[special-K]

Yeah, never pay in full before completion. In Maryland we can take a 33% deposit upon signing a contract. But, if I stock some materials, set up equipment, or commence any wok before signing I can ask for more, like 50%. I'll do that on a bigger job that's heavy on the materials. It works both ways, I don't want to get stuck paying for someone's materials. Normally I do 1/3 down, 1/3 at 50% complete (always clearly defined), balance upon completion. I give actual amount in parenthesis after each draw. I go heavy on materials, other costs, and light in my pocket through the first two draws. I try to have little to no expenses from my final draw.
At 50% down I get 30% at halfway, so 20% is owed at end. It works out best for everyone. The homeowner never puts more than 1/3 out into the wind and if they are seeing me they are seeing that money spent.

Anyone building one where it gets cold enough to need heat, do yourself a favor and run heat in the slab. If you can heat with wood, an outside wood burner can do the trick for your shop and house. A privy is about a must in a proper shop