Hi all! We pulled down a few ceilings today and this gave me a good look at the roof in the back room of our vicorian rear addition. This part of the house has a low, sloped roof with no loft space. This is what it looks like: Now, there was no roof insulation there before, and given that it also has 3 external walls, it has always been pretty chilly. I was wondering if it's possible to add insulation without decreasing the height of the room substantially. The spot where the ceiling is horizontal should be easy enough - we can add rockwool insulation above the ceiling plasterboard. For the sloped part of the ceiling, I was wondering if it's possible to: - add 50mm rigid insulation board to the 10cm rafters, leaving a 50mm ventilation gap - attach a 27mm insulated plasterboard to the rafters I know this doesn't give a great deal of insulation, but I'm operating on the principle of something is better than nothing. We really don't want to sacrifice height - it's a very pokey room already. Does this make sense, and would this provide enough insulation under the rafters to avoid cold bridging and condensation issues? Also, does this leave enough ventilation under the roof? Thanks all - I would appreciate any insight into this, and maybe experiences from someone who has a similar room.