Personal Financing Guidance

[Daniel Bloomfield]

My wife and I are in the process of looking into building a new house. The house would include an apartment above the garage which my father-in-law would stay in for the foreseeable future, though down the road would provide us with the possibility for an EDU or home expansion. My father-in-law has offered to provide the money to build the garage/apartment which would be used as the down payment for the overall house for my wife and I. With my limited knowledge on this, I believe anything over 15k would result in a gift tax which the amount for this would be above. I believe the only way to avoid this is if my father-in-law was also on the deed/loan though I was wondering if there are any other/better options for this scenario?

Thanks in advance, any guidance at all is greatly appreciated!