Looking for suggestions for a lightweight roof for existing sunroom. I have been suggested polycarbonate.It has an existing perspex [?] like roof.Putting a slate roof with velux is not an option as existing side windows [pvc ] are already in place. Looking for something that prevents sunroom getting too hot in Summer and loosing heat in winter.Sunroom will now serve function of dining room. Saw on 1 website on polycarbonate whereby green, blue, silver, gold filters could be used.Can one recommend company in the mid west area [Clare]