Bill35

It's a pitched roof with multiple leaks and other issues and so we are looking to replace the front pitch of it on a very limited budget, the focus being on restoring it's integrity. We would rather not retrofit insulation given it's a very old house and the front roof is a dormer loft conversion, I think the only way to insulate it would be pulling plaster back and doing it from inside which we can't afford at the same time as the roof. Focusing just on the front roof, which is less than 50% of the house's total roof area, could we do this without building control and forced insulation work?

The building regs say that if more than 50% of a roof (or thermal unit) is being replaced, new insulation must be fitted in line with current standards and it requires a building control application. My q is how do they calculate the 50% figure in practice? For example, I am looking at replacing the front of my pitched roof which is smaller than the back, so would be < 50% of the total roof. If it came to it, would Building Control want to count each pitch separately, or look at the total area of the roof?