Party wall agreement: a plain-English guide for London homeowners planning building work.

A party wall agreement is the everyday name for the process set out in the Party Wall etc. Act 1996. Before certain work on or near a shared wall or boundary, you must serve notice on the neighbouring owner. They can consent in writing, or, if they refuse or do not reply, surveyors settle the matter in a document called a party wall award. Notice is due at least two months before work to an existing party wall, and at least one month before building a new wall on the boundary or excavating near a neighbour's foundations. This is general information, not legal advice.

What the Party Wall etc. Act 1996 covers

The Act came into force on 1 July 1997 and applies throughout England and Wales; Scotland has different rules (GOV.UK: the Party Wall etc. Act 1996 explanatory booklet). GOV.UK describes a party wall as one that stands on the land of two or more owners and either forms part of a building or does not, such as a garden wall, but not a wooden fence. Walls on one owner's land that another owner uses to separate their building also count, and a floor between flats can be a party structure (GOV.UK: party walls and building work).

The booklet groups notifiable work into three types:

• A new wall at the boundary (section 1). Building a free-standing wall or the wall of a building up to or astride the boundary line.
• Work to an existing party wall or structure (section 2). For example, cutting into a party wall to take the bearing of a beam (for example for a loft conversion), raising its height (for example, adding another storey), underpinning its whole thickness, or demolishing and rebuilding it.
• Excavation near a neighbour's building (section 6). Digging within 3 metres of any part of a neighbouring owner's building or structure where the work will go deeper than their foundations, or within 6 metres where it will meet a line drawn downwards at 45° in the direction of the excavation from the bottom of their foundations.

Minor work is unlikely to need notice. The booklet gives drilling into a party wall to fix plugs and screws for ordinary wall units or shelving, cutting in to add or replace recessed wiring and sockets, and removing old plaster and replastering as examples, and says the key question is whether the work could affect the wall's structural strength or damage the neighbour's side.

The Act is separate from planning permission and building regulations: having either approval does not remove the need to follow it.

Why the Act comes up so often in London

London had its own party wall procedure before the national Act. Before the 1996 Act came into force, party wall procedure in London sat in Part VI of the London Building Acts (Amendment) Act 1939, which was repealed on 1 July 1997 when the national Act took over (The Party Wall etc. Act 1996 (Repeal of Local Enactments) Order 1997). In practice, these are the London jobs where it usually applies:

• Terraced houses. A mid-terrace house shares a wall with the neighbours on both sides, so work to both walls means notices to two owners.
• Loft conversions. Steel beams set into a party wall are the booklet's own example of section 2 work.
• Rear and side extensions. New foundations close to the neighbour's house can fall under section 6, and a wall built on the boundary line under section 1.
• Basements and lowered floors. Excavation below the neighbour's foundation level is classic section 6 work.
• Flats. Floors and walls between flats can be party structures, so the owners above, below or alongside may need notice.

Party wall notice periods

A notice must give your name and address, a full description of the work and when you propose to start. A section 6 notice must also say whether you plan to strengthen or safeguard the neighbour's foundations, with plans and sections attached. The booklet warns that a notice is only valid for a year, so do not serve it too long before you plan to start.

GOV.UK says your neighbour must let you know in writing within 14 days whether they consent, and you cannot assume that no response means they agree. They can consent, refuse, or serve a counter notice asking for additional work to be done at the same time, within a month of your notice (GOV.UK: party walls guide, full version). For section 2 and section 6 work, silence after 14 days means a dispute is deemed to have arisen.

Party wall agreement or party wall award?

If your neighbour consents, GOV.UK says any agreement you reach should be in writing. That written consent is what most people mean by a party wall agreement, and no surveyors are needed.

If they refuse, or do not reply, you must appoint a surveyor. You can appoint one agreed surveyor together, or each appoint your own; if the two appointed surveyors cannot agree, a third surveyor is selected. The surveyors produce a party wall award setting out the work to be carried out and when and how it is to be done; GOV.UK adds that it says who will pay for which part and how much, including surveyors' fees. If your neighbour refuses or fails to appoint a surveyor, you can appoint one on their behalf. You cannot act as your own surveyor.

The booklet says the term "surveyor" can include any person who is not a party to the matter, but that they should have a good knowledge of construction and of the Act, and should not already be supervising the building work. The award is final and binding unless a county court changes it on appeal, and each owner has 14 days from receiving it to appeal.

Who pays?

• The building work. GOV.UK says you pay for any building work you start on a party wall. Your neighbour may have to share the cost if the work is needed because of defects or lack of repair.
• The award. The booklet says the building owner usually pays all costs of drawing up the award, including the neighbour's surveyor's fees where the work is solely for the building owner's benefit.
• Damage. You must protect your neighbour's property and fix or pay for any damage the work causes; adjoining owners have the right to be compensated for loss or damage caused by the works.
• Security for expenses. A neighbour can ask for security for expenses before work starts under the Act.

Surveyors' fees vary by surveyor and job, so ask for a written fee before appointing anyone.

When work starts

Your neighbour must let surveyors and workers in during usual working hours where the work needs it, with 14 days' notice except in an emergency, and you must avoid causing unnecessary inconvenience. The booklet is clear that a neighbour cannot stop someone exercising rights given by the Act, but they may be able to influence how and when the work is done. It is sensible to agree a dated written and photographic record of the neighbour's walls and ceilings before work begins, so any later damage claim can be measured against it.

A practical timeline for a London project

1. Settle the design and check whether you need planning permission or building regulations approval.
2. Work out which type of party wall work it is, and identify every adjoining owner, including both sides of a terrace and the owners above or below a flat.
3. Talk to the neighbours before anything arrives in writing. GOV.UK says you can speak to them to explain the work.
4. Serve notice: at least two months ahead for party wall work, one month for a boundary wall or excavation, and no more than a year before you start.
5. Wait 14 days for a written reply. Get consent in writing, or move to the surveyor route.
6. Book your builder's start date only once consent or an award is in place.

Where Hausio fits

Hausio carries out building works across London, including groundworks and foundation-related work, brickwork and pointing, exterior repairs, glazing, tiling and interior finishes. Hausio is not a party wall surveyor, does not serve notices or prepare awards, and does not give legal advice; serving notice is the building owner's responsibility, and the booklet says the surveyor should not be someone already supervising the building work. When we review a project, we confirm access, materials, sequence and whether specialist approvals are needed, so party wall questions reach the right adviser before a start date is booked. Read more in our guide to building work quotes in London.

This is general information about the Party Wall etc. Act 1996 in England and Wales, not legal advice. The government's booklet itself says only the courts can interpret the law authoritatively. For a specific project, speak to a party wall surveyor or a solicitor.

FAQ

Do I need a party wall agreement for a loft conversion?

Usually, if the work involves cutting into a party wall, for example to take the bearing of a steel beam. That is section 2 work, so you must serve notice at least two months before starting and get written consent or an award.

How much notice do I have to give my neighbour?

At least two months for work to an existing party wall or structure, and at least one month for a new wall at the boundary or for excavation within 3 or 6 metres of their building. A notice is only valid for a year.

What happens if my neighbour does not reply?

They should reply in writing within 14 days. You cannot treat silence as consent: for party wall and excavation work, no reply means a dispute is deemed to have arisen, and surveyors are appointed to agree an award.

Who pays for the party wall surveyor?

Usually the building owner pays all costs of the award, including the neighbour's surveyor, where the work is solely for the building owner's benefit. The surveyors can split costs where work is needed because of defects or disrepair.

Can my neighbour stop the work?

No. A neighbour cannot stop you exercising rights given by the Act, but they can influence how and when the work is done through the notice and award process, and they are entitled to compensation for any damage.

Does the Party Wall Act cover garden fences?

Not wooden fences or hedges. A garden wall that stands on the land of both owners counts as a party wall under GOV.UK's description and is covered.

To price the work itself, see building works in London, or send photos, drawings and your postcode on WhatsApp or call +44 7304 330614.