On the older rows a dormer can be awkward to fit around the roof pitch and the chimneys, and roof windows do much of the same job at lower cost. Two roof windows set beside each other on a rear slope can give an attic bedroom as much daylight as a small dormer would, without building out. We lay out the pair so the rafters between them stay intact and the finish inside is neat.
Flats and maisonettes
Shop-top flats raise a different question. A flat is treated differently from a house when it comes to planning, so a roof window in a flat needs checking with the council and the agreement of the freeholder or managing agent. South Gloucestershire Council deals with planning here. Our planning guide explains how to find out where you stand, and it is worth settling before a design is drawn. If the lease controls the roof, speak to whoever owns it first.
Where a flat's roof can be altered, the most useful addition is often a sun tunnel or a small roof window over a bathroom or landing. Both bring daylight to rooms that have no window at all, which is the usual story for a hall or an inner bathroom in a narrow building. A sun tunnel needs a straight run between the roof and the ceiling, so we check the space above the room before suggesting one. A roof window over a bathroom that opens at the top gives steam somewhere to go, and a vent bar along the frame lets a little air through overnight.
Another feature of this part of Staple Hill is how often several houses in a row have been altered. One neighbour has a dormer, another a rear addition, a third a skylight put in years ago. When we survey, we look at what has been done next door, not to copy it but to see how the roofs on the street have been treated and what a new window will sit beside.
Making the most of a small roof
Terrace roofs in the area have no spare slope. A chimney on one side, a party wall on the other and a gutter below leave a few rafters in the middle where a window can be placed. We fit units to those gaps, usually with the slim end of the roof window range, and with careful flashing so the join with the tiles stays watertight.
Replacing an existing roof window outright counts as building work that has to be notified, and our Building Regulations guide explains the details. We make the roof weathertight each evening before we leave, and we protect floors and furniture while we work, which matters in a small house where there is no spare room to shift things into.