Choose an opening rooflight where the room needs ventilation — kitchens, bathrooms, bedrooms and any south-facing room that could overheat. A fixed rooflight is simpler, cheaper and quieter where the room already ventilates well through doors and windows.
Why ventilate through the roof?
Warm air rises, so an opening at the highest point clears heat, steam and smells faster than a window at head height.
Can an opening rooflight be purge ventilation?
Yes, if its opening area and angle meet Approved Document F. Openings of 30° or more need at least 1/20 of the floor area; 15–30° needs 1/10. Check the manufacturer's figure.
What does a rain sensor do?
It detects water and closes the lid automatically. Fit one on any opening rooflight over a living space.
How much more does an opening unit cost?
Expect to pay roughly £960–£1,800 more than a similar-sized fixed unit, plus the electrical supply.
Can I mix fixed and opening units?
Yes — a large fixed unit for light with a smaller opening unit for air is a common and cost-effective layout.
This guide gives general information, not legal or structural advice. Rules change and every property is different — check with your council or building control for your address. We review our guides regularly; the date above shows the last review.
Sources
Find this useful? Add SkylightCompany.uk as a preferred source on Google.
