Hi
@Michael James thomas good question. When I attended my STROMA assessment it was around five hours. We went through paperwork including level 3 exams, insurance, third party contract, GS85, EAWR, technical questions such as talking about R1/R2 adiabatic, types of system and when they are recommended for inspection time wise etc. complaint procedure all in all quite a thorough process. Then of course off to site to inspect installation and do Ze (with safe isolation!) and Zs and RCD testing. I definitely came away with the sense that if you were not an electrician it would have been clear as the questions (about fifty) on a science/techy level and practicals would soon show if you knew your onions. As
@Wilko suggests is he really STROMA registered, I find it hard to beleive he could have got through with such a paucity of knowledge they are pretty thorough imo.