Most cost effective new build spec type

[Wade Stahle]

Ok seasoned spec builders,

What is your most cost effective/profitable home plan? In other words what building type uses the least amount of material, yet still gets high $ per sq. ft? Ranch, split-entry, two-story, tri-level, etc. If anyone has any floor plans they'd be willing to share that would be great also.

[J Scott]

Two big rules of thumb:

Generally speaking, the more square the house, the cheaper to frame and roof.  

The more open space (square footage), the cheaper the per-square-foot cost.