Reimbursement of building expert costs?

If he finds no defects, then ...

...it is a bad building savings contract.

Or there are none! Of course, a building without any defects will almost never exist, but certainly buildings where only minor issues occur. But just because he finds nothing, saying it would be a bad building savings contract is, in my opinion, nonsensical.

A good building savings contract always finds something. They don't have to be bad things, some can be fixed right on the spot, some you can do yourself. Some might just be small improvements, where, for example, a gap in the intermediate ceiling can still be stuffed with a leftover piece of glass wool, and so on and so forth. If it finds nothing, it is not looking properly or is on the payroll of the (e.g.) general contractor.

In the context of a legal dispute, you might have chances of cost reimbursement. Before that, your chances are slim.

The building savings contract will find something, even if it is the poor joint.

I try to take the question seriously (not exactly easy), yes you have to pay it and no you will not get anything refunded.