Thank you for the responses.
Shane - we did something similar when purchasing our first home, however that was in 2007 so things were different then. I am glad so see that things are still similar and closing would be contingent on paying off car note. I will still make sure to only have about $2k left on the note at pre-approval, then I can just make normal payments during the build process and it will be paid by closing.
Startingover10 - I realized what you meant, it was me that was unclear when stating just mortgage payment, I did mean PITI, but they are not always one and the same.
Now I just sit here and wait for my current house to sell, wish I could control that as much as the car loan payoff timing!