I would be interested in learning a bit more about your plans for the LLC but more from a cash flow perspective, from start to finish. I may be building a home within the next couple of years and if I am able to deduct material costs that would be a tremendous boon.
However, I just can't see this working out in the end. My statement is built on a few assumptions that very well may be incorrect. Here's what I mean: The LLC purchases the materials and deducts their costs. I believe you will be using the loss from the LLC to reduce your current income from your regular occupation. That part makes sense, although I'm not sure if that works, either. The part where I get hung up comes later, at the conclusion of the build.
You have an LLC that has purchased raw materials and perhaps even hired labor to construct a home. So the LLC owns the materials at this point. How are those materials transferred from the LLC to you personally? Again, I assume you won't be purchasing them from the LLC or there would be a sale which would wipe out the loss inside the LLC.
My gut tells me that the IRS would view this as it is, an individual who is trying to deduct the cost of building his home, rather than being in the home-building business. Granted, my thought process may be way off here but that's why I'm looking for some clarification.
One final point: You have done the necessary legal steps in getting an EIN, etc (and even business cards to make things appear more valid) but the final test may be in the form of a question from the IRS. What is your contractor's license number? In MI (which, again, may be vastly different than your state) contractor's are required to be licensed. An exception to that is for a homeowner who is acting as his own GC. If the IRS requirement is for an individual to truly be in the business for which he is claiming certain deductions, this may hang you up rather quickly.