Party walls in semi-detached and terraced houses

In a semi-detached or terraced house you share at least one wall with next door, and often a chimney stack, a roof line and foundations too. Most home improvements touch at least one of them.

What you share

  • The party wall itself, usually from below ground to the roof. In some older houses it is thinner in the loft, or missing there altogether: see no party wall in the loft.
  • Chimney breasts and stacks built against or into the party wall, often with flues from both houses side by side.
  • Foundations under the party wall, carrying both houses.
  • Garden walls on the boundary, which may be party fence walls.

Work that usually needs notice

Work Why
Loft conversion Beams bear on the party wall, which may also be raised for a dormer or gable
Chimney breast removal The breast is part of the party wall
Steel beam for a knock-through Its end usually sits in the party wall
Rear extension A new wall at the boundary, and foundations near next door
Damp proofing the party wall Cutting in a damp proof course is work to the wall

Work that usually does not

Replastering your own side, rewiring with shallow chases, fitting kitchen units and shelves, or replacing windows away from the party wall.

In a terrace, think both ways

A mid-terrace house has two party walls. A loft conversion often affects both, so both neighbours need notice.

Common questions

My house is attached to next door only by the garage. Does that count?

If the garage wall is shared, it is a party wall, and work to it is covered in the same way.

Where this comes from in the Act

Links go to the official text of the Party Wall etc. Act 1996 on legislation.gov.uk.

Need a party wall surveyor?

Ivan Larkin acts for building owners, for neighbours, and as one agreed surveyor for both. Fixed fees, agreed in writing before anything starts.

Call 07477 207993Send an enquiry