I have a flat roof extension 3x9m on the back of the house which isn't insulated (built 50 years ago). The flat roof is c10 years old and in excellent repair. The room below the roof is very cold in winter due to no insulation. We had a quote today for 100mm kingspan insulation to be put on top (warm roof insulation) and the GRP fibreglass roof in top. £7k plus VAT. While I'm sure this will make the room warmer the payback on the cost of doing this must be many years indeed and it's difficult to justify such a lot of money when the roof we have is watertight etc. 2 questions: 1. Does the quote sound about the right value? 2. Is their a cheaper option we should consider? We have wondered about insulating the room ceiling by dropping it down and putting insulation behind it, but I know this won't be as warm. But it'll surely be a lot cheaper? Thank you
