Party Wall Services. Handled by Professional Surveyors.
You need to serve a Party Wall Notice if your building work falls into one of three categories under the Act: work to a shared (party) wall or structure, building a new wall on or at the boundary, or excavating near a neighbour’s foundations. Common examples that almost always need a notice are loft conversions, rear and side extensions, basements, chimney breast removals and underpinning.
If your works are purely internal, cosmetic, or nowhere near a shared wall or boundary, you usually do not. When in doubt, a quick look at your drawings settles it, and serving when you did not strictly need to is far cheaper than not serving when you should have.
A Party Wall Notice is the formal, written notice you must give your neighbours before starting certain building works, under the Party Wall etc. Act 1996. It tells the affected neighbour (the Adjoining Owner) what you intend to do, where, and when, and it gives them the chance to agree or to have a surveyor protect their interests.
The person carrying out the works is the Building Owner. Anyone who shares the wall or boundary, or whose property sits close to the excavation, is an Adjoining Owner. An owner can be a freeholder or a leaseholder with more than a year left on the lease, so a single neighbouring property, especially a flat, can have more than one owner who must be served.
Serving notice is not asking permission. It is a legal step that starts a clear, time-limited process designed to let your works go ahead while protecting the building next door.
The Act covers three distinct types of notifiable work. Each has its own notice and its own minimum notice period before works can begin.
| Notice | When it applies | Typical works | Notice period |
|---|---|---|---|
| Line of Junction Notice Section 1 |
Building a new wall on, or up to, the boundary line where none exists. | A new garden or boundary wall, or the flank wall of an extension built to the boundary. | At least 1 month |
| Party Structure Notice Section 2 / 3 |
Work to an existing shared wall or structure. | Cutting in for steel beams, raising, thickening or underpinning the wall, removing a shared chimney breast, or demolishing and rebuilding it. | At least 2 months |
| Notice of Adjacent Excavation Section 6 |
Digging near a neighbour’s building, below the level of their foundations. | Foundations for an extension, a basement dig, or underpinning within the 3 metre or 6 metre zones (explained below). | At least 1 month |
A single project can need more than one notice. A rear extension, for example, often needs a Section 6 excavation notice and a Section 1 line of junction notice at the same time. Each qualifying neighbour must be served with the notices that affect them.
Most jobs fall clearly on one side of the line. Here are the projects we are asked about most often.
Not sure which side you are on? The safest approach is to have the drawings checked before you commit. A short review confirms whether the Act applies and which notices are needed, well before your builder is booked.
Section 6 catches far more projects than people expect, because it is about proximity and depth, not about touching the wall at all. Two tests decide whether excavation is notifiable:
Because most London homes are Victorian or 1930s with shallow foundations, a standard extension footing or a basement dig frequently falls inside these zones even on a wider plot. This is the single most common reason a project turns out to be notifiable when the owner assumed it was not.
Serving the notice starts a fixed timetable. Your neighbour has 14 days to respond in one of three ways.
The works can proceed once the notice period has passed. No Party Wall Award is needed, though a Schedule of Condition recording their property is still strongly advisable to protect both sides.
A dispute is deemed to have arisen under the Act. Surveyors are appointed, either one Agreed Surveyor acting impartially for both owners, or one for each owner, and they prepare a Party Wall Award.
This is treated as dissent, known as deemed dissent. A further request gives them 10 days to appoint a surveyor. If they still do not, you may appoint one on their behalf so the process can continue.
Timing matters. A Party Structure Notice needs 2 months, and Line of Junction and Excavation notices need 1 month, before works can start. A served notice is valid for 12 months, so serve early: right after your design is settled, not the week before you break ground.
It does not. Planning, building regulations and the Party Wall Act are three separate approvals. You can hold full planning consent and still be required to serve notice.
They cannot. The Act is designed to let notifiable works proceed. Dissenting only triggers a Party Wall Award that sets out how the works are done and how their property is protected.
A friendly chat is good practice, but only a valid written notice starts the legal process and protects you. A verbal agreement carries no weight under the Act.
If you carry out notifiable work without serving a valid notice, you are acting outside the Act. Your neighbour can apply to the County Court for an injunction to stop the works, which can halt your project at short notice and at considerable cost.
You also lose the protection the process gives you. Without an agreed Schedule of Condition recording the neighbouring property beforehand, any claim that your works caused damage becomes far harder to resolve, and you carry the risk. Serving correctly is quicker, cheaper and safer than dealing with a dispute after the event.
Yes. There is no legal requirement to use a surveyor to serve a notice, and free templates are available in the government’s explanatory booklet. However, a notice with the wrong details, the wrong owners or the wrong sections is invalid, which restarts the clock and can delay your build. Many owners have a surveyor prepare and serve the notices to avoid that risk.
It depends on the notice. A Party Structure Notice requires two months, while Line of Junction and Adjacent Excavation notices require one month. If your neighbour consents in writing sooner, you can usually start once the notice period ends. Build the notice period into your programme from the outset.
If your neighbour consents, serving the notices is inexpensive. If they dissent and a Party Wall Award is needed, the Building Owner normally pays the reasonable surveyor fees for both sides, because the works are for the Building Owner’s benefit. Costs rise with the number of neighbours and the complexity of the works.
The notice is the formal warning of your intended works. If the neighbour consents, that written consent is the informal “agreement”. If they dissent, surveyors produce a Party Wall Award, the binding legal document that regulates how the works are carried out. Our guide on party wall notice vs Award explains this in full.
In most cases, yes. A loft conversion usually bears steel beams on the party wall or raises it to form a gable, and an extension usually excavates within three metres of a neighbour’s foundations. Both are notifiable. See our guides on loft conversions and extensions.
If there is no response within 14 days, a dispute is deemed to have arisen. You then serve a further request giving them 10 days to appoint a surveyor. If they still do not, you can appoint a surveyor on their behalf so the process, and your project, can move forward.
Send us your drawings or a short description of the works. A LENIO chartered surveyor will confirm whether the Party Wall etc. Act 1996 applies, exactly which notices you need and when they must be served, with free initial advice and no obligation.
