If you live in a semi-detached or terraced house in Cornwall, or your extension will be built close to a neighbour's property, there's a good chance the Party Wall etc. Act 1996 will apply to your project. It's a separate requirement from planning permission and Building Regulations, and it's easy to overlook until late in the process. This guide explains in plain terms what the Party Wall Act covers, when you need to serve notice and how the process typically works, so you can plan for it from the start.
What is the Party Wall Act?
The Party Wall etc. Act 1996 applies across England and Wales, including Cornwall. It sets out a framework for carrying out certain types of building work that affect a shared wall, a boundary wall or the foundations of a neighbouring building. The aim is to protect both sides: you can carry out the work you're entitled to do, and your neighbour has a fair process for raising concerns and making sure any damage is put right.
The Act is a civil matter between neighbours. Cornwall Council doesn't enforce it, and having planning permission or Building Regulations approval doesn't mean you've complied with it.
Which works are covered?
The Act typically applies to three broad types of work:
Work to an existing party wall or party structure. This includes cutting into a shared wall to insert a steel beam, raising the height of a party wall, removing chimney breasts attached to it, or underpinning it. It's common in loft conversions and when removing a load-bearing wall in a terraced or semi-detached house.
Building a new wall on or at the boundary line, known as the line of junction, such as the side wall of an extension built right up to the boundary.
Excavating near a neighbouring building. This usually applies where you dig within three metres of a neighbour's building and deeper than its foundations, or within six metres where the excavation would cut a 45-degree line drawn down from the bottom of their foundations.
Minor work such as fixing shelves, replacing sockets or replastering doesn't usually need notice. If you're unsure, it's worth getting advice before work begins.
Serving party wall notice
If your work is covered, you need to give your neighbour written notice before starting. The person carrying out the work is known as the building owner, and the neighbour as the adjoining owner. Notice periods are set out in the Act:
At least two months' notice for work to a party wall or party structure.
At least one month's notice for a new wall on the line of junction or for excavation near a neighbouring building.
A notice should include your name and address, the address of the property, a description of the work and the proposed start date. Drawings are usually included for excavation work. You need to serve notice on every affected owner, which may include a landlord or other owner as well as the occupier. The government publishes an explanatory booklet on the Act, which is a useful reference.
It's always worth talking to your neighbours before the formal notice arrives. Explaining your plans in person often makes the process smoother.
How your neighbour can respond
Once notice is served, your neighbour can consent to the work, or dissent. If they don't respond within 14 days, a dispute is treated as having arisen. Consent is often given where the work is straightforward and relationships are good.
If there's a dispute, it's resolved through party wall surveyors. The two owners can appoint one surveyor together, called an agreed surveyor, or each appoint their own. The surveyors prepare a document known as a party wall award, which typically sets out what work will be done, how and when it will be carried out, and usually records the condition of the neighbouring property beforehand. Surveyors' fees are normally paid by the building owner.
Schedule of condition
Even when a neighbour consents, a record of the condition of their property before work begins is sensible. A schedule of condition, with written notes and photographs, makes it much easier to deal fairly with any claim of damage later. It protects you as much as your neighbour.
How the Act fits with planning and Building Regulations
Planning permission, Building Regulations approval and party wall procedures are separate, and a typical extension or loft conversion may need all three:
Planning deals with whether the development is acceptable, and Cornwall Council decides applications. Some extensions fall under permitted development instead. See our guide to planning permission in Cornwall.
Building Regulations cover how the work is built, including structure, fire safety and energy efficiency. Our guide to Building Regulations in Cornwall explains the process.
Party wall procedures deal with your rights and responsibilities towards neighbouring property.
Because notice periods can be one or two months, and a dispute can add more time, it's sensible to start the party wall process once your design and structural details are settled, rather than waiting until just before work starts.
Party walls in older Cornish homes
Many terraces and semi-detached homes in Cornwall have solid stone or rubble party walls, sometimes with shared chimneys and timbers built into the wall. These walls can behave differently from modern masonry, so a structural engineer's input matters when cutting in steels or forming new openings. Our pages on home extensions and property renovations explain how we approach these projects, and our article on renovating an old Cornish cottage covers older buildings more widely.
Party Wall Act FAQs
Can my neighbour stop my extension under the Party Wall Act?
The Act doesn't generally give neighbours the power to stop work you're otherwise entitled to do. It provides a process to agree how the work is carried out and to protect their property. Planning decisions are a separate matter for Cornwall Council.
Do I need a party wall surveyor?
Not always. If your neighbour consents in writing, you may not need one, although a schedule of condition is still sensible. Surveyors are needed when there's a dispute.
What if work starts without notice?
Starting notifiable work without serving notice can lead to delays, disputes and potential legal action. It's best to serve notice well ahead of your planned start date.
Talk to us about your project
If you're planning an extension, loft conversion or structural alterations anywhere in Cornwall, we can help you plan the build and work alongside your designer, engineer and party wall surveyor. Call us on 01208 816991 or contact us to talk through your plans.
