Building regulations certificate missing

[Mel65]

I bought a flat in nov2006 and the previous owner did an alteration (removal of a door from the living room and kitchen) in order to have an open layout. At the time of the work in 2004 the owner obtained a licence for alteration by the management company surveyor. When I moved in the property I made some alterations and my builder suggested that ther was no need to apply for building regulation certificate as there was no structural work.
Now I am trying to sell the flat and the management company has demanded a licence for alterations. They sent a surveyor and he is claiming that the layout is not conform with building regulation, due to the removal of doors between the living room and the stairs which are the only way to exit the flat. In addition he believes that a building regulation should have been obtained for the work done after having bought the flat.
Is the management company responsible (or it's surveyor) for having delivered a licence for alter in 2004 whereas now it is saying that it doesn't comply with building reg.?
And how can I sort out the issue with the lack of building regulation certificate for the work my builder did in 2006? As it is more than 4 years is there a risk for the buyer to be notified by council ? Or shall I propose to the buyer that he subscribes for an insurance policy .
Many thanks for the feedback you could provide.

[Richard Webster]

A consent from the management company is one thing, compliance with the building regualtions is another.

It is difficult to tell but there could be fire safety implicaitons in the removal of a door, which could mean that you have to do other things to comply with the regulations

I would suggest you telephone another local council's building control department and describe your circumstances as a hypothetical case and see if you can get a building inspector to tell you why you might need to comply with the regulations and what you are likely to have to do to comply.

Do not talk to your council's building control and do not give them the address!

[Mel65]

Thank you.