Sleeping in under construction home permit Homeowner Exclusion exemption?

[Matthew Thomas]

Aloha, I have a tiny vacant lot that I will build a home on during the next 2 years. Start December '14, finish December '16. My question; if I begin living on the property in a tent, as of next week, then in 2017, when I sell the house, will I be able to exclude the gain? I will sleep in the under-construction house during as soon as the roof is in place. Is it possible to ask the IRS for a ruling in advance of my action?