Some legitimate whingeing at gas-news.co.uk. Easy to blame corgi but it's the ODPM which is requiring the notifications. Many at least of these types of works have "always" needed notification to Bldg Control, but nobody bothers.
Corgi are as ever over-keen to get people to sign up and pay, even though last time I looked their scheme wasn't approved yet.
Major point corgi would cover up, is that notification is only required for new installations, so not eg replacing a bathroom.
BC depts seem to be least bothered, with no extra money to monitor, etc. They certainly don't seem to care much about Unvented cyls.
People say ah but, and point to the Home Info Pack and its need for records of pukka chappies, but if and when that'll matter, nobody knows.