Check building control regulations

I hope you're well. I applied for two certificates of regularisation for work I've done. I had called my council, Brent, before starting the work (replacing all rotten windows in 2014 and installing bifold doors in the kitchen) and they said i didn't need to apply for planning permission, but failed to mention that I needed to apply for building control, which has only come to my attention now that I'm selling my house.
The building control surveyor came on two occasions but didn't issue me the certificates due -in his view- to not meeting specs in terms of ventilation. however, for what I can see online, those specs only came into force in 2022.
I've emailed and messaged him my findings but he refuses to budge. Therefore I need a legal opinion on that and saw that you have experience in real estate law- not sure that applies to construction but please let me know if of interest anyway.
Thanks in advance,
Frederique
PS: i'm attaching correspondence as well as documents that seem to indicate he's wrong. There are a lot of attachments but they're short messages