If you have space on this outside of your property then why not look into building a Conservatory. The walls of Conservatories are made from window profile. Specialist companies have established themselves as roof only suppliers for the trade. The most common material for a Conservatory roof is Plastic followed by Aluminium, both of which can be coloured.
The rafters of a more expensive timber roof use Aluminium capping’s. These aluminium sections trap the glass unit from above. I have seen a couple of examples where a timber roof has been capped with timber – they don’t last long!
Roof glass has improved to the point where it offers: 1. Solar reflection, this reflects the suns heat away, 2. Low E coatings that bounces internal warmth back, and, 3. Easy clean finishes that break-up dirt particles which wait to be washed away by the rain. The glass still needs to be cleaned periodically.
If you have the budget and space then also consider an ‘Orangery.’ The modern take on an old design, it is mainly a brickwork construction with flat roof. The flat roof has most of its area covered by a Roof-light. Tradition has it that the windows and doors are Georgian with vertical sash sliding windows. Look through the Sunday supplements to see examples.
These walk-on roof-lights are made to measure. They can be single or double glazed. Made from toughened glass which is laminated and set in an aluminium frame.