To insert translucent windows in a back of a house made up of flats planning permission is necessary. However no planning permission is necessary if this house is considered as being a single dwellinghouse. In this case if permission is not granted because for example there have never been any translucent windows at this place and it will affect the privacy of the neighbours, will it be possible to make an application to have this house considered as a single dwellinghouse only to have finally these windows inserted. And what will happen if the owner of this house changes again the use of this property and this property is not anymore considered as a single dwellinghouse will have these windows to be removed ?