I have recently been considering extending the side of my kitchen, the current structure being a standard single storey extension at the rear of a 1920 terraced house. I wondered if it was possible to incorporate the existing brick party wall as part of the new side wall of the kitchen to maximise space, and what this would entail; what permissions are needed? Does the wall need to be strengthened if I intend to increase it’s height (by approx 1 metre)? What damp proofing will be required to bring the wall in line with current building regulations?
If the existing wall is what is referred to as a Party Fence Wall (a shared boundary wall) in the Party Wall Act then you have a right to raise it and enclose upon it with your extension (Section 2(2)(a)). Your architect will need to advise you on how the wall will have to be upgraded to meet current Building Regulations but I can tell you from experience that most people decide to re-build the wall in this situation – you also have a right to do that under Section 2(2)(l) of the Act.
You will need to serve a Party Structure Notice on your neighbour explaining what you intend to do and when work is due to commence.