A further step is to use steel hangers, rather than jack studs, to support headers. Veridian Homes does that, but New Town doesn't. Explains Rectanus: “We have such high wind loads in Colorado that the larger openings require extra studs anyway, just to maintain the shear value of the building. In some cases, the opening needs two or even three king studs. You can't get away from the engineering.”TEACHING THE TRADES
When you introduce a new bag of tricks, you've got to do some explaining to your help. Veridian puts all its trade contractors through a formal training program, says Zajicek. “We have a scope of work made up for each trade, with written explanations and photos of each activity they have to perform. We'll sit down with a drywall or framing contractor and review the whole scope of work, line by line and photo by photo—not just with the owner, but with all his people who are going to work on our jobsite. So all the way down the ladder, they know what we're expecting and the process to get there.”
ALL ZIPPED UP: Applying systems thinking, advanced builders can devise energy-efficient details that are also quick and simple to build. The right-sized structural header above this window is now buried behind fiberglass from the “blown-in-batt” insulation system.
Certain details are harder to get across than others. “The single top plate can be kind of a hard sell,” says Baczek. But Rectanus says his framers have adapted readily. “I thought I would have a lot more trouble getting the framers to buy into this than I did,” he says. “I was very pleased with how well it was accepted.”
It's not all smooth sailing, though: “The first several houses, we had to work through the details a little and make sure they understood,” says Rectanus. “For example, when you do a windowsill, a lot of times it's a practice to get jacks on each side and then put a couple of cripples in under the bottom sill. Well, there's no need for cripples. Fine-tuning it, and pulling those extra sticks out where we can, was where we had to do the work. But they bought into the overall concept of it right away.”LESS IS MORE
Less wood in the wall means more money in the bank for builders—and for homeowners.
Builders who switch to advanced framing reap savings on labor and materials, but the full benefit may not materialize right away. “As we first start to bid these [jobs] out, the prices from our framers are not coming in that much cheaper,” says New Town Builders' Bill Rectanus, “because people are still unsure about pricing something they aren't used to doing.” New Town has switched to doing takeoffs internally—“we know full well that there is a lot less lumber in that building,” says Rectanus—and the lumber costs are dropping. “But I think the overall framing number is still not as low as it could eventually go when these guys get more used to these techniques,” he adds.
For homeowners, too, the new methods will pay off long-term. Less wood in the wall means a better-insulated structure: “Every time you pull out an R-1 value piece of lumber, you're putting in an R-3.5 value piece of insulation,” says Rectanus. Fewer studs also means fewer chances to make mistakes, notes Veridian Homes' Gary Zajicek. “Each time your insulation batt touches a stud, that batt has the potential to be installed incorrectly.” Two-foot spacing automatically reduces those occasional flaws.
How much does all that matter? A lot, says Zajicek. “Our research with Building America shows that if we build a 2x4 wall with studs 2 feet on center and compare that with a 2x6 wall with studs 16 inches on center—using the same material for insulation—the thinner wall with the greater stud spacing will outperform the thicker wall.”STREAMLINING THE STRUCTURE
Continuous load paths make the best use of load-bearing materials.
Advanced framing is more than a set of details—it's a system. In its fullest form, the system applies engineering to every element of the frame. The key is continuous load paths: roof framing, wall studs, and floor joists lined up from ridge to foundation.
“That's where the value engineering really comes into play,” says Veridian Homes' Gary Zajicek, “when you're at 2-foot on center all the way through and your openings are all spaced to make that work.” With an engineered band joist helping to carry wall loads or point loads around openings, headers can be smaller. For narrow openings, no structural header at all may be required. Doubling the band joist above larger openings is another way to eliminate the header and simplify the wall framing.
A further refinement is to locate windows or doors based on a 2-foot modular layout, so that rough-opening jacks fall out naturally at stud locations. But aesthetics may limit that strategy. Says Bill Rectanus of New Town Builders: “No matter how well you design the house for efficiency and comfort, you still have to have a good floor plan and a good elevation. The most energy-efficient house in the world won't sell if it's not aesthetically pleasing.”
For now, New Town has modified the framing of its existing plans as much as is possible without changing the houses' appearance. “We didn't want to mess with the exterior elevations,” notes Rectanus. “The cities had already approved them, and we were already building them on these jobsites. So we didn't tackle that with this first round.”
In future years, the builder's new plans may use modular layouts. But appearance will still count: “Where it frankly just doesn't work for the architecture, we're just going to have to skootch that window or door over and make it work,” Rectanus says.