<<How would you allocate the cost of utilities to build the house separate from costs to maintain the home?>>
the OP would have to come up with an allocation that would be defensible in an audit. For example, until the AC units (or heating units, depending on where in the country this OP is) were installed and operational, and the home was enclosed, it could be quite defensible that 100% of the power costs were related to building out the house...after that I agree it gets 'squishier'. Once the certificate of occupancy was issued, then it would be hard to defend anything other than 'zero'.
