Answer: The notice you have been sent is a requirement of the Party Wall Act, it is not anything to do with planning control, which your neighbour may or may not need to build his extension legally. The Party Wall Act is there to agree how it is to be built in relation to your property and provide a degree of protection to you should your property sustain damage because of it. If your neighbour has or does not need planning consent, the Party Wall Act can not prevent him proceding. Please contact Stephen Cornish at our office, who is a Fellow of the Faculty of Party Wall Surveyors, as well as a Chartered Surveyor.