Stairs in communal area in breach of building regulations

Lets say someone bought an apartment in an apartment block. They subsequently discover that the stairs in the communal area are not compliant with building regulations (they are too steep).
What are the implications? Is it sufficient (from an insurance/legal perspective) to place a large warning sign at the top & bottom of the stairs?

I presume these stairs have a pitch of more than 38 degrees? (which would be the max for semi private stairs in new buildings built now). My questions would be a) when was the apartment block built and b) how does this “someone” know that they are not compliant? (the sign, if it’s there now, doesn’t prove that it’s not compliant. It could merely be the management company being careful?).

A) it was built in 2007
B) some of the apts in the complex are in receivership. The receiver got a survey carried out that highlighted this issue.

Well the rule on the max of 38 degree pitch on semi public stairs has been there since at least the 1997 regulations so if those stairs are steeper than that yes it would seem they aren’t compliant. You can see it for yourself here,1651,en.pdf

As for the implications, that’s way above my pay grade I’m afraid.