A wall is a ‘party wall’ if it stands astride the boundary of land belonging to two (or more) different owners. The Party Wall Act 1996 provides a building owner, who wishes to carry out various sorts of work to an existing party wall, with additional rights going beyond ordinary common law rights. Section 2 of the Act lists what work can be done. The most commonly used rights are:

  • To cut into a wall to take the bearing of a beam (for example for a loft conversion), or to insert a damp-proof course all the way through the wall

  • To raise the height of the wall and/or increase the thickness of the party wall and, if necessary, cut off any projections which prevent you from doing so

  • To demolish and rebuild the party wall

  • To underpin the whole thickness of a party wall

  • To protect two adjoining walls by putting a flashing from the higher over the lower, even where this requires cutting into an adjoining owner’s independent building.


If work falls on to a party wall, it is a requirement to have a ‘Party Wall Agreement.’ You must notify all neighbours in writing at least two months before the planned start date for work to the party wall. The notice is only valid for a year, so shouldn’t be served too long before you wish to start.