A party wall is a wall (or sometimes another structural element) that sits on the boundary line between two neighbouring properties and is used by both owners. It often forms part of the structure that separates the buildings and can provide support to one or both properties.
In practice, if two properties share a wall as part of their construction—or a wall straddles the boundary—the Party Wall etc. Act 1996 may apply when work is planned.
Common examples of party walls
Party walls are most commonly found in:
- Terraced houses: the dividing wall between adjoining homes
- Semi-detached houses: the wall separating the two halves of the pair
- Converted or subdivided buildings: where structural walls serve more than one unit
- Boundary walls (in some cases): a masonry wall that sits astride the boundary and divides gardens or yards
Shared features that can be included
It’s not just the main wall that matters. Certain shared or attached structural features may also be relevant, such as:
- Chimney breasts or chimney stacks connected to a shared wall
- Structural piers or buttresses built into or supporting a shared wall
- Retaining or support walls where they form part of the boundary arrangement (depending on how they’re built and positioned)
Party structures in flats and maisonettes
The Party Wall etc. Act 1996 also covers “party structures”, which are shared structural parts within buildings split into separate units. This often includes:
- Floors and ceilings between flats
- Other shared structural separations where one unit sits above or next to another
So, even if you don’t have a “shared wall” in the typical house sense, the Act can still be relevant in apartment buildings.
Why correctly identifying a party wall matters
Knowing whether something is a party wall (or party structure) is important because it determines whether the Act’s procedures apply. If your work affects one of these shared elements, you may need to:
- Serve formal notice on the adjoining owner(s)
- Allow time for consent or dissent
- Potentially appoint party wall surveyor(s) and agree a Party Wall Award before starting
Implications for building work
Work that often triggers the Act includes:
- Cutting into the wall (e.g., for steel beams)
- Removing or altering chimney breasts
- Underpinning, raising, thickening, or rebuilding sections of the wall
- Structural works that affect floors/ceilings between flats
Getting it wrong can lead to disputes, delays, and sometimes legal action—often at the worst possible time (mid-project).
Want help confirming if your wall is a party wall?
If you’re unsure whether a wall or structure is covered, email mail@howorth.uk with your address, a short description of the work, and any plans/drawings you have. We can help you identify what’s covered and what steps you need to take next.