Frugal Framing

Carpenters love wood. The smell of fresh sawdust on a crisp fall morning, the slap and ring of hammers on boards, the sturdy feel of a new house frame—what's not to love?

So it's no surprise that when we set out to frame a home, sometimes we use a little more lumber than we really need. Sometimes we use a lot more. And sometimes, as building scientist Joe Lstiburek puts it, framers use wood like drunken sailors spending their paychecks on shore leave.

But wood isn't free, or even cheap. It has a cost in dollars, in forested acres logged, and in natural ecosystems disrupted. Over-framed walls also leak more energy—enough to show up on fuel bills, and to make a difference in comfort. And there's a labor cost: more sticks to handle, more cuts to make, and more nails to pound.

Other things being equal, economizing on framing lumber makes a lot of sense. For builders willing to learn, there are proven ways to cut back on unnecessary framing lumber use, without compromising structural strength—and while saving energy.

Around the country, a handful of leading builders are fine-tuning their building shells to save both lumber and energy. For companies such as New Town Builders of Denver and Veridian Homes of Madison, Wis., advanced framing is just one part of a larger concept.

ENOUGH ALREADY: If framing details aren't spelled out, framers may run amok, observes building scientist Joseph Lstiburek. He jokes, “If four studs are good (above, left), than five studs must be better (center), and nine studs (right) must be best of all!”

“We started off as a member of Colorado's Built Green program,” explains Bill Rectanus, New Town's manager of building systems and technologies (referring to a state-wide environmentally friendly building initiative sponsored by the state HBA). “Then, we set a strategic planning goal to be the market leader in energy efficiency. We wanted our brand to be associated with an energy-efficient house that's durable and comfortable.”

For third-party verification, New Town turned to Masco Corp.'s Environments For Living (EFL) program, aiming to qualify for EFL's “Diamond” class (the top tier). In addition, New Town hired a nationally known consultant, Bexley, Ohio–based 3-D Building Solutions, to pilot the company through the reinvention of its building systems.

3-D is a partnership of Nathan Yost, Peter Yost, and Steven Baczek, three alumni from engineer Joe Lstiburek and architect Betsy Pettit's Building Science Corp. Says Rectanus: “That gang has helped us really revise the way we build a house, starting with best-practice details, all the way through high-performance building and whole-systems thinking for the house.” One key to the approach, says Rectanus, is efficient framing methods.

It took New Town a year and a half to rethink its building systems, redraw all its plans, and rewrite all its scopes of work, says Rectanus, “and we've just finished rebidding all of those out and have completed our first handful of Diamond-class–level houses.”

Veridian Homes is going through a similar evolution. A leader in Wisconsin's Green Built Home program (a green-building program similar to Colorado's program and to others now taking hold in many states), Veridian has been working for years with Norwalk, Conn.–based consultant Steven Winter Associates in the U.S. Department of Energy's Building America program. All Veridian's homes earn the Energy Star label. And in 2006, the builder completed six homes as part of the U.S. Green Building Council's LEED for Homes pilot program, an ambitious and strict grading system that requires third-party verification of a whole cookbook of environmentally friendly construction practices.

While they like the idea, Veridian execs haven't yet decided whether to pursue LEED for Homes verification on every home Veridian builds. And the company also hasn't completely adopted advanced framing. “We've picked up some of the secrets,” explains Gary Zajicek, Veridian's vice president for construction, “but we're still working on some areas where we could really make this thing fly.”

MULTIPLE CHOICE: Steve Baczek of 3-D Building Solutions supplies builder clients with dozens of drawings in PDF format, illustrating appropriate framing, insulating, air-sealing, and rain-shedding details. Shown here are three of Baczek's options for constructing a common assembly: the intersection of a 2x4 interior partition wall with an insulated exterior 2x6 wall. Alternative 1 uses a 1x6 backer applied to the back side of the end 2x4 stud; drywall is fastened to the 1x6 at the inside corners. Alternative 2 provides for horizontal ladder blocking to be placed inside the exterior wall stud cavity. The end stud of the 2x4 wall is fastened to the ladder blocking, and the horizontal blocks provide an attachment point for dry-wall screws at the inside corner joint. Alternative 3, like alternative 2, uses horizontal ladder blocking, but the exterior wall is insulated and drywalled before the interior wall frame is butted to it, so that the gypsum wallboard is continuous behind the joint (which helps the drywall work as an effective air barrier at that corner).

For example, Steven Winter is helping Veridian re-engineer its plans to allow stack framing, “lining up our floor system I-joists with our studs and our trusses,” says Zajicek. “Right now, we set floor joists at 19.2 inches on center and wall studs and trusses at 2-foot centers. But we'd like to have our floor joists centered at 2 feet as well so we have optimum line-up for our mechanical systems.” (In that case, wall framers could also pare down to a single top plate. See “Streamlining the Structure,” page 254.)

Both New Town and Veridian are production builders, completing hundreds of homes a year from standard plans, using trade contractor labor. So for each company, standardizing and communicating its framing and insulation practices is a continuing challenge, and introducing new, unfamiliar methods adds yet another twist. As they change their ways of building, both builders have had to retrain their on-site labor forces in the modified methods. But first, each builder has had to make its own decisions about just how to update its standard framing systems.

Most beginning frame carpenters learn the same simple routine on the job: studs 16 inches on center, with doubled or tripled 2x8s, 2x10s, or 2x12s for headers. The bigger the header, the more jack studs you place to support it and the more king studs you set next to the opening—and when in doubt, one more won't hurt.

WARM AND SNUG: Eliminating unnecessary cripples under the rough windowsill leaves more room for insulation. It takes time to educate framers about small, but important, energy-efficient details such as this, says New Town Homes' Bill Rectanus.

Advanced framing takes a little more thought and some relearning—and good drawings are important, too. Registered architect Steven Baczek produces the detail drawings, such as the examples shown above, for 3-D Building Solutions. “There's no set-in-stone procedure,” says Baczek. “We have at least 40 different details builders can use, and it's up to the builder. One builder might choose these 16 details and run with them, another builder might choose these 24.”

New Town took Baczek's drawings into a meeting with the company's architects. “We sat down and went through all the details,” says Rectanus. “We said, ‘OK, let's use choice one on this detail, choice two on this detail, choice three on this detail'—and then they incorporated those into the blueprints for every plan we build.”

Now, New Town is phasing in the system on its half dozen Denver developments. “You find yourself concentrating first on the details that deliver the most bang for the buck,” says Rectanus, “and on the ones that are going to cause you the greatest problem if they aren't done right.” For instance, 2-foot on-center spacing is easy to pick up; but other details, such as two-stud wall corners or right-sized headers, are more complicated.

• Two-stud corners. Traditional framing uses three studs, and often some added blocking, to frame a corner where two walls intersect. That assembly is hard to insulate and wastes wood, say building scientists—and there are many better alternatives. Veridian Homes trains its drywallers to use drywall clips at that corner location (for product examples, see www.prest-on.com or www.thenailer.com). But Rectanus says that most of New Town's drywall companies don't like the clips. “So having a framer put in an extra piece of 1x backing seems to be easier on the job,” he notes, “and it still lets us get plenty of insulation in there.” Baczek points to other variations, as well. “I've also seen guys use corner bead, inverted,” he says. “There must be 10 or 12 different ways to do that corner.”

• Many builders resist the notion of pared-down corners, Baczek notes. “Builders take pride in saying, ‘I build a nice, sound house. It's got to be solid.'” But that's a misconception, he says: “Drywall really wants a flexible corner—because the wood is certainly going to move at a different rate than the drywall.”

  Over-fastening drywall can be a recipe for cracks and callbacks, agrees Veridian's Zajicek, especially at wall-to-ceiling joints: “The top part of the attic truss will move differently than the part that is surrounded by insulation and conditioned. And that creates a lot of stress on the wall/ceiling line. So we don't even put nailers at the ceiling line—we just clip the drywall to the wall and let it float.”

• Right-sized headers. Stud spacing is key in a clear wall section (a wall area composed of just studs and insulation, with no framed-out openings or other extra framing). But window and door framing can still load up the wall with extra wood. “Some engineers will say, ‘OK, your biggest header in this house is a triple 2x12, so we'll just put a triple 2x12 everywhere. That way, the framer doesn't have to worry about getting it wrong,'” Rectanus explains. “But we said, ‘Absolutely not. If it's a double, I want a double. If it's a 2x6, I want a 2x6.' You size them right to minimize the excessive lumber usage.”

• Better still, says Rectanus, designers can switch to engineered lumber headers. “Forget all these different sizes—I can use a single-ply 1 ¾ x 8 or a 1 ¾ x 6 LVL [laminated veneer lumber] on every header. Then, I can put foam insulation on the back side of that and really increase insulation value.”

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.”

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 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.”

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.