Builders make money by saving it. The challenge is putting money in their pockets without taking it out of yours. Progressive builders are turning to advanced framing: Roof trusses, floor joists, and 2x6 walls all 24" o.c. and stacked to transfer loads. You may not see it a lot (yet), but it's important to understand the concept when you field questions about it. Here's a quick, easy-to-understand overview from nationally-known building scientist Joe Lstiburek.