What happens to expenses if I move into rental property?

[Jennifer Stanovich]

I am buying a rental house with proceeds from the sale of a rental duplex.  I plan to renovate the house.  There is a possibility I will ultimately move into the rental and sell my current residence.  I know I would then have to pay the deferred taxes from the sale of the duplex but what happens to the expenses I took on the rental house during the renovation?  What do I need to do to still qualify for the tax deduction on the expenses?  Do I have to rent it for a certain period of time before I move in?  If so, what happens if I can't find renters and move in without having rented it?  

Thanks for your help!