Hi, we are planning a single storey rear extension on our 50's house, and are struggling to settle on a roof style. The extension will come out about 4m and we have fairly low first floor windows (half into eaves), so have ruled out a standard pitched roof. We had assumed this meant a flat roof, but architectural drawing person is suggesting a concealed flat roof - half pitched half flat, with roof lights in the flat bit. Our likely builder didn't seem convinced, but he does favour straightforward over fiddly-but-looks-better given the choice! Are these really awkward to build? Better than a normal flat roof? I've been thinking about this for too long and lost all objectivity. This pic from Google gives an idea of what I mean.