What is a party wall agreement and when do you need one?

A party wall agreement is a legal document created when one property owner plans to carry out building work on or near a shared wall, floor or boundary. It records that the adjoining property owner has been properly notified and sets out the agreed terms for how the work will be carried out.

A party wall is any wall, floor or structure shared between two properties. This includes walls that sit on the boundary between two buildings, walls that form part of one building but are adjacent to another, and floors and ceilings between flats.

Party walls are governed by the Party Wall etc. Act 1996. The Act sets out the rights and responsibilities of property owners when building work affects a shared structure.

You will need a party wall agreement if you are planning work that affects a party wall or boundary. Common examples include building an extension, underpinning foundations, cutting into a party wall to install beams or services, excavating near the boundary, or raising the height of a shared wall.

Under the Party Wall Act, a party wall notice must be served on all adjoining owners of affected properties at least two months before work begins. The notice must set out the nature and extent of the proposed work in sufficient detail. Once the notice has been served, adjoining owners have 14 days to respond.

If an adjoining owner gives written consent, work can proceed without a formal award. If they do not respond to the notice or dispute the work, a party wall surveyor must be appointed. In straightforward cases both parties may agree to use a single agreed surveyor. Where they cannot agree, each party appoints their own party wall surveyor, and the two surveyors may then appoint a third to resolve any dispute.

The agreement sets out the details of the proposed work, including working hours, how the party wall will be accessed and any protective measures required. It also includes a schedule of condition: a photographic and written record of the state of adjoining properties before work begins. This protects both parties if there is any dispute about damage caused during the works.

When buying a property, it is worth understanding the party wall position before you exchange. Your conveyancing solicitor's searches will reveal any party wall notices already served in connection with neighbouring properties. A property survey will also identify any party walls and flag anything relevant for your solicitor to investigate further.

If a neighbour is already planning work that will affect the property you are buying, you need to know about it before you commit. Once you have purchased the property, you inherit the situation, including any ongoing disputes or planned works.

If you are buying a property and planning to carry out structural work after purchase, understanding which walls are party walls will affect your planning timeline. Any work requiring a party wall agreement cannot start until the notice period has been served and either consent received or an award agreed, which typically adds two to three months to the process.

If you are considering converting a loft, adding a home office or making other structural changes to accommodate working from home, party wall obligations are likely to apply. It is worth taking advice early in your plans, as the notice and agreement process needs to be factored into your project timeline.

A RICS Level 2 HomeBuyer Report or RICS Level 3 building survey will identify shared walls and any visible evidence of previous or ongoing building works that may be relevant to the party wall position. The survey report will flag anything that your conveyancing solicitor should investigate further.

For more information on what each survey level covers and costs, see our survey cost page.

At Surveyor Local, we work exclusively with RICS-accredited chartered surveyors across England and Wales. Our team can arrange a survey quickly and at a competitive price.

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