14-12-2019, 12:12 PM
Chris, Just an idea. The best natural insulator is air. Putting a second clear skin with an air gap to create a dead air space but let the light through may do the job. Back on our boat I did this to the windows in our deck-house using a heat shrink film, bought cheaply off ebay, stuck with double sided tape to the inner window surrounds to give an approx 2 inch air gap. Condensation which we had in buckets before ceased and the heat input fell and comfort level rose to an amazing degree. Also easy to remove and replace as required seasonally. You would of course need to seal the edges of the existing roof but expanding foam would make an easy job of this.