In these days of shaper belt tightening, then many families are opting to extend or alter their existing property rather than sell up and try to find a suitably spacious house to buy. There were some very large family developments built around the late 1990s into 2000s, but with there was difficulty in obtaining sufficient plots to continue in this vein. It is only in recent years that a loosening of the green belt land rules and general planning by local planning authorities, has allowed the resumption of larger executive home building. However there are some very important rules surrounding the replacement of certain features in a home. You can’t just rip out the boiler fed heating system and replace with a wood burning stove for example, Planning permission is not generally needed for replacement of an exiting system if using like for like but if the new scheme requires an outside flue, it is essential to check it will fit in the permitted development criteria. i.e. Flues must not exceed the highest section of any part of the roof by a metre or more. If the building is listed, or in a designated area (with or without other pwermitted development rights), it is essential to check with the local authority before any work is undertaken or purchase made, and most definitely before any flue is fitted.