The next ‘must have’ and one I nearly forgot is a surveyors inspection. Solicitors should inform you of this upon purchase. My cottage appeared to be the accepted 1 metre from the boundary. Not apparently so, it is 800mm from the boundary at one end and 900mm at the other end. This can cause hell with council and plans to make any additions. In my case, the wall in the extension closest to this boundary was unable to have windows, or openings of any kind, and has to be constructed of fire resistant materials.