I decided to just have my Pollycarbonate roof removed and a new frame built, upon which a GRP roofing system was used. Inside I had 270mm thick insulation with the UPVc cladding then installed over this. The issue with this is when (and it will happen in my case through large Hail Stones) the Pollycarbonate roof fails you’ve got a heap more issues to deal with. It’s actually still very bright as the panels reflect the light and makes it more like a room. With nice lighting, plastered walls, carpeting and new furniture the old conservatory has been transformed into almost an extension.