We just finished a year long project in which we remodeled the existing house, new siding, new roof, new floors, and added a 1600 sq ft addition. Our totals were about 75$ a sq/ft. The major cost savings was being our own g.c. One problem we encountered was finding a bank to finance the construction. Most wanted a builder of record. The bids we received from builders/general contractors ranged from 125$-180$ per sq ft.