hello all , i am looking for info on installing a velux style attic window and was wondering how hard it actually is , my main concern is do i have to reinforce the rafters either side of window and how to cut slates without breaking them . roof spec = slate pitched end terraced house built 1900 ,horizontal baton between slate and felt approx 220-230 mm apart , rafter are 50x80mm (2x3inch) and sit on 80x280mm (3x11inch) beams halfway down roughly 2.2mtrs . i have seen one installation on the net where they basicly cut out a rafter and screwed in a window after a bit of jiggery pokery , is it really that simples 
