I've had about a half dozen or so, of these new house deals and I have taken the H.O. to MY bank for a credit check and had the H.O. use my bank for financing. It works for me and the bank likes it because I'm bringing them more business. I have worked a few deals with the banker to put some "seed" money up front to get any extra materials for the job that I don't normally have around the shop, if the H.O. has the proper line of credit. The bank also gives the H.O. a bit of a break on interest rates as well, so everyone wins a bit.
The best part is that I can rest easy when I know I won't be getting stiffed for the work because the banker has done all the background stuff on the client before the real work starts and I know the H.O. actually does have a valid credit rating.
As to your estimating of the job, that's a whole other issue. I have a very good supplier that wants to sell his stuff so he keeps me up to date on prices about once a week.
A 3,000 square foot house around here in Alberta will probably take about $3.50 to $4.00 per square foot for the material. I charge by the hour on these kinds of jobs, so you can work out an estimated time for your work. It helps a lot to have a helper for new stuff and NEVER do the rough-in until the lugans are done with plumbing and HVAC.
New house construction pricing takes a LOT of detailed work. I have even added up the price of cable staples into my work. Estimating is an artform to me and I ususally add a cushion for those ever present "unknowns" that always come up. I use 10% and it's never gone south on me yet. The only job that I took that went over estimate went over by 1.5%, which I agreed to eat because I won't back out on a contract price.
Hope that helps.
