I would amend the 2015 tax return (to retract the Sec 179 $7800 deduction). If you have "placed the house into service" in 2016, I would add the $7800 plus the $28500 together ($36300) as the cost basis to begin depreciation. I highly recommend reviewing this IRS publication 551. I've provided a link below;
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/p551.pdf">https://www.irs.gov/pub/irs-pdf/p551.pdf</a>
