Party Wall Agreements in London: A Complete Guide

The Party Wall etc. Act 1996 is a piece of legislation that surprises many homeowners undertaking building works for the first time. If your project involves work to a shared wall, close to a boundary, or excavation near a neighbouring property, the Act applies and formal notices must be served on your neighbours. Getting this wrong can stop a project mid-construction.

When Does the Party Wall Act Apply?

The Act applies when you intend to:

• Work on an existing wall or structure shared with another property (a "party wall")
• Build on or at the boundary with a neighbouring property
• Excavate within 3m of a neighbouring structure where the excavation goes deeper than their foundations, or within 6m where the excavation extends below a 45-degree line from their foundation base

Most extension projects in London trigger at least one of these conditions.

Party Wall Notice

Before starting notifiable work, you must serve a Party Wall Notice on each affected neighbour. There are different notice types:

• Party Structure Notice: For work to a party wall or party fence wall (typically 2 months' notice required)
• Line of Junction Notice: For building on or astride a boundary (typically 1 month's notice required)
• Three Metre Notice / Six Metre Notice: For excavations close to neighbouring structures

Notices can be served personally, by post, or through a party wall surveyor.

Neighbour Responses

A neighbour who receives a party wall notice has 14 days to respond:

• Consent: The neighbour consents to the works. No party wall award is required.
• Dissent (or no response): If the neighbour dissents or fails to respond within 14 days, a party wall award must be agreed. Each party appoints a surveyor (or they agree on a single "agreed surveyor") and the award is negotiated.

The Party Wall Award

The party wall award is a legal document that sets out:

• What works may be carried out
• When and how the works may be carried out
• Access rights to the neighbouring property
• A schedule of condition of the neighbouring property before works start

The award is binding on both parties.

Cost of Party Wall Surveyors

Party wall surveyors typically charge £800–£2,500+ per surveyor depending on complexity. If each party appoints their own surveyor, the building owner (the party doing the work) typically pays both surveyors' fees.

Programme Implications

Serve party wall notices as early as possible. The statutory notice periods and the time required to agree an award can add 2–3 months to the pre-construction phase if not planned for.

RCB Design & Build

RCB Design & Build advises clients on party wall obligations as part of the pre-construction review and can recommend experienced party wall surveyors where required.