The Party Wall Act for homeowners: what to expect

If you live in a terraced or semi-detached house, almost any extension, loft conversion or basement will involve the Party Wall etc. Act 1996. The Act is not about planning permission. It is a framework for doing work that affects a wall or foundations you share with a neighbour, in a way that protects both of you. This guide explains which work it covers, how the notice process works, what happens if your neighbour does not agree, and how to keep things friendly.

What the Act covers

The Act applies in England and Wales and covers three kinds of work. The first is work to an existing party wall or party structure, such as cutting into it to support steel beams, raising its height, thickening it, underpinning it, or removing a chimney breast that is attached to it. The second is building a new wall on or at the boundary line between two properties. The third is excavating near a neighbour's building: within 3 metres of it and deeper than its foundations, or within 6 metres where the dig would cut a line drawn down at 45 degrees from the bottom of their foundations.

In practice, that means most loft conversions on terraced and semi-detached houses (where new steels usually bear on the party wall), many rear and side-return extensions (where foundations are dug close to the neighbour, or a wall is built on the boundary) and almost every basement are covered. Our loft conversions, house extensions and basement conversions pages explain where it fits into each project.

Who is who

The Act uses its own terms. You, the person doing the work, are the building owner. Your neighbour is the adjoining owner. Adjoining owners include anyone with a legal interest in the neighbouring property, so if the house next door is divided into flats, or has a leaseholder and a freeholder, several people may need to be notified.

Serving notice

Before any notifiable work starts, the building owner must serve written notice on each adjoining owner, describing the work and when it will start. At the time of writing, the minimum notice periods are two months for work to a party wall, and one month for a new wall on the boundary or for excavation near a neighbour's foundations. Notices for excavation should include drawings showing the position and depth of the new foundations.

Many homeowners have a party wall surveyor prepare and serve the notices, but you can serve them yourself if you use the correct form. The government's Party Wall guidance explains what a valid notice needs to contain. Notices that are incomplete or served on the wrong people can cause delays later, so it is worth getting them right.

How your neighbour can respond

Once notice is served, your neighbour has 14 days to respond. They can give written consent, in which case the work can go ahead once the notice period has passed. They can dissent, which puts the matter into a formal dispute resolved by surveyors. Or they can fail to reply, and for most notices, no reply within 14 days is treated as a dispute as well.

"Dispute" sounds alarming, but it is simply the Act's term for the surveyor route, and it is very common. Many neighbours are perfectly happy with the work but prefer to have a surveyor record the condition of their property and agree how the work will be done.

Party wall surveyors and the award

In a dispute, there are two ways to appoint surveyors. Both owners can agree on a single surveyor who acts impartially for both of them, which is usually quicker and simpler. Alternatively, each owner appoints their own surveyor, and those two surveyors select a third surveyor who can step in if they cannot agree.

The surveyors produce a party wall award: a legal document that sets out the work that can be done, how and when it will be carried out, any precautions, access arrangements and who pays for what. It normally includes a schedule of condition, a record of the neighbour's property, often with photographs, taken before work starts, so any damage can be identified fairly afterwards. Surveyors must act impartially, whoever appointed them.

The building owner usually pays the reasonable costs of both surveyors, because the work is being done for their benefit. Either owner can appeal an award to the county court, but only within 14 days of receiving it.

Access and protecting both sides

The Act gives the building owner a right to access the neighbour's property where that is necessary to carry out the permitted work, normally with 14 days' notice, for example to put up scaffolding or make good a wall. The award will usually say how access is to be arranged. In return, the building owner must avoid unnecessary inconvenience and make good, or pay for, any damage the work causes.

In some cases the adjoining owner can ask for security for expenses: a sum held in case the work is left unfinished or causes loss. This is more common on larger projects such as basements.

Where it comes up locally

In South West London, party wall work is part of the local character. Wandsworth's guidance for mid-terrace loft conversions favours raising the party walls to build a full-width mansard-style extension, which is why so many lofts in Southfields and Wandsworth Town involve party wall notices. Basements are another trigger: in Fulham and Richmond, every basement needs planning permission, and the council's basement policies require construction management plans that go hand in hand with the party wall process. On the conservation streets of Merton Park, work to shared boundaries and front walls is also closely controlled.

What happens if you ignore it

Starting notifiable work without serving notice is a serious mistake. Your neighbour can seek a court injunction to stop the work, which can halt a project midway, and you lose the protection that a proper award gives you if damage is later alleged. It can also cause problems when either property is sold. The notice process takes some planning, but it is far less disruptive than a dispute after work has started.

Keeping it friendly

The best party wall processes start with a conversation. Talk to your neighbours before notices arrive, show them the drawings, explain the timetable and give them a contact on site. Neighbours who feel informed are far more likely to consent, or to agree to a single surveyor, and a good relationship makes the whole build easier. Build the notice periods into your programme from the start, so the Act never becomes the thing that delays the job.