What is a Party Wall Notice

A Party Wall Notice is the formal written notification a Building Owner serves on their neighbours before carrying out certain works to a shared wall, a boundary wall or an excavation close to a neighbouring building. If you are planning an extension, a loft conversion or a basement, there is a good chance you will need to serve one, and getting it right at the start makes the rest of the process far smoother.

The short answer

A Party Wall Notice is a formal written notice that a Building Owner serves on an Adjoining Owner before carrying out works covered by the Party Wall etc. Act 1996. There are three main types: a Line of Junction Notice under Section 1 for a new wall on the boundary, a Party Structure Notice under Section 3 for works to an existing party wall, and a Notice of Adjacent Excavation under Section 6 for excavations near a neighbour's foundations.

What is a Party Wall Notice?

A Party Wall Notice is the document that starts the procedure under the Party Wall etc. Act 1996. It tells your neighbour, known under the Act as the Adjoining Owner, what you propose to do, where and when, so that they have the opportunity to respond before any notifiable work begins.

The Act applies in England and Wales. It does not give your neighbour the power to stop lawful building works, but it does stipulate that notice is served and that the correct procedure is followed.

What are the three types of Party Wall Notice?

The three main notices are the Line of Junction Notice (Section 1), the Party Structure Notice (Section 3) and the Notice of Adjacent Excavation (Section 6). Which one you need depends on the work, and many projects need more than one.

Line of Junction Notice (Section 1)

A Line of Junction Notice is served where you intend to build a new wall on or astride the boundary line between your property and your neighbour's, known as the line of junction. A typical example is the flank wall of a new side or rear extension built up to the boundary.

The Act stipulates at least one month's notice before the work starts. If you wish to build the wall astride the boundary, you need your neighbour's consent; without it, the wall must be built wholly on your own land.

Party Structure Notice (Section 3)

A Party Structure Notice is served for works to an existing party wall or party structure. Section 2 of the Act sets out the rights a Building Owner has, and the notice for those works is served under Section 3. Common examples include cutting into a party wall to insert steel beams, raising the height of the wall, underpinning it, and removing chimney breasts.

The Act stipulates at least two months' notice. The notice must state your name and address, the nature and particulars of the proposed work, including details of any special foundations, and the date on which the work will begin.

Notice of Adjacent Excavation (Section 6)

A Notice of Adjacent Excavation is served where you intend to excavate within 3 metres of a neighbouring building or structure and to a lower depth than the bottom of its foundations. It is also needed within 6 metres where the excavation would cut a line drawn downwards at 45 degrees from the bottom of the neighbour's foundations.

The Act stipulates at least one month's notice. The notice must state whether you propose to underpin or otherwise strengthen the neighbour's foundations, and it must be accompanied by plans and sections showing the site and depth of the excavation. Rear extensions and basements are the most common triggers.

How much notice do I need to give?

You must give one month's notice for a Line of Junction Notice or a Notice of Adjacent Excavation, and two months' notice for a Party Structure Notice. These are minimums, so serve notice well before your builder is due on site.

Notices do not last indefinitely. If the works have not begun within 12 months of the notice being served, the notice lapses and a new one would need to be served.

What happens after a Party Wall Notice is served?

Once served, your neighbour has 14 days to respond. They can consent to the works, or dissent, in which case a dispute arises under the Act and surveyors are appointed. If they do not respond at all within 14 days, a dispute is deemed to have arisen.

The word dispute can sound alarming, but it is simply the term the Act uses to bring the surveyor process into play. We explain this in our guide to what dissent means on a Party Wall Notice. Under Section 10, the owners either concur in appointing a single Agreed Surveyor, or each appoints their own surveyor. The surveyors then prepare a Party Wall Award, which usually includes a Schedule of Condition of the neighbour's property and sets out how the works are to be carried out.

The Building Owner generally pays the reasonable costs of the process where the works are for their benefit. Our article on who pays party wall surveyor fees explains this in more detail.

Is a Party Wall Notice the same as planning permission?

No. Planning permission, permitted development and Building Regulations are entirely separate from the Party Wall etc. Act 1996. Having planning approval, or building under permitted development rights, does not remove the need to serve a Party Wall Notice where the works are notifiable.

Frequently asked questions

Can I serve a Party Wall Notice myself?

Yes. The Act does not stipulate that a surveyor must serve notice, and a Building Owner can serve it themselves. In practice, errors in the content or service of a notice are common, which is why many owners ask a surveyor to prepare and serve it. Our guide to what makes a Party Wall Notice valid covers the details.

Do I need to serve notice on every neighbour?

You need to serve notice on every Adjoining Owner affected by the works. That can include the owners on both sides, the owners of neighbouring flats, and in some cases more than one owner of the same property, such as a freeholder and a long leaseholder.

Can one project need more than one type of notice?

Yes, and it is common. A rear extension may need a Notice of Adjacent Excavation for the foundations, a Line of Junction Notice for a new boundary wall, and a Party Structure Notice if a beam is cut into the party wall.

Speak to a Chartered party wall surveyor in North London

Hudson Party Wall Surveyors is a Chartered, RICS-regulated practice based in North Finchley, acting for Building Owners and Adjoining Owners across North London. We prepare and serve Party Wall Notices as a matter of routine and can advise on exactly what your works involve. For advice on your project, call Simon on 020 3488 7747 or email simon@hudsonpartywallsurveyors.co.uk.