Thanks Surrey.
I wonder what the installer checks during inspection though & what the MCS regulations ask for. Wonder if there is a standard saying what to expect from each roof type.
Also in a roofer's experience is my style of roof standard or are the timbers smaller than usual/liked...
I am neither a roofer nor an engineer, so plz correct me if my figures are wrong!
I rang building control on the advice of my Tesco PV solar quote. Building control explained that solar fit was a strange one as the work was self certified but that the installers may not be qualified...