Party Wall Agreement London | Do I Need a Notice? 2026

You need a party wall agreement whenever your refurbishment cuts into, builds on or alters a wall you share with a neighbour, or involves excavating near their foundations. The Party Wall etc. Act 1996 requires you to serve written notice first: two months for work to a party wall, one month for excavation close to a neighbour's building. In a London terrace, that captures chimney breast removals, inserting steel beams into a party wall and many loft and rear works. This guide explains exactly when the Act applies, what it costs and what happens if you ignore it.

What is the Party Wall etc. Act 1996?

The Party Wall etc. Act 1996 is the law that governs work to walls and structures shared with a neighbour. It exists to let you carry out legitimate building work while protecting the adjoining owner from damage and giving them a clear, fair process if a dispute arises. A party wall is any wall that stands on the boundary between two properties or separates two owners' buildings, which in a London terrace usually means the walls dividing you from the houses on either side. The Act also covers party fence walls (a garden wall on the boundary) and party structures such as the floor and ceiling between flats. Crucially, the Act is a separate process from planning permission and building control. You can have full planning consent and approved building regulations and still be breaking the law if you start party wall work without serving notice. The two systems run in parallel, and a good contractor flags the party wall question at survey, long before any tools come out.

When does the Act apply to a refurbishment?

Three categories of work trigger the Act, and most London refurbishments touch at least one of them. First, work directly to a party wall: cutting into it to take the bearing of a new steel beam (an RSJ), removing a chimney breast that is built into the shared wall, raising or thickening the wall, underpinning it, or cutting a damp-proof course into it. This is the most common trigger in terraced and semi-detached homes. Second, building a new wall on or up to the boundary line. This applies to extensions and some outbuildings rather than internal refurbishment, but it is worth knowing if your project grows. Third, excavation near a neighbour's building. If you dig foundations within three metres of their structure and to a lower depth than their foundations, or within six metres and below a line drawn at 45 degrees from the base of their foundations, the Act applies. This catches basement works, some extension footings and underpinning. If your refurbishment is purely cosmetic, redecoration, a new kitchen or bathroom in the same footprint, new flooring, replastering, then the Act does not apply, because nothing structural touches the shared wall.

Type of work	Notice required	Typical timeline before works
Cutting a steel beam (RSJ) into a party wall	Party structure notice	2 months
Chimney breast removal in a party wall	Party structure notice	2 months
Raising, thickening or underpinning a party wall	Party structure notice	2 months
Excavation within 3m and below neighbour's foundations	Adjacent excavation notice	1 month
Excavation within 6m below a 45° line from foundations	Adjacent excavation notice	1 month
Cosmetic refurb not touching the shared wall	None	—

Notice periods: two months and one month

The Act sets two statutory notice periods, and getting them wrong is one of the most common ways London refurbishments slip behind schedule. For work to a party structure, the wall itself, you must serve a Party Structure Notice at least two months before work begins. This covers the RSJ insertions, chimney breast removals and wall alterations that dominate terraced-house projects. For adjacent excavation, digging near a neighbour's foundations, you must serve notice at least one month before work begins. The clock only starts when the neighbour actually receives valid notice, so build the notice period into your programme from the outset rather than treating it as an afterthought. A neighbour has fourteen days to respond. If they consent in writing, you can proceed once the notice period expires. If they dissent, or simply do not reply within fourteen days, a dispute is deemed to exist under the Act and surveyors must be appointed. We always advise serving notice the moment the design is fixed, because two lost months at the start of a project is two months you never get back.

What a party wall surveyor and award do

When a neighbour dissents, the Act requires surveyors to resolve the matter through a document called a Party Wall Award. This is not a court process and it is not adversarial in the way the name suggests; it is a structured way to agree how the work proceeds safely. Each owner can appoint their own surveyor, or both can agree on a single 'agreed surveyor' to act impartially for both sides, which is cheaper and usually quicker. The surveyor's job is to prepare a schedule of condition recording the state of the neighbour's property before work starts (with photographs), set out how and when the work may be done, decide on protective measures, and provide a mechanism for resolving any damage claims afterwards. The Award is legally binding on both owners. It protects you as much as the neighbour: if a crack appears that the schedule of condition shows was already there, you are not liable for it. That schedule is the single most valuable document in the process, and it is the reason serving notice properly is in your own interest, not just a box-ticking obligation.

How much does a party wall agreement cost?

For a typical London refurbishment, budget £700–£1,500 per adjoining owner where a surveyor is involved, though complex projects or central boroughs can run higher. The cost depends on the route. If your neighbour consents to your notice in writing, the process costs you almost nothing beyond your time, no surveyor is needed at all. If they dissent and you use a single agreed surveyor, you pay one fee covering the schedule of condition and the award, usually £700–£1,200. If each side appoints its own surveyor, you typically pay both sets of fees (the building owner customarily covers the adjoining owner's reasonable surveyor costs), which is why two separate surveyors push the figure to £1,500 or more per neighbour. In a mid-terrace house with neighbours on both sides, that can mean two separate party wall procedures. We factor these fees into refurbishment budgets from day one and recommend holding them within your contingency, because they are predictable enough to plan for but easy to forget.

Scenario	Typical cost per neighbour
Neighbour consents in writing	£0 (your time only)
Single agreed surveyor	£700 – £1,200
Each owner appoints own surveyor	£1,200 – £1,500+
Drafting and serving notice (surveyor-prepared)	£100 – £200

What happens if you skip the party wall process?

Skipping notice does not make the Act go away; it removes your protections and hands the advantage to your neighbour. If you start notifiable work without serving notice, the neighbour can apply to the county court for an injunction stopping your work. An injunction halts the whole site, not just the party wall element, and you bear the legal costs and the delay. We have seen refurbishments frozen mid-programme for exactly this reason. You also lose the schedule of condition. Without that dated, photographed record agreed before work, any crack, settlement or damage the neighbour notices becomes your problem to disprove, and the legal presumption is not in your favour. Disputes that should have cost a few hundred pounds to avoid turn into thousands in claims and surveyor fees after the fact. Finally, an unagreed party wall matter can surface years later when you sell. Buyers' solicitors ask whether party wall procedures were followed, and a missing award can stall or sink a sale. The honest position is simple: serving notice costs little and protects you; skipping it saves nothing and exposes you on every front.

Common London terraced-house scenarios

Most party wall questions we field come from a handful of recurring jobs in period London housing. Chimney breast removal is the classic case. The breast is built into the party wall, so removing it on the ground or first floor, and installing a gallows bracket or beam to support the stack above, is notifiable work requiring a two-month Party Structure Notice. It also needs building control sign-off for the support, which is a separate matter. Steel beams for open-plan layouts are next. Knocking through to create a kitchen-diner usually means an RSJ whose end bearing is cut into the party wall, and cutting into the wall triggers the Act. Where the beam sits within your own internal walls and does not touch the shared wall, it may not. Loft conversions frequently raise the party wall (and need notice), while basement digs almost always trigger the adjacent excavation provisions. Even something as ordinary as fitting new wall plates or padstones into the party wall counts. When in doubt, we assess it at survey, because the cost of asking is nothing and the cost of guessing wrong is an injunction.

Frequently Asked Questions

Do I need a party wall agreement to remove a chimney breast in a London terrace?

Yes, in almost all cases. The chimney breast is built into the party wall you share with the neighbouring house, so removing it and supporting the stack above is work to a party structure. You must serve a Party Structure Notice at least two months before work starts, and the support also needs building control approval.

How long does a party wall agreement take?

Allow two months for a party structure notice and one month for adjacent excavation before work can begin, plus the neighbour's fourteen-day response window within that period. If the neighbour consents in writing you can proceed once the notice period ends; if they dissent, appointing surveyors and producing the award typically adds a further two to four weeks. Serving notice the moment the design is fixed avoids these delays holding up your start date.

How much does a party wall surveyor cost in London?

Expect £700–£1,500 per adjoining owner where a surveyor is needed. A single agreed surveyor acting for both sides costs roughly £700–£1,200, while each owner appointing their own surveyor pushes it to £1,200–£1,500 or more. If your neighbour simply consents to your notice in writing, no surveyor is required and the cost is effectively nil.

Do I need a party wall notice if I'm only inserting an RSJ?

It depends on where the steel bears. If the beam's end is cut into the party wall to take its load, the Act applies and you must serve a two-month Party Structure Notice. If the RSJ sits entirely within your own internal walls and does not cut into or rest on the shared wall, notice is usually not required. We confirm which applies at survey before any structural work is planned.

What if my neighbour ignores the party wall notice?

If a neighbour does not respond within fourteen days, the Act treats this as a dissent and a dispute is deemed to exist, which means surveyors must be appointed to produce a Party Wall Award before work can proceed. You cannot simply carry on because they stayed silent. The award process protects both of you, and serving notice early leaves time for it to run without delaying your build.

Party Wall Agreements for London Refurbishments: Do You Need One?