
• Speak at the planning committee (if it goes to committee). From 31 October 2026, householder applications must be decided by officers, not a committee (SI 2026/854, Sch 1), except retrospective applications, applications connected with a listed building consent application, and the council's own applications, which the nominated member (a councillor) and nominated officer can still refer to committee (SI 2026/854 Sch 2 paras 3 and 6; reg 6). The scheme does not apply where the planning authority is a National Park authority or the Broads Authority (TCPA 1990 s319ZZF(1)).

Grounds for Objection

Focus on material planning considerations:

✅ Valid Objections:

• Loss of light to your windows
• Overlooking and privacy impact
• Overbearing impact (sense of enclosure)
• Design out of keeping with the area
• Noise from relocated services
• Impact on trees or wildlife
• Highway safety

❌ Not Valid Objections:

• Loss of property value
• Loss of view
• Construction disruption
• Boundary disputes (civil matter)
• Personal issues with your neighbour
• Competition for business

04

What About Party Walls?

If the extension touches or is near your shared boundary, the Party Wall Act may apply.

Your neighbour must serve notice if:

• Building on or near the boundary line
• Cutting into a party wall
• Excavating within 3-6 metres of your foundations

Your Rights Under Party Wall Act:

• Receive proper notice (1-2 months before work)
• Consent or dissent
• Have a surveyor appointed (at their expense)
• Have your property's condition recorded
• Claim for any damage caused

This is separate from planning permission — they need both.

05

What If They're Building Without Permission?

If you believe they're building without required permission:

1. Search the planning portal — confirm no application exists
2. Report to enforcement — contact your council's planning enforcement team
3. Provide evidence — photos, dates, description of works
4. Wait for investigation — council will visit and assess

The council may:

• Confirm it's permitted development (no action)
• Ask them to apply retrospectively
• Serve an enforcement notice

06

Practical Steps to Take

1. Talk to Your Neighbour First

Many disputes can be resolved with a conversation. They may:

• Not realise the impact
• Be willing to adjust plans
• Explain the timeline

2. Document Everything

• Take dated photos
• Keep copies of correspondence
• Note times of disturbance
• Record any damage

3. Know the Timelines

4. Get Professional Advice If Needed

For complex cases, consider:

• Planning consultant (for planning objections)
• Party wall surveyor (for boundary issues)
• Solicitor (for legal disputes)

07

Common Questions

"They didn't notify me — is that allowed?"

Councils notify nearby properties, but there's no legal requirement to notify everyone. Your neighbour doesn't have to tell you personally. Check the planning portal regularly for applications near you.

"Their extension will block my light — can I stop it?"

You can object on grounds of loss of light, but it's not guaranteed to succeed. Councils consider impact but have to balance your concerns against their rights to develop.

"Can I claim compensation for reduced property value?"

Generally no. There's no right to compensation for loss of value due to neighbouring development (with very limited exceptions for major infrastructure).

"The builders are making noise at 7am — is that allowed?"

Construction hours are often controlled by conditions. Check the planning permission for approved working hours. If they're breaching conditions, report to enforcement.

08

Key Takeaways

1. Check if they need permission — they may not
2. Object during the application stage — not after
3. Focus on material considerations — not personal issues
4. Party Wall Act is separate — and gives you strong rights
5. Talk first, escalate later — most issues can be resolved

09

Monitor Applications Near You

Don't get caught out by surprise developments.

Search your postcode free · alerts free for 7 days →

Get notified whenever a new application is submitted near your property.

This guide is for general information only and does not constitute legal advice. For advice specific to your situation, consult a qualified planning consultant or solicitor.