The Party Wall Act: A Plain English Guide for Homeowners

A party wall is a wall that stands on the land of two or more owners and forms part of a building. The most common example is the wall between two semi-detached or terraced houses.

But the Act covers more than just party walls:

• Party walls — walls shared between two properties (Section 2)
• Boundary walls — walls that sit entirely on one owner’s land but are used by both properties to separate them
• Party fence walls — walls that sit astride a boundary but are not part of a building (such as a garden wall on the boundary line)
• Party structures — includes floors and ceilings between flats

The Act applies in three situations, each covered by a different section:

Section 1 — Building a new wall on the boundary line

If you want to build a new wall or foundation on the boundary line between your property and your neighbour’s, you must serve a Section 1 notice. This includes building a new garden wall on the boundary or building a new extension wall on the boundary line. You must give at least 1 month’s notice before work starts.

Section 2 — Work to an existing party wall

If you want to carry out work to an existing party wall or party structure, you must serve a Section 2 notice. This is the most common trigger and includes:

• Cutting into a party wall to insert a steel beam (for a loft conversion or extension)
• Raising or lowering a party wall
• Demolishing and rebuilding a party wall
• Underpinning a party wall
• Cutting away part of a party wall to weatherproof a new extension
• Inserting a damp-proof course into a party wall
• Making the party wall thicker (such as adding insulation)

You must give at least 2 months’ notice before work starts.

Section 6 — Excavation near a neighbouring building

If you are digging foundations near a neighbouring building, you must serve a Section 6 notice. This catches many people out because it applies even if the neighbour’s building is not on the boundary. Section 6 applies if:

• Your excavation is within 3 metres of a neighbouring building and goes deeper than the bottom of their foundations
• Your excavation is within 6 metres of a neighbouring building and would cut a 45-degree line drawn downwards from the bottom of their foundations

In practice, almost every rear extension on a terraced or semi-detached house triggers Section 6 because the foundations for the extension are dug near the neighbouring building. You must give at least 1 month’s notice before work starts.

1. Serve the notice

You must serve a written notice on every “adjoining owner” affected by the work. An adjoining owner is anyone who owns property that shares a boundary or party wall with your work, or whose building is within the relevant distance for Section 6.

The notice must include:

• Your name and address
• A description of the proposed work
• The date you plan to start
• The relevant section of the Act (Section 1, 2, or 6)

Notices can be delivered by hand or sent by post. Keep proof of delivery.

2. Wait for a response

Your neighbour has 14 days to respond. They can:

• Consent — they agree to the work. You can proceed on the date stated in the notice. No surveyor is needed.
• Dissent — they do not agree. The Act then requires the appointment of surveyors to resolve the matter.
• Not respond — silence for 14 days is treated as dissent.

3. If your neighbour consents

Write up the consent in a simple letter that both parties sign. The work can proceed as described in the notice. No party wall award is needed.

4. If your neighbour dissents (or does not respond)

This triggers the surveyor process. Two important points:

• Dissent does not mean the work cannot go ahead. It means the details need to be agreed through surveyors.
• Your neighbour cannot prevent the work. The Party Wall Act gives you the right to carry out the work — the surveyor process simply agrees the terms and protects both parties.

When a neighbour dissents, surveyors are appointed to prepare a party wall award — a legal document that sets out what work will be done, how, and when.

Appointing surveyors

There are two options:

Agreed surveyor (one surveyor acting for both parties): This is the simplest and cheapest option. Both you and your neighbour agree on a single surveyor who acts impartially for both sides. Most straightforward residential cases use an agreed surveyor.

Two surveyors (one each): You appoint your own surveyor, your neighbour appoints theirs, and the two surveyors work together to agree the award. If they cannot agree, they appoint a third surveyor to decide. This is more expensive and is usually only necessary when the work is complex or the relationship has broken down.

The party wall award

The surveyors prepare an award that typically includes:

• A description of the work to be carried out
• A schedule of condition — a detailed photographic record of the neighbouring property before work starts (this protects both parties if damage occurs)
• Any conditions on how and when the work is done (working hours, access arrangements)
• Who pays the surveyor fees (usually the building owner)
• How any damage will be repaired

The award is legally binding on both parties.

The building owner (the person doing the work) usually pays all surveyor fees, including the neighbour’s surveyor. This is standard practice under the Act, though the award can allocate costs differently.

These costs are per neighbour. If your extension affects neighbours on both sides (for example, a rear extension on a mid-terrace house), you need separate notices and potentially separate awards for each neighbour.

How to minimise costs:

• Talk to your neighbour first. Explain the work, show them the plans, and answer their questions. A neighbour who understands what is happening is much more likely to consent.
• Suggest an agreed surveyor. One surveyor is cheaper than two.
• Serve notices early. The notice periods (1 or 2 months) run before construction starts. Serve them as soon as your plans are finalised to avoid delaying your build.

If your neighbour does not respond within 14 days, their silence is treated as dissent. You then have two options:

1. Appoint an agreed surveyor and write to your neighbour informing them of the appointment. If they do not object within 10 days, the agreed surveyor can proceed.
2. Appoint your own surveyor and write to your neighbour asking them to appoint theirs within 10 days. If they do not, your surveyor can appoint a surveyor on their behalf.

Your neighbour cannot prevent the process by ignoring it. The Act has mechanisms to keep things moving.

Under the Act, you (and your builder) have a right of access to your neighbour’s property if it is necessary to carry out the work. This must be set out in the party wall award.

If your neighbour refuses access after the award has been made, they are in breach of the award. You can apply to the courts for an injunction to enforce access. In practice, this rarely happens — the surveyor usually resolves access issues in the award.

You must give your neighbour 14 days’ notice before accessing their property.

The schedule of condition prepared before work starts is the key document here. If damage occurs to your neighbour’s property during the work (cracking, structural movement, water damage), it is compared against the schedule of condition.

If the damage was caused by your work, you are responsible for making good — either by repairing the damage or paying compensation. This obligation applies regardless of fault (it is a strict liability under the Act).

If there is a dispute about whether the damage was caused by the work, the surveyors determine this.

This is one reason why having a proper party wall award with a thorough schedule of condition protects you. Without it, your neighbour could claim pre-existing damage was caused by your work.

1. Not serving notice. If the Party Wall Act applies and you do not serve notice, your neighbour can seek an injunction to stop work. This can halt your entire project and cost thousands in legal fees. Always serve the notice — even if you think your neighbour will be fine with it.

2. Serving notice too late. Section 2 notices require 2 months’ notice. If you serve the notice the week before your builder is due to start, you have guaranteed a delay. Serve notices as early as possible.

3. Confusing the Party Wall Act with planning permission. The Party Wall Act is completely separate from planning permission and building regulations. You can have full planning approval and still need party wall notices. And consent under the Party Wall Act does not give you planning permission.

4. Thinking dissent means the work cannot proceed. A dissenting neighbour triggers the surveyor process — it does not stop the work. The Party Wall Act gives you the right to do the work; dissent simply means the terms need to be agreed by surveyors.

5. Not getting a schedule of condition. Even if your neighbour consents, consider getting a photographic schedule of condition. If damage occurs later and there is no record of the property’s state before work started, disputes become much harder to resolve.

1. Check if the Party Wall Act applies — if your extension is on or near a boundary, or your foundations are within 3–6 metres of a neighbouring building, it almost certainly does
2. Talk to your neighbour before serving formal notices
3. Serve notices early — at least 1–2 months before work starts
4. Check if your extension is permitted development — planning and party wall are separate processes, but you may need both