When a party wall notice is required for an extension
Extensions require party wall notices in several scenarios. (1) Party Structure Notice: required when you are building directly on a party wall — e.g. inserting a steel beam into a party wall to carry the rear extension above. This is the most common situation for London rear extensions. (2) Three Metre Notice: required when you are excavating foundations within 3m of a neighbour's foundation, measured horizontally. Almost all rear extensions in London require this because London terraces are closely spaced. (3) Six Metre Notice: required where foundations are deeper than your neighbour's by more than the horizontal distance to the boundary — less common, applies on some clay substrates requiring deep foundations.
What a party wall notice must contain
The party wall notice must include: your name and address; the address of the property where work is being done; a clear description of the proposed work; the proposed start date (at least 2 months hence for structural work, 1 month for excavation); a statement that the notice is served under the Party Wall Act 1996. It must be given in writing and can be hand delivered, posted or sent by email (if the neighbour has agreed to email communication). There is no prescribed form but the government publishes an example notice at gov.uk. Builderr prepares and serves party wall notices as part of our standard project management — no separate charge.
