What Is a Party Wall?

A party wall is a wall that stands astride the boundary between two properties and is
shared by the owners on either side of it. The everyday example is the wall between two
terraced or semi-detached houses, but the legal definition is wider than most people expect:
it also covers a wall that sits wholly on one owner’s land but is built up against by the
neighbour, a garden wall built astride the boundary, and the floors and ceilings between
flats. Structures that separate buildings are covered too, which is why the rules bite on
loft conversions and basement digs as often as they do on extensions.

The legal definition under the Party Wall etc. Act 1996

The Party Wall etc. Act 1996 is the statute that governs all of this in England and Wales.
It does three things. It gives a building owner rights to carry out certain works that would
otherwise be a trespass or a nuisance. It gives the adjoining owner the right to be told in
advance, to have the existing condition of their property recorded, and to be put back right
if the work causes damage. And it provides a surveyor-led dispute procedure so that neither
side has to go to court to resolve a disagreement.

The Act recognises two distinct things. A party wall proper is one that is
shared, either because it stands on the boundary or because both owners have built into it. A
party fence wall is a free-standing garden or boundary wall that straddles the
line; a fence panel or a wall standing entirely on one side is not covered. A
party structure is the wider category that takes in floors, ceilings and
partitions separating parts of a building in different ownership.

What “party wall agreement” actually means

People usually say “party wall agreement” when they mean one of two things. Either the
neighbour has signed a consent letter, in which case no surveyor is needed and the work can
proceed, or the neighbour has dissented and a party wall award has been drawn
up by surveyors. The award is the formal document; it is what most solicitors will ask to see
when the property is later sold. Both routes begin with a notice.

Work that requires a party wall notice

• Section 1 — building a new wall on or at the line of junction where nothing
  currently stands.
• Section 2 — work directly to an existing party wall: cutting in for beams,
  inserting a damp-proof course, underpinning, raising it for a loft conversion, or taking it
  down and rebuilding.
• Section 6 — excavating within three metres of a neighbouring structure and
  going deeper than its foundations, or within six metres where the excavation falls below a line
  drawn at 45 degrees from the base of their foundations.

Notice periods differ: two months for section 2 work, one month for section 1 and section 6.
The notice must be served before work starts, and it lapses if work has not begun within twelve
months.

Your neighbour started work without a party wall agreement

This is the single most common reason people ring us. If notifiable work has already begun
without a notice, the building owner has no statutory protection and the adjoining owner can in
principle seek an injunction to stop the work. In practice injunctions are expensive and the
courts expect you to have tried to resolve matters first. The usual and far cheaper route is to
write to the building owner setting out that the work is notifiable, ask them to serve a notice
retrospectively and appoint a surveyor, and get a schedule of condition recorded on your side
straight away so there is an agreed record of what the property looked like before the work
went further. If damage has already occurred, photograph and date everything.

What a party wall surveyor does

The surveyor’s duty under the Act is to the Act itself, not to whoever appointed them. Both
owners can appoint a single “agreed surveyor”, which is quicker and cheaper, or each can appoint
their own. The surveyor records the condition of the adjoining property, settles what work is
permitted and how it must be carried out, sets out working hours and access, and produces the
award. Ordinarily the building owner — the one doing the work — pays the reasonable surveying
costs on both sides.

Party wall advice in Canterbury and Kent

We act as agreed surveyor and as an appointed surveyor for either side across Canterbury,
Whitstable, Herne Bay, Faversham, Ashford, Maidstone and the Thanet towns. Canterbury’s older
terraces and the city-centre conservation areas throw up more than their share of shared
chimney stacks, mixed-era brickwork and shallow Victorian foundations, all of which change how
a notice should be framed and how carefully the schedule of condition needs to be written.

Frequently asked questions

Is a party wall the same as a boundary?

No. The boundary is a legal line; a party wall is a physical structure. A party wall usually sits on the boundary, but a wall can stand entirely within one owner’s land and still be a party wall if the neighbour has built into it.

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

Almost always yes, because steel beams are normally cut into the shared wall, which is section 2 work and needs two months’ notice.

What happens if my neighbour ignores the notice?

Silence is treated as dissent after fourteen days. A dispute is deemed to have arisen and surveyors are appointed; the work is not blocked, it simply proceeds under an award.

How long is a party wall award valid?

The award itself does not expire, but the notice underpinning it lapses if the work has not started within twelve months of service.