Converted house

[Abc12333]

There are 2 pictures, one house - ground floor conversion made to the garage abd second is without any changes made to the building. What documents should I require from the vendor to be sure the work done was completed with regulations?

If you're buying this, your solicitor should know. You would definitely need to ensure it had buildings regulations sign off, and also any relevant planning permission for a start.

Building regs for the garage
Especially because
They are a fire risk and need additional fire protection

Assume the garage floor is 100mm lower than the adjoining ground floor level too.

It has to be for compliance

I am assuming that the pictures are of two different houses, otherwise it's much more than a garage conversion - stairs relocated etc.

Definitely need BReg certificate for the conversion.
The garage conversion may have needed PP if there was a condition on the original permission for the house requiring it be retained as a garage.