RENTAL EXPENSES FOR PROPERTY NOT RENTED

If it is not available for rent yet, there is nothing to deduct or depreciate.  It waits until it is available to rent.

If you have spent over $100,000 on it, I suspect that a large part of that is actually an "improvement", which is added to the Basis of the property.

For non-improvements, then either (a) if it is an 'investment' property for the production of income, all expenses prior to it being available are added to the Basis, or (b) if the rental rises to the level of a "trade or business", those non-improvement costs are part of "Startup Costs".

But back up.  You have real estate in a corporation?  That is usually a bad idea.  You should probably consult a good tax professional and a lawyer about this setup.