For my extension build the electrical supply meter was moved to a box outside. Rather than moving the old consumer unit I opted to have a new one fitted. The electrician who came to look at the job told me I could provide the cu. When I rang him to ask which one to buy he said it now has to have surge protection. If that’s the case why are outlets still selling the ones without. Is the electrician correct that it MUST have surge protection fitted to meet the latest regs? Thank you.