Raise or rebuild a shared wall, with costs and protection agreed

Semi-detached pair with the shared party wall in teal being raised above both roofs in new brickwork while a crane lifts bricks

For homeowners in England and Wales who need to raise a party wall for a loft or extension, or knock down and rebuild a defective party wall or garden wall. Compare quotes from party wall surveyors.

Sometimes a shared wall is too low, too thin or too poor to carry what you want to build. The Act lets a building owner raise a party wall, thicken it or, if it is defective or too weak for the new work, take it down and rebuild it. That is only after notice, and the building owner must make good any damage next door. A wall might be raised for a loft, extension or new roof line, or rebuilt because it is leaning, cracked or failing. A party wall surveyor can tell which situation you are in, serve the right party structure notice at least two months before work starts, and agree with the neighbour how the cost, method and temporary protection are handled. The Act applies in England and Wales.

How a professional can help

Raising a wall for a loft or extension: Describing the new height, any extra thickness and how the raised wall is flashed and weatherproofed against the neighbour’s roof, so the notice covers everything the neighbour will see.
Checking the wall is strong enough: An old wall that is thin, poorly built or out of plumb may not carry extra load. The structural engineer assesses it, and the surveyors agree whether it can be raised or must be rebuilt.
Rebuilding a defective wall: If the wall is cracked, leaning or failing, an award can set out whether it should be repaired or rebuilt, how, and how the cost is shared between the owners.
Garden and boundary walls: A wall between gardens may be a party fence wall or sit wholly on one side. The surveyor works out which, and which notices follow, before any work is done on it.
Protecting the neighbour while it is open: While the wall is down or being raised, the award covers protection of the neighbour’s rooms from weather, dust and noise, along with working hours and clearing rubble.
Making good afterwards: Recording the neighbour’s side before and after, so plaster, decoration, flashings and gutters affected by the work are put right as the award sets out.

Is this right for you?

A loft conversion, extension or new roof line needs the shared wall to be higher or thicker than it is.
The party wall between your house and next door is leaning, cracked or open at the joints.
A garden wall shared with a neighbour is failing and needs rebuilding.
Your neighbour wants to raise the wall and you need to protect your roof and rooms.

How the project usually runs

Assess the wall: A structural engineer inspects the wall and its foundations, and advises whether it can be raised, needs strengthening or must be rebuilt, before any work begins.
Notice for raising or rebuilding: A party structure notice, served at least two months before the work starts, describes the raising, thickening or rebuilding, with drawings.
Terms agreed with next door: The neighbour can consent, or object (dissent). If they object or stay silent for 14 days, the surveyors agree an award covering method, timing, weather protection and how the cost is shared between the owners.
Record and carry out the work: The neighbour’s side is recorded first. The builder then works in stages, propping where the wall is opened or taken down and keeping the weather out of the neighbour’s roof space.
Make good and close: Flashings, plaster and finishes on the neighbour’s side are put right, and the surveyors re-inspect and close the matter.

What affects the cost

Whether the wall is being raised, thickened, repaired or taken down and rebuilt.
How defective the wall is, and how the cost is shared between owners where a defect is the reason for the work.
The length and height of the wall, and the materials used.
Whether the neighbour agrees to the work, or an award has to settle method, timing and protection.
How much making good is needed on the neighbour’s roof and rooms.

Wall safety, approvals and the Act

The Act covers raising and rebuilding party walls in England and Wales only. Scotland and Northern Ireland have different rules, though party wall surveyors work across the UK.
Raising a wall is often part of a loft, extension or roof project that needs its own Building Regulations approval, and sometimes planning permission. Both differ across England, Scotland, Wales and Northern Ireland.
A wall that is leaning, bulging or cracked can be unsafe. Have a structural engineer look at it before it is raised, loaded or taken down.
A neighbour who consents to the notice is not approving your planning application, and a planning decision does not replace the notice. Listed buildings need listed building consent as well.

Questions people ask

Can I raise a party wall without my neighbour’s permission?

You do not need their permission, but you must serve notice first. If the wall can carry the extra height, the Act gives you the right to raise it, and an objection leads to an award rather than a veto. You must protect their property and put right any damage.

Who pays if the party wall is defective?

It depends on the cause and on how each owner uses the wall. Where the work is needed because of a defect, the cost may be shared between the owners rather than falling on one. The surveyors decide the split in the award.

What is the difference between raising and rebuilding?

Raising adds height to an existing wall that is sound enough to carry it. Rebuilding means taking the wall down and building it again, which is needed if it is too weak, thin or damaged. The engineer’s assessment decides, and the notice must say which.

Is a garden wall a party wall?

Not always. A wall that stands across the boundary line between two gardens can be a party fence wall under the Act. A wall wholly on one person’s land is different, though digging next to it can still need a notice. A surveyor can tell which you have.

How tall can I make a raised party wall?

The Act does not set a height. The limit comes from what the wall can safely carry and from planning and Building Regulations rules. The engineer designs the raised wall, and the notice describes it in detail.

Available across the UK

Party wall surveyors cover the whole of the UK. The Party Wall etc. Act 1996 applies in England and Wales; Scotland and Northern Ireland have different rules, and a professional can tell you what applies to your property.