To do this work I (obviously) need to get a structural engineer to check that this new load I am introducing can be supported by the current construction.
As the property was a fairly recent conversion, is it
a) possible to get the complete technical description of the original build from my local BCO?
b) allowed to use the fact that this build was checked by the BI to assume that the building does actually meet the stated spec or is it still necessary to "open up" the build to check?
And in case you are confused by my asking this, the building is built on a, presumably reinforced, concrete raft not directly on foundations built into to the ground. Obviously this raft is supported by foundations, but I can't change those nor do I think that I'll be allowed by the owner of the rest of the building to "open up" this raft, so will be somewhat stuck if this is necessary.