IT'S A CLICHÉ THAT THE PACE OF CHANGE IN home building is glacial. That's only partly true. Actually, builders will embrace any change that solves a problem or saves time or money. Some new technologies, like cell phones, become ubiquitous seemingly overnight. Others take more time, but do gain a foothold. I-joists come to mind. “I remember 14 years ago when Trus Joist was trying to introduce wood I-joists into the market and nobody wanted to hear about it,” recalls Boise, Idaho, builder Chuck Miller. “Now, you won't find a job that uses dimensional lumber.”

Where are the next I-joists? Innovation in home building is like that in any industry, according to Dana Bres, a research engineer with The Partnership for Advancing Technology in Housing (PATH), a government-industry consortium based in Washington. “At first, a handful of early adopters embrace a new technology, whether an I-joist or an Edsel,” he says. Win some, lose some. But those products that prove their worth and gain a critical number of converts—say, 15 percent to 30 percent of the market—suddenly burst into the mainstream with a flood of new users. Bres calls that the “tipping point.”

PATH recently identified 10 emerging products and practices it believes are near that point. We talked with builders who are using seven of them, to find out what benefits they offer, what their prospects are, and what they say about the future of home building.

Low-Impact Development: Keep The Lid On

I LOVE TO TURN ABANDONED ROADS WITH stone walls into walking trails,” says Steven Lewis of SLI Consulting, an Atkinson, N.H., land development company. Lewis is an advocate of low-impact development (LID). His projects consist of clusters of homes on small lots, with up to 60 percent of the land preserved as open space, including wooded trails and community gardens. Houses are carefully placed, with large ones on flat areas, and small ones on rises. Roads are narrow and winding, and instead of storm drains, natural water-management features, such as roadside grass swales lined with rock, slow down runoff so it can seep into the ground.

Clustered homes and small streets reduce infrastructure costs. There's no water runoff for the town to deal with. And most homes sell for more than they would in a traditional development. “Nontraditional development is cheaper for the town, and the developer competes better,” Lewis says. It sounds like a win for everyone.

But not everyone sees it that way. In the late 1980s, when Lewis proposed his first LID project, Bryant Woods in Atkinson, the town denied it, citing a three-acre zoning requirement. When he failed to get a variance, Lewis went to court, charging that the zoning discriminated on the basis of income. The suit took four years, but he won, and the project went ahead.

His experience isn't unusual. Bielinski Homes in Wausau, Wis., just started work on its Prairie Glen “conservation development” in Germantown, not far from Milwaukee. Jack Broughton, director of environmental policy, says approval took four years but should have only taken one.

“Planning and zoning officials have a mind-set about how subdivisions and communities need to look,” says Lewis. But he adds that the biggest hurdle is general hostility toward developers. “People are suspicious of your motives.”

Fortunately, change is in the air. Lewis now finds widespread support for LID, and subsequent projects in Atkinson and nearby Salem were quickly approved. It doesn't hurt that he has allied himself with historical societies and other community organizations. “You give 10 acres to the conservation commission, and it's tough for them to put a black hat on you,” he says.

States are also seeing LID as a way to preserve the rural character of small towns. The challenge lies in bringing the towns along. Broughton says that while Wisconsin now encourages and promotes LID, some municipalities have been slow to revise their zoning regulations to permit it. “It's municipality by municipality,” says Broughton. “Like any other evangelical movement, you win converts one by one.”

Shallow Foundations: Frosty Reception

MANY NEW BUILDING TECHNIQUES ALSO face resistance. One that has prevailed is the frost-protected shallow foundation, or FPSF, for slab-on-grade homes. Rather than the 3- or 4-foot-deep footings typical in cold climates, it consists of 12-inch-deep stem walls wrapped with rigid foam insulation. This raises the frost line around the foundation to just below the surface. The builder saves money on excavation, formwork, and concrete. And estimates of the time saved range from two days to two weeks.

While FPSFs have a proven track record (Scandinavian builders have used them for decades), code officials have been skeptical. Spirit Lake, Iowa, builder Bill Eich has been using them since the mid-1980s. He builds about 15 homes per year on shallow foundations and also uses FPS-Fs for garages and walk-out portions of basements. He says most of the builders in his market have followed suit, but when he first started presenting the technique to them, the standard response was, “My inspector will never buy that.”

That's less of a problem now. The new International Residential Code includes specs for shallow foundations, leading more builders to give them a try. Kansas City, Mo., builder Tom Woods used them for 30 of the 87 homes he built last year and, like Eich, he now gets inquiries from other builders, including a large Indianapolis production builder who plans on trying FPSFs this summer.

The only resistance Woods got was from his foundation sub. “He said it would be too hard to hold the forms in place or something like that,” he recalls. “So we took one of our framing crews and used them to set the first set of forms.” Too bad for the sub. Woods says that he saved so much money he no longer uses a subcontractor for shallow foundations. His framing crew does it all.

Precast Concrete Foundations: Speedy Setting>

A PRECAST CONCRETE FOUNDATION IS simply a concrete stud wall. Reinforced concrete studs and lintels support the home's weight, while the spaces between the studs are easily filled with insulation. Wood strips on the stud faces make it easy to attach drywall.

Though a precast foundation costs more than a poured one, it goes in a lot faster. In the North, you can set a foundation in the coldest weather. And builders swear by the quality: The 5,000-pounds-per-square-inch concrete these walls use is nearly impervious to water, making them a great choice where groundwater is a problem or where people like to finish off basements.

Ephrata, Pa., builder Rich Hurst has used precast walls from Superior Walls of America in New Holland, Pa., for about 100 homes. His crew can install two foundations in a day. “I haven't used poured walls in years, and where there are water issues, I only use Superior walls,” he says. He considers the $2,500 (on average) that it adds to his 2,500-square-foot homes money well spent. “It's more expensive, but my phone never rings after a storm.”

Lancaster, Pa., builder Mike Cahill also offers his customers precast concrete foundations, stressing their water resistance and the ease of finishing the basement. “I tell them they're either going to pay now or later to have the basement finished,” he says. The result: In January, buyers chose precast for 47 of the 57 homes he sold.

Structural Insulated Panels: Strong Silent Type

STRUCTURAL INSULATED PANELS (SIPs)— sandwiches of foam insulation packed between two OSB facings—let builders create a well-insulated, airtight shell in a fraction of the time required by stick building. “SIPs are great,” says Dick Brown, co-owner of Carl Franklin Homes in Dallas. “They're strong, they're quiet, and by making it easy to do cathedral ceilings, they let us create large, spacious rooms.”

But SIPs have been slow to catch on. “They aren't the best example of a mature building technology,” says Bill Zoeller of Steven Winter Associates, an architectural and engineering firm in Norwalk, Conn., that's been part of the Building America program, a government/industry partnership that helps production builders evaluate new building techniques. “They're not a complete system. The electrician shows up and scratches his head.” As for airtightness, “when you start putting panels together, the joints aren't necessarily sealed,” he says.

Brown says that while there is a learning curve with SIPS, “once a crew gets the hang of them, they go up very quickly.” In fact, he likes them so much that all 100 homes his company builds this year will use them.

He does caution that the panels must be correctly detailed. He found this out after completing his first SIP homes. Some homeowners complained about loud bangs—“like a gun going off in the house”—waking them up at night. The cause? Panel movement. SIPs are made by laminating materials that expand and contract at different rates, and the extreme temperature difference between inside and outside during the hot Texas summer caused enough movement to shear off some drywall screws.

Brown says that he spent three years learning how to correctly detail SIP houses. And while he declines to share his experience (he does train other builders for a fee), chances are his method has to do with controlling a house's moisture. “Proper conditioning of the home is the key with SIPs,” says architect Betsy Pettit, a principal with Building Science Corp., a building science consulting company in Westford, Mass., which has also been a Building America participant. “Every building material will perform better and last longer if there's the same relative humidity on either side.”

HVAC Optimization: Less Is Better HVAC OPTIMIZATION IS NOTHING more—or less—than the proper sizing of a mechanical system. “It's old news,” says Building Science's Pettit. “We've been telling builders about this for 10 years. Everyone knows they need to do it. Everyone knows there are penalties for oversizing an air-conditioning system. The top 10 builders are trying to get their systems [sized right].” But only half of the production builders she works with are on board.

Here, as with FPSFs, the strongest opposition comes from subcontractors—in this case, HVAC subs who insist on using rules of thumb that may not even apply to today's tight building envelopes and efficient mechanical systems. “They're worried about diminished airflows,” says Zoeller. “And they cling to the idea that they need a certain cfm of airflow per square foot.”

Builders who succeed with optimization work with their subcontractor on system sizing. “It's my name on the company and the house. I don't want to rely on someone else,” says builder Miller. To do optimization right, he points out, you need to understand how heat and moisture move around a house and carefully detail the house to manage those elements. “Sizing is part of the systems approach to home building,” he says. He, too, found subs skeptical. “I went through three HVAC contractors before I found one who was willing to buy in.” But he believes it was worth it. “This is the right way to build a house,” he insists.

With no energy crisis, some builders question whether the benefits of optimization outweigh the hassles of bringing subs around. Miller thinks so. His homes' thermal comfort brings referrals from happy customers, he says. “You won't hear my customers complaining that the second floor is 10 degrees warmer than the first floor in the summer.”

> Home-Run Plumbing: Flex Your Pex

A SCHEMATIC OF A HOME-RUN PLUMBING system looks a lot like an Ethernet net- work. Hot and cold water supplies run to a central manifold. Hot and cold PEX (poly-ethylene) lines connect the manifold to individual fixtures, with every fixture getting a dedicated pair of lines.

Homeowners like being able to shut off individual fixtures quickly at the manifold. And PEX is a great choice in areas with “aggressive” water—water with low pH levels, dissolved carbon dioxide, or hydrogen sulfide from decaying plants, all of which can eat away at copper pipe. In fact, most large builders are using PEX in one market or another. “Everyone is going to PEX in Las Vegas,” notes Robert Blazek, president of the Las Vegas division of Executive Plumbing and Heating. He lauds the fact that there's no soldering and, therefore, no need for torches. “Our insurance company really likes that.” And installation is simpler than with copper. You need only one skilled laborer to connect the lines to the fixtures; a helper can easily snake the lines through walls and floors.

Builders who choose this technology should make sure their plumber is up to speed on its requirements, notes Dave Yates, a plumbing contractor in York, Pa. For instance, the plumber needs to watch required flow rates for things like high-flow shower faucets. Yates recently had to alter a home-run system where the installing contractor ignored that requirement. “The high-flow shower faucet was starved for water, and the temperature couldn't be regulated accurately because of pressure fluctuations when other fixtures in the home were used,” he says.

Tankless Water Heaters: Hot On Demand

TANKLESS—“INSTANT”—WATER HEATERS HEAT WATER only when a fixture is calling for it. It can easily supply all the hot water for a small home, using less power than a tank. In a large home, it can provide instant hot water at fixtures at the opposite end of the house from the hot water tank. Carl Franklin Homes offers tankless as an option, and about half of the company's buyers choose it. “Homeowners like it because they don't waste water waiting for it to heat up. It's not an emergency need, but it does raise the quality of housing,” says co-owner Dick Brown.

While tankless water heaters seem like a clear winner, problems with early models hurt their reputation.

Brown's company started using them four years ago. “I had very mixed emotions at first,” he recalls. “My brother Steve wanted to try them, but I didn't.” There were problems. Not only did the first units fail to get the water hot enough, but there was a series of water leaks. “One day, we got a call from a lady who said she had water dripping through her ceiling. I was at the point of saying ‘no more,'” Brown says. Seisco, the company that made the units, asked Brown for one more chance with a new model. He's glad he said yes. “That was a year and a half ago and we have had no problems since. In my opinion, the technology is now refined and reliable.”

PATH researchers used one of Brown's homes as a lab to test the technology, installing a Seisco unit next to a conventional tank. They used a computer-controlled valve to remotely switch the home's origin of hot water back and forth between the two sources, while logging the electricity used by each. The results showed that the tankless heater could save a five-person family several hundred dollars per year in electricity. The test-family members liked it for another reason: There were several times they ran out of water, and Brown says they understood those times to be when they were on the tank. When the trial ended, the family chose to keep the tankless.

What's Next?: Coming Down The Pike BRES AND HIS PATH COLLEAGUES POINT out that their top 10 list focuses on innovations likely to hit the “tipping point” in the near future—within two to five years. Even bigger changes are coming in the next 10 to 15 years.

PATH recently compiled another list, this one containing 18 products and processes they predict will “tip” in the next decade, given current trends. Many are logical extensions of the top 10: PATH researchers believe more builders will embrace factory-built components, that water-conservation techniques may be the only way builders can get permits in some Southwestern areas, and that more builders will see energy efficiency as a way to differentiate themselves. That is, until the market tips and builders have to use these innovations to keep up with the competition. Then the early adopters will move on to the next frontier.

Charlie Wardell is a freelance writer based in Vineyard Haven, Mass.

Ready For Primetime? The Top 10: PATH believes that these building technologies are on the edge of industry acceptance. The chart lists some of the pros and cons of each.

Ready for Primetime?
Pros Cons
Low-Impact Development Less environmental impact. Lower infrastructure costs. Increased home values. Resistance from zoning officials. Some buyers may prefer large lots.
Shallow Foundations Lower excavation and concrete costs. Reduced cycle time. Resistance from foundation subs. Training and education needed.
Precast Concrete Reduced cycle time. Imperviousness to water. Ease of finishing basement. Higher installation cost. Need a local plant. May require engineers' stamp.
Structural Insulated Panels Tight shell if properly detailed. Reduced cycle time for trained crew. Requires training. Can warp if humidity not controlled.
Hybrid Wood-Steel Framing Can reduce materials cost. Exterior insulation needed on outside walls.
HVAC Optimization Properly sized systems cost less. Monthly energy bills are lower. Many HVAC subs still rely on rules of thumb.
Home-Run PEX Plumbing Easy to install. Easy to shut off individual fixtures. Resistance to aggressive water. Resistance from plumbers and code officials. Most fittings need adapters. Need to watch water-pressure issues.
Air-Admittance Vents Reduces the number of roof vents needed. Reduces plumbing costs. Codes still require at least one vent. Vent gaskets can wear out.
Tankless Water Heaters Lower hot water costs. Instant hot water at fixtures. Higher installation cost.
Shared Wastewater Lower installation and operating costs. Improved quality of local water supply. Skeptical zoning and health officials. Requires more frequent monitoring than traditional systems.