You've needed either a FENSA certificate or building regs since 2002 I think. If the firm haven't supplied the certificate you'll need the council's building inspector to come out and check them for the appropriate markings on the glass and thermal efficiency.
As you say, call the firm first and go from there.
You've needed either a FENSA certificate or building regs since 2002 I think. If the firm haven't supplied the certificate you'll need the council's building inspector to come out and check them for the appropriate markings on the glass and thermal efficiency.
As you say, call the firm first and go from there.