Please can anyone tell me if their are rules of thumb or guidelines for the number and size of velux type windows to adequately illuminate a roof space.
I am converting the roof of a barn floor size 4.5m x 8m with average ceiling height about 1.8m.
Roof faces south east on one side and north west on the other.
The intention is to provide a studio/office so the lighting level needs to be fairly good. Thanks for any advice.