Expert advice: what to look for in a rooflight

Considering rooflights for your next project? Read this expert advice on glass specification.

By Rebecca Foster | 13 August 2020

Consider the type of glass, framing options, size and specialised features of different rooflights to suit your design.

rooflight open plan - expert advice on rooflight glass specification - home improvements -

Image: De Rosee Sa

From fixed and opening products suitable for pitched and flat roofs to traditional lanterns, the term rooflight covers an array of overhead solutions. The Grand Designs magazine team spoke to Rebecca Clayton from IQ Glass, who has shared her expert advice on glass specification.

Glazed to perfection

rooflight living room - expert top tips for incorporating rooflights into your design - home improvements -

Image: Velux 

All rooflights to internal spaces should be double glazed as standard, but triple glazing is also available if higher thermal performance is required. A solar control coating will reduce how much solar radiation can come through the unit and reduce overheating that could occur internally.


Self-cleaning coatings can be useful to reduce manual cleaning. These applications are only effective on roof glazing with a pitch of more than 20°. Roof windows with falls lower than this don’t have enough of an angle for dirt to be washed away by rainwater, however, so this type of coating wouldn’t be effective.