Is there any relationship between fire protection reporting and the nature of use of the house?

The purpose of each new building is specified when the planning permission certificate is obtained. For example, if you want to convert a large underground space that was originally used as an underground garage into a supermarket or entertainment venue, it will definitely not be allowed unless you apply to change the planned use nature. Based on your situation, I think it should be possible, because the original use was for public entertainment venues, and now it is converted into a supermarket, and the fire protection requirements will not be stricter than before.