Is it best and cheapest to have your windows fitted by a big double glazing firm, a builder, or?

Question

some other solution? I know you can buy the windows and doors in places like Wickes, but isn't it tricky to get the measurements right? And do independent builders know how to fit them properly? The double glazing firms all seem so expensive which is why I'm looking round for alternatives.

Answer 1

whoever does it has to be FENSA registered or

apply to the local council to check whether they want a planning permission application (changes look of the house) and building regs (affects thermal performance)