Party Wall Agreements — Everything You Need to Know Before Building

A party wall is a wall shared by two properties. It includes:

• •A wall that stands on the boundary line of two properties (a 'party wall' in the strict sense)
• •A wall that forms part of one building but stands on the land of two different owners
• •A garden wall or fence on the boundary (a 'party fence wall')
• •A floor or ceiling between flats

Party wall matters arise most commonly in terrace and semi-detached houses during loft conversions, rear extensions, and structural alterations.

The Party Wall etc. Act 1996 applies when you intend to carry out any of the following:

1. Work on an existing party wall or party fence wall — inserting a damp proof course, cutting into the wall for beams (known as 'flashing'), making openings, or any work that will affect the wall's structural condition

2. Building a new wall on the boundary line or on your own land up to or astride the boundary

3. Excavating within 3 metres of a neighbour's building (if your excavation goes deeper than the neighbour's foundations), or within 6 metres if following a 45-degree line from the bottom of a neighbour's foundations

Loft conversions commonly involve inserting steel beams ('padstones') into the party wall. Rear extensions often involve excavating foundations within 3 metres of a neighbour. Both trigger the Act.

You must give written notice to each adjoining owner before starting the relevant work. The notice must:

• •Be served in writing (by hand, post, or — with agreement — email)
• •Include your name and address
• •Include the address of the building where work will be carried out
• •Describe the proposed work with enough detail for the neighbour to understand what is involved
• •State when you intend to start

• Different notice periods apply:
• •Line of junction notices (new walls): at least 1 month before work starts
• •Party structure notices (work on existing party walls): at least 2 months before work starts
• •Adjacent excavation notices: at least 1 month before work starts

RCB provides party wall notice templates as part of our pre-construction service.

Your neighbour has 14 days to respond after receiving a party wall notice. They can:

1. Consent in writing — work can proceed after the notice period expires 2. Dissent and agree to appoint a single 'agreed surveyor' jointly 3. Dissent and appoint their own surveyor 4. Fail to respond — after 10 days of no response, they are deemed to have dissented and you must appoint a surveyor

A response of 'consent' is the most straightforward outcome. Where a neighbour dissents, a Party Wall Award must be produced before work can start.

Party wall surveyors are appointed to produce a Party Wall Award — a formal document that records the condition of the neighbour's property before works start ('schedule of condition'), sets out when, how and in what manner the work may be carried out, and provides a mechanism for making a compensation claim if damage occurs.

Where both parties appoint their own surveyor, the two surveyors must agree on the Award. Where a single 'agreed surveyor' is appointed, one surveyor acts for both parties. The building owner (the person doing the work) pays the surveyor's fees.

Party wall surveyors do not need to be members of any specific organisation, but qualifications from RICS (Royal Institution of Chartered Surveyors), FPWS (Faculty of Party Wall Surveyors) or the Pyramus & Thisbe Club are signs of competence.

A schedule of condition is a photographic and written record of the condition of the adjoining property before work starts. It documents existing cracks, settlement, damp patches, and other defects. It is prepared by the party wall surveyor as part of the Award process.

The schedule of condition is important because it establishes a baseline. If your neighbour claims damage caused by your work, the schedule confirms what damage existed before and what is new. Without it, any dispute about who caused what becomes very difficult to resolve.

Your neighbour cannot simply 'refuse' — the Act does not give them a veto. If they dissent, a Party Wall Award is produced, and provided the Award permits the work, you can proceed. The Award sets conditions but cannot prevent you from lawfully exercising your rights under the Act.

If a neighbour physically obstructs your work, you can seek an injunction from the court. If the Award is disputed, either party can appeal to the County Court within 14 days of the Award being served.