A few months ago, we were, in retrospect, ridiculously optimistic about how quickly we could finalize our house plans and get financing in order.

We finally close on our construction loan this week, and then our builder can start clearing trees, so he can do the survey and get the permit. We are building in a place where getting a permit is pretty simple, so there's every reason to believe we could break ground in March. However, if we hold off until April, it will no longer be considered a "winter build" and we can save $5-8k in added expenses for things like heating the ground before they dig the utility trench, or heating the concrete to make sure it cures correctly. Despite our having signed a contract agreeing to pay winter costs, our builder is fine with delaying and passing the savings on to us.

I'm guessing that when it stops being "winter build" time is more a function of the temperature than the calendar? Or is there a rule of thumb that they follow?

Aside from having to find someplace new to live when our current rental kicks us out (they don't want to be looking for renters in the fall), are there any major disadvantages to building in Spring? There are likely to be strong thunderstorms-- we get those every year. I think if we charged forward we might have the house enclosed before the worst of them.

We are building in Minnesota, so even in April, it may snow and be below freezing, but we've started seeing the temperature get above freezing on a regular basis now (maple sugaring season!).

Thanks for any help!