Can my neighbour build a roof extension without planning permission?
In most cases, if the property is a single dwellinghouse (and not flats) and not in a conservation area, then your neighbour may erect a roof extension to the rear of the property without planning permission. However, there are a number of restrictions and limitations, and although some of the size limitations are explained below, given the complexity of the legislation and the fact that some developments have conditions which remove permitted development rights, you can seek confirmation by contacting Planning Services or visiting the Planning Portal website. The total volume of the extension(s) to the roof must not exceed 40 cubic metres, in the case of a terraced house or, 50 cubic metres in any other case. The roof extension must not front a highway and must not exceed the highest part of the existing roof. Internal loft conversions that do not extend beyond the existing roof may not require planning permission. However, the insertion of a roof-light in a conservation area may requ
