Skanx

Hi, I have put in for permitted development for an extension, read up on all the regs but got turned down as it's too long. The existing house is over 100 years with no extension built after this time. The main house is square and has a two story 6m long 3m wide room coming off back which has a courtyard to the side. I want to build over the courtyard to the side of the rear house and join onto existing annex. The extension doesn't go past the side of the main house and goes 1.4m beyond the rear wall of the house. Is the council correct in their decision or have they misconstrued my plan. The house is not covered by any local building restrictions e.g. listed or article 4.