Fixing wonky ground floor in my Victorian house

[sharrison1]

I guess I've had subsidence (?) not sure if that is the best term but my floor in the living room is wonky and slopes down. I want to get it replaced and straightened out, does anyone know of any companies that specialist in this kind of stuff? It's a suspended floor with a 1m cavity underneath so I dont know how complex it will be to resolve. Thanks in advance 

[Sue]

If you do have subsidence,  there may be other issues as well.

If you don't want to involve your insurance company, you might be better consulting a surveyor in the first instance?