Not every building project requires a party wall surveyor, but many London home improvements do. This guide from our RICS-accredited team helps you work out whether your works are notifiable, when a surveyor is genuinely needed, and what happens if you skip the process.
Start with the works, not the surveyor
The first question is whether your project involves notifiable works under the Party Wall etc. Act 1996. If it does, you must serve notice on affected neighbours. A surveyor only becomes necessary if a neighbour dissents, or if you simply want expert help to get the process right.
Common projects and whether a notice is needed
| Project | Typically notifiable? | Why |
|---|---|---|
| Loft conversion cutting into the party wall | Yes | Inserting beams or steels into a shared wall (Section 2) |
| Rear or side extension near the boundary | Often | Excavation within 3m below neighbour’s foundations (Section 6) |
| Basement excavation | Yes | Deep excavation within 3m or 6m of neighbouring structures |
| Removing a chimney breast on a party wall | Yes | Cutting into the party structure |
| New garden wall on the boundary line | Yes | Building on the line of junction (Section 1) |
| Internal, non-structural redecoration | No | No work to the party wall or nearby excavation |
| Fitting shelves or a wall-mounted TV | No | Minor works are outside the Act |
These are general indications only. Whether a specific project is notifiable depends on the detail of the design and the proximity of neighbouring structures.
The three triggers under the Act
- Section 1 – building a new wall on or at the boundary line where none exists.
- Section 2 – works to an existing party wall or structure, such as cutting in, raising, underpinning or removing a chimney breast.
- Section 6 – excavating within 3 metres and below the level of a neighbour’s foundations, or within 6 metres where a 45-degree line from the base of their foundations would strike your excavation.
If your works fall under any of these, you must serve the relevant party wall notice on your neighbours before starting.
Do I actually need a surveyor?
Serving notice does not automatically require a surveyor. Once notice is served, each adjoining owner can respond in one of three ways.
- Consent – if all neighbours agree in writing within 14 days, no dispute arises and you may not need a surveyor at all, though a schedule of condition is still wise.
- Dissent and agree one surveyor – the parties jointly appoint a single agreed surveyor, the most economical route.
- Dissent and each appoint a surveyor – two surveyors are appointed, who then produce the award together.
Even where consent is given, many owners engage a surveyor to draft the notice correctly and record condition, reducing the risk of later disputes.
Consequences of not serving notice
Proceeding with notifiable works without serving notice is a serious mistake, even though it is not a criminal offence.
- The adjoining owner can seek an injunction to halt the works until the correct procedure is followed.
- You lose the protection of an agreed schedule of condition, making damage claims far harder to defend.
- The burden of proof on damage can shift against you.
- Relations with neighbours – and any future sale of your home – can be jeopardised.
For a fuller picture of what is involved, see our overview of the costs and process and guidance for building owners.
FAQs
Does a small extension need a party wall notice?
It depends on the foundations. If you excavate within three metres and below the level of your neighbour’s foundations, a Section 6 notice is usually required even for a modest extension.
If my neighbour consents, do I still need a surveyor?
Not necessarily. Written consent means no dispute has arisen, so surveyors need not be appointed. A schedule of condition remains strongly advisable to protect both sides.
What if I have already started work without notice?
Stop and take advice. Your neighbour could seek an injunction. Serving notice and appointing a surveyor promptly is the best way to regularise the position.
Unsure whether your London project needs a notice or a surveyor? Our RICS-accredited team will tell you honestly. Contact us for a quick, no-obligation assessment.