Party walls

Party walls and protection of neighbouring properties

Contractors must carry out their own checks, with support from a structural engineer where needed, to understand the location and condition of any nearby structures before starting work. They must protect the stability and condition of all buildings and services that could be affected, including public utilities and rail infrastructure.

They must also take steps to reduce noise and vibration. This includes limiting vibration through structures and ground movement that could affect nearby properties or cause damage.

Risks from ground movement, such as settlement or heave caused by excavation or other works, must also be properly managed.

Guidance on the Act and your responsibilities

• The Party Wall etc. Act 1996 (gov.uk)

Advice to builders and residents

The Party Wall etc. Act 1996 will apply where any excavation is:

• within 3m of a neighbouring structure and extends deeper than that structure’s foundations; or
• within 6m of a neighbouring structure and to a depth below a line drawn down at 45^o from the underside of that structure;
• associated with the intention to underpin or carry out works to a party wall between two properties.

If any of these conditions apply, especially where basements or sub‑basements are being built, contractors must notify neighbouring property owners and explain the work.

Neighbouring owners have the right to:

• ask for protective measures
• avoid unnecessary disruption
• receive compensation for any loss or damage
• request financial security in case work stops at a critical stage

The contractor and the neighbouring owner will usually agree a record of the building’s condition before work starts. This should include photos. A follow-up survey may be needed after the work is complete, for up to two years after the building is occupied.

The Council recognises that some building work can cause cracking or damage through vibration. These risks must be managed through a Party Wall Agreement.

Contractors should bear in mind that complaints relating to vibration and excavation in close proximity to existing structures with the possible destabilising of neighbouring foundations, can lead to considerable delays while the problems are resolved. These may arise particularly during the demolition, piling and ground work phases.

The Council of The Royal Borough is not involved in the preparation, review or monitoring of any Party Wall Agreement.

Where party wall issues are likely, it is standard practice to appoint a chartered surveyor or engineer to advise on protecting neighbouring buildings.

Developers and contractors should seek professional advice on the Party Wall etc. Act. They should also consult fully with neighbouring owners and occupiers to discuss the work, avoid damage, and reduce disruption.