Form 936 states that, "A taxpayer who enters into a written binding contract before December 15, 2017, to close on the purchase of a principal residence before January 1, 2018, and who purchases such residence before April 1, 2018, is considered to have incurred the home acquisition debt prior to December 16, 2017."

In our case, we signed our purchase and sale agreement with the builder in September 20, 2017. In the agreement, the estimated date of substantial completion was listed as "Dec 2017 - Jan 2018".  (exactly as written here)

We actually closed on the house (ie, signed off on the bank loan and all other agreements, got the keys to the house) in March 1, 2018.

I'm thinking in this case we should qualify for the exception?