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What Is a Party Wall? — Party Wall Act Explained
A plain-English guide to party walls: the Party Wall etc. Act 1996, notice requirements, party wall surveyors, and your rights and obligations in England and Wales.
Definition
A party wall is a wall that stands on the land of two or more owners and forms part of a building. This includes walls that separate adjoining terraced or semi-detached houses, and garden walls built on the boundary line. The Party Wall etc. Act 1996 provides a framework for preventing and resolving disputes in relation to party walls, boundary walls, and excavations near neighbouring buildings in England and Wales.
When Is It Used?
The Party Wall Act is triggered by three types of work: building on the boundary (Section 1), work to an existing party wall or party structure such as cutting in a beam, raising the wall, or underpinning (Section 2), and excavation within 3 or 6 metres of an adjoining owner's foundations (Section 6). Common domestic projects that trigger the Act include loft conversions with work to the party wall, rear extensions near the boundary, and basement excavations.
Key Facts
- The Party Wall etc. Act 1996 applies in England and Wales only (Scotland has different rules)
- Three types of notice: Line of Junction (Section 1), Party Structure (Section 2), and Adjacent Excavation (Section 6)
- Neighbours have 14 days to respond to a notice with consent or dissent
- A Schedule of Condition records the state of the neighbour's property before work begins
- The building owner is responsible for making good any damage caused by the work
- The building owner pays all reasonable surveyor fees, including the adjoining owner's surveyor
- A Party Wall Award is legally binding and can be enforced through the county court
- Work can proceed once the Award is served, even if the adjoining owner disagrees (they can appeal within 14 days)
Related Calculators
Use the Foundation Calculator for excavation depth planning, or the Brick Calculator for party wall construction. The Project Profit Calculator helps budget for party wall surveyor fees.
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Frequently Asked Questions
You must serve notice if you plan to: build on or at the boundary with a neighbouring property, carry out work to an existing party wall or party structure (including cutting into the wall, raising it, or demolishing and rebuilding it), or excavate within 3 metres of a neighbouring building's foundations to a depth below the bottom of those foundations (or within 6 metres at a 45-degree angle). Common triggers include loft conversions, rear extensions, and basement excavations.
For work to an existing party wall or party structure, you must give at least 2 months' notice. For new building work at or on the boundary line, you must give at least 1 month's notice. For excavation work near a neighbour's foundations, you must give at least 1 month's notice. The neighbour then has 14 days to respond with consent or dissent.
If your neighbour dissents (or fails to respond within 14 days, which is treated as dissent), the matter goes to a party wall surveyor dispute resolution process. Each party appoints their own surveyor, or both parties can agree to appoint a single "agreed surveyor." The surveyors prepare a Party Wall Award that sets out the work to be done, conditions, and any compensation. The building owner typically pays all surveyor fees.
If your neighbour consents, no surveyor is needed and there are no costs beyond the notice letter. If surveyors are required, expect to pay £800-£1,500 per neighbour for straightforward cases (e.g., a rear extension). Complex cases involving basement excavation or multiple adjoining owners can cost £2,000-£5,000 or more. The building owner (the person doing the work) pays both surveyors' fees.
It is not a criminal offence to proceed without serving notice, but it is a civil matter. Your neighbour could seek an injunction to stop the work, and you would be liable for any damage caused. Courts take a dim view of building owners who fail to serve notice. It is strongly recommended to follow the Act properly, as the process protects both parties and provides a clear record of the condition of the neighbour's property before work begins.
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Last updated: March 2026
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