Hmm. At what point are you paying to heat the outside world? Insulation as a one off cost is the no-brainer choice because it should be very cheap and just be a one off to fit.
Adding tens of thousands to costs makes me think someone is getting taken for a ride
@sinabhfuil
I know Irish companies like to mark up things that cost pennies like ibuprofen, and other commodity chemicals, I hadn't realised they were doing it with insulation too!
This rockwool https://www.wickes.co.uk/Rockwool-Thermal-Insulation-Roll---100-200mm/p/148843 is wildly pricey in my opinion and you can get equivalent cheaper
https://www.wickes.co.uk/Knauf-Insulation-Super-Top-Up-200mm-Loft-Roll---5-61m%C2%B2/p/109451
So that will do 25 sq m for £355 https://www.homebuilding.co.uk/advice/insulating-a-roof
If you're paying more than 1000-1500 (including boarding!) Then I'd think you were being ripped off.