Bubble wrap

My GH. Is a Halls cedarwood build. Purchased second hand in 1984. Replaced the roof glass with twin walled poly carbonate sheets some time back. The poly carb sheets have an alternative inside/outside presentation. Hopefully, I applied them to screen off uv rays.
Internal insulation is via small bubble plastic sheeting. This I obtained from a commercial packaging company. I generally find that, buying 'outside' the gardening market, a fairer price is available.
The roll being about 30" wide is a comfortable width to handle. Using a stapler it can soon be fixed to the inside of the glazing bars. The space now, between the inner surface of the polycarbonate roof and sides gives extra thermol protection. If an when the insulation gets dirty etc, it's no problem to remove and replace.