You will receive fitting instructions with every product you buy from FAKRO. Here we will be talking about a centre pivot roof window and using an example question:
Customer: 'I bought a 78 x 98 centre pivot roof window from you. In the fitting instructions there is a formula for working out the roof aperture to fit the window in to. in my instruction it is S + (2 divided by 5) for the width and H + (2 divided by 4) for height. For my window I work that out as width 78.4cm and height 98.5cm, which does not seem right?'
To solve this, the answer for the fitting is 10mm all the way around. This should make your window easier to fit.