Party Wall Agreements Demystified

The Party Wall etc. Act 1996 governs work to shared walls, boundaries, and excavations near neighbouring buildings. Many homeowners trigger its requirements without realising it — and failing to follow the correct procedure can lead to injunctions stopping your project and significant legal costs.

The Act applies to three types of situation: work on a shared (party) wall or structure between two properties; building a new wall on or at the boundary of two properties; and excavations within 3 metres of a neighbouring structure (6 metres if the excavation is deeper than the neighbouring foundations). Extensions, loft conversions involving the party wall, and basement conversions are the most common triggers.

You must serve written notice on all adjoining owners before starting work. The notice period is 1 month for party wall work, and 2 months for new building at the boundary or deep excavations. Notices should describe the work and include a plan where appropriate. You can use a template from the government's website or ask a party wall surveyor to serve notice on your behalf.

The Party Wall Act is a dispute resolution mechanism — it is not about preventing work, but about providing a framework for neighbouring owners to understand and respond to proposed works.

— RICS (Royal Institution of Chartered Surveyors)

If your neighbour agrees in writing to the works within 14 days of the notice, you can proceed without needing a party wall award. This is the simplest outcome and costs nothing beyond the notice itself. Always keep the consent letter in a safe place — you may need it when selling the property.

If your neighbour objects or does not respond within 14 days, a dispute is deemed to exist. Both parties must then appoint party wall surveyors — either a single agreed surveyor or one each. The surveyors produce a Party Wall Award (also called an agreement) that describes the works, records the condition of the neighbouring property before works begin, and sets out the rights of both parties. The cost of the surveyors is typically borne by the building owner.

• Party wall notice: must be served 1-2 months before work starts
• Consent period: 14 days for neighbours to respond
• Single agreed surveyor: lowest cost option if both sides agree
• Separate surveyors: each party appoints one
• Party wall award: legally binding on both parties