The short answer
The Party Wall etc. Act 1996 can apply to roof work when the job cuts into, raises, rebuilds or otherwise affects a wall, parapet or stack that stands between you and next door. Repairing slates on your own side usually does not trigger it. Because the duty to give notice falls on the owner, not the roofer, check before work begins and keep any agreement in writing.
Why roofs in terraces and semis are different
On a detached house every wall and every slope belongs to you. In a terrace or a pair of semis, the roofs run on from one house to the next, and what separates them is a wall. That wall is often built up through the roof space and finishes above the slates as a parapet or a stack of chimneys. Because it belongs to both properties, work on it is shared business.
Bath is full of this pattern. Georgian and Victorian terraces, mansard roofs behind parapets, valley gutters running along the line between two houses and chimney stacks serving fireplaces on both sides are all ordinary here. In these houses a gutter that sits on top of the dividing wall, or a flashing chased into it, is no longer purely your own roof.
The Act itself is the Party Wall etc. Act 1996, and the government publishes a plain explanatory booklet for owners on gov.uk. We are roofers, not lawyers, and what follows is general information. Check your own position before work starts.
Roof jobs that may bring the Act in
The question for each job is whether it does something to the shared structure. Jobs that commonly raise it include:
- Raising or rebuilding a parapet that sits on a shared wall.
- Cutting into the shared wall to take a new beam, seat a new valley or fit a new flashing. Cutting into a party structure is one of the works the Act lists.
- Rebuilding or reducing a chimney stack that stands on the dividing wall.
- Replacing a shared box gutter or lead valley that runs along the boundary and discharges across both roofs.
- Breaking into the wall for a loft conversion or a dormer that sits against the boundary.
Jobs that usually do not raise it are plain repairs on your own slope: replacing slipped slates, clearing gutters, refixing ridge tiles and relaying a covering without touching the dividing wall. Even then, a new flashing that runs against the shared stack deserves a second look. If you are unsure, stop and ask before the scaffold goes up.
Flashing means the lead strip that seals the junction between slope and wall or chimney. It is a typical spot where a repair crosses from your roof into shared structure.
How notice works and who gives it
Where the Act applies, the person doing the work, known as the building owner, must serve written notice on the adjoining owner before starting. That is you, not your roofer. The notice describes what is proposed. The neighbour can consent, and if they do not, the Act sets out a way of settling matters through surveyors, who often record the condition of the neighbour's side beforehand. That schedule of condition is not required by the Act, but the government booklet advises one as a precaution.
Doing this properly protects both sides. A neighbour who has been told what is happening, and has seen the plan, is far less likely to complain about dust, noise or access across their roof. A record of the wall's condition also protects you if a crack appears later and someone suggests your work caused it.
For work to an existing party wall, the booklet says notice must be served at least two months before the planned start. If the neighbour does not reply within 14 days, a dispute is treated as having arisen and the surveyor route follows. Fees are not fixed, so a party wall surveyor can tell you the cost for your job. Neighbours who simply agree to the work in writing can save everyone time, but you should keep that agreement.
What we do on a shared roof
At the free survey we look for exactly these points: where the parapet sits, what the chimney stands on, where the lead runs and whether any part of the plan reaches beyond your own slope. We photograph the roof as it is and explain what we find in ordinary language.
If the repair stays on your side, we tell you that and price it. If it touches shared structure, we tell you that before the fixed price is written, so notice can be served first and the programme set around it. Where listed building consent or conservation area controls also apply, we explain that side as well, and our page on conservation area roof rules sets out how those work.
A shared valley or parapet is put back as it was built, with matching lead and stone laid to the existing detail. Doing that well matters more on a shared wall, because a leak in your gutter becomes damp in your neighbour's bedroom.
Practical steps before the work
A short checklist keeps shared-roof jobs calm.
- Tell your neighbour early, in person if you can, and show them the survey photographs.
- Ask the roofer to identify every part of the job that touches the dividing wall, parapet or stack.
- If any does, take advice on notice before the start date is fixed.
- Agree access in writing, including scaffold and boards that need to stand on or overhang their property.
- Keep a copy of every notice, reply and agreement with your house papers.
Scaffold is its own question when it sits on a street, and the scaffold licence page covers it. For a wider view of how the different kinds of roof work fit together, see roofing services explained. You can also start with our main page or call 01225 285181.
