If a previous certificate exists, consumer unit upgrades on a period flat usually starts by checking whether it still reflects reality. We handle the letter chain if needed. The point of a proper test is that the result is repeatable by anyone else with the same instrument. It is the difference between a fixed price and an estimate.
The order of work matters: isolate, test, explain, then price. Skipping the middle two is how people end up paying twice. Nothing about it is unusual for property of that age. Consumer unit upgrades on a period flat is one of the more commonly misquoted jobs, largely because nobody tests before pricing it.



