Flat roof windows

The daylight size is what you see from inside. The roof opening is the opening in your roof. With a straight curb (/00), they are the same size. With a sloped curb (/20 or /30), the roof opening is 20 or 30 cm larger.

Example: sloped curb /20, daylight size 1000 × 1000 mm → roof opening 1200 × 1200 mm.

Subtract 160 mm from the external size. That is the flange: 80 mm on each side. An external size of 1160 × 1160 mm gives a daylight size of 1000 × 1000 mm.

Measure the clear opening at the top of your curb: width × length. That is your daylight size. This is the size you order, for a skylight and for a flat roof window.

First choose your daylight size. Then make the roof opening to size. With a straight curb, it equals the daylight size; with a sloped curb, it is larger.

No problem. With a renovation frame, you can install a new Skylux skylight or flat roof window on your existing curb. No demolition work required.