Builder product choices for high-performance homes

"That product idea has all the depth of a wading pool."
- Anonymous

"Anyone who has never made a mistake has never tried anything new."
- Einstein

At some point, every builder considers changing individual products they use to build homes. From the outside looking in, the process typically seems slow and often agonizing. That's because, as the saying goes, you can sometimes recognize the pioneer builders by the number of arrows they have in their backs.

Manufacturers spend resources developing products in response to perceived needs, then push hard to gain market acceptance for their new and improved offerings. Yet at day's end, it's the builder who has to decide if a new product's benefits outweigh any added cost or risk.

Builders must wrestle with tough questions, including: will the new product outlast and outperform what it re-places? Will it be easier or harder to in-stall? Wilt crews need more training? Will there be any unintended consequences from unanticipated interactions with other products?

From the get-go, builders of systems-built, high-performance homes-in which the focus is on comfort, durability, indoor health and efficiency-seem forced to both make more key changes and make them faster than their competitors. The term "brain damage" frequently pops up in conversation.

What follows is a list of products and a couple of processes that individual builders of high-performance homes selected to make their homes work better. A few other suggestions come from an architect, an energy rater and this writer.

Rinnai Water Heater

"Our biggest change this year from what we were doing was switching to the Rinnai water heater," said Jammie Sabin, president of Aspen Homes of Colorado Inc.

The Rinnai Sabin picked is a sealed-combustion, tankless unit (also known as "instantaneous water heater," a concept used world-wide for decades). Rinnai's claims that it could supply two showers plus a third tap with continuous hot water were field-tested and verified by Aspen before the units went into new homes. Sabin says early returns from homeowners are all positive.

"The Rinnai is a great fit in a lot of ways. We were using a top-of-the-line, sealed, power-vented unit at a high cost upgrade, but we were experiencing callbacks because the inducer motors weren't performing well. The Rinnai isn't much of a cost change from what we were installing, but the boost from 62 percent to 82 percent efficiency helps us with our energy guarantee and our overall image of high performance. And when people hear about the 20- to 25-year life expectancy plus the `you won't run out of hot water when the relatives are visiting' claim, we get a 'wow!' reaction from buyers. This sets us apart."

Sabin praises a special detail on the Rinnai: its lime-condition warning. "Lime buildup is the enemy of water heaters. Over time, the Rinnai's panel will light up with an 'LC' warning for lime condition. The homeowner has to pull out a device, soak it in vinegar for 20 minutes, then slip it back in."

Grace Window Flashing

Among window flashings on the market, John Kurowski (Kurowski Development Co.) selects Grace's product due to their technical support. "They have a good field-instruction video showing installers how to integrate their window flashing with a drainage plane material," said Kurowski, "so that any water that gets past the exterior finish doesn't leak in around windows and doors."

How hard is it to do this right? Harder than you might think. Kurowski described one of his own homes where the contractor had to reflash all windows and doors because the initial flashing was installed incorrectly; any rain that penetrated past the exterior siding to the flashing would have drained down between the flashing and drainage plane, then wetted the wood below the flashing. (A personal note here: of the seven infill scrape-off homes being recently built in my neighborhood at $750,000-plus apiece, window flashing was properly integrated on only one of them.)

Kurowski also strongly recommended use of Grace's Ice and Water Shield wherever a roof has a small saddle next to a wall in an otherwise well-pitched roof. "In colder parts of Colorado, we use the Ice and Water Shield to reduce problems with ice-damming."

Different Wall Insulation

Most builders of high-performance homes revamped their wall insulation systems.

Sopris Development's Chris Easton says, "One of our better products is the wet-blown cellulose in walls, but you can only use it seasonally due to the longer drying times in cold weather. Then we switch to Optima." McStain Neighborhoods and Oakwood Homes also use a lot of cellulose, (A related aside: Oakwood's Don Carpenter says switching to dense-packed cellulose in garage ceilings virtually eliminated comfort complaints in those above-garage rooms.)

Certainteed's Optima insulation consists of fiberglass blown behind netting nailed over the interior framing. Even though Engle Homes's Jeff Vogel re-ports it costs an extra $1,000 to $1,200 to blow Optima in their walls, he swears by it. "We love the stuff. First we start with their advanced sealing package, sealing up all holes. Then all other contractors have to follow our 'you drill the hole, you fill the hole' policy to keep the shell tight. Filling the cavities with Optima helps us out thermally, plus it provides a little more noise reduction."

Aspen Homes also relies on Optima. Says Sabin, "it's such a simple solution and doesn't cost that much more. To a large degree, it eliminates a lot of the installation issues you can have with wall insulation."

Fan Cycler

Oakwood's Don Carpenter says, "The AirCycler helps us with our in-door air quality." An AirCycler controller turns on the furnace blower every half-hour or so whenever the thermostat hasn't called for either heating or cooling. A six-inch duct (typical) to the outside, hooked up to the return-air plenum, draws in out-door air and circulates it throughout the home whenever the blower is functioning.

Besides providing the home with fresh air, fan eyelers mixes air between rooms, smoothing out minor temperature differences that can build up in-doors during the day. Engle, Aspen, McStain, Sopris Development and others use an AirCycler controller as part of their indoor air quality and comfort control system.

Different Mudsill

Sopris Development switched to a Timberstrand engineered-wood product for their mudsills. Said Sopris' Easton, "the product is a lot more uniform. It doesn't warp or split and it still has the necessary resistance to moisture. And it avoids some of the problems with the new treated woods, like nail corrosion."

Foundation Seal

Oakwood likes the T-shaped air-sealing product from Protecto-Wrap called Triple Guard. It slips between the mudsill and foundation, then attaches to the frame above and foundation below the joint. The residential newsletter Energy Design Update dubbed this product "The World's Best Sill Seal" (March 2003 issue).

Justin Wilson with McStain identified the mudsill joint at "one of the two or three leakiest locations in the typical house." While McStain likes the Protecto-Wrap product, they find that in-stalling a I0-inch band of butyl-backed window flashing at this location is more cost-effective.

Foam Sheathing

Energy rater Robby Schwarz (BuiltWright Inc.) highlighted Aspen Homes' selection of 1-inch extruded foam sheathing (DOW Styrofoam) for their exterior walls. That allows Aspen's 2-by-4-inch walls to achieve R-20 thermal performance. Aspen obtains double duty from this product, as it provides a drainage plane for any water that blows past the exterior cladding. Says Schwarz, "you hear complaints about wavy siding over foam sheathing, and about its susceptibility to damage, but Aspen makes it work."

Justin Wilson reports McStain is taking another look at foam sheathing.

Sealed Combustion Furnaces

Every builder in the program uses sealed combustion furnaces for two reasons: they isolate byproducts of combustion from the home, and the 92 percent efficiency factor (typical) should cut any home's heating bill by 15 percent.

Doug Walter (Doug Walter Architects), who always promotes sealed-combustion units in his business, re-ports they can still be a hard sell with customers. "There's a lag in consumer awareness about the need for this type of product and the benefits of combustion safety."

Lifebreath Furnace

This multi-function unit can supply heated air, cooled air, and ventilation air with heat recovery (HRV). The heat source for space heating is typically provided by a high-efficiency, sealed-combustion water heater. When the thermostat calls for heat, the Lifebreath pulls hot water from the water heater, circulates it through a water-to-air heat exchanger, and the HRV's blower circulates heated air throughout the home at normal speed. When only fresh air is required, the unit operates at low speed.

Both Sabin and your writer are in-stalling Lifebreath units in their own personal homes. If the product works as advertised, Aspen Homes will consider using it in a special new product line.

Advanced Framing

Optimized Value Engineering, first publicized a couple of decades ago, saves wood and saves energy but has never gained wide acceptance with framers. Yet Oakwood, McStain, Engle and Aspen Homes are all using some elements of what is now called advanced framing.

"We started using some advanced framing in our panels about three years ago," said Oakwood's Don Carpenter. "It helps us achieve our high-performance-home objectives by enabling us to put in more insulation."

Wilson reports that elements of advanced framing in McStain's recent re-search project the Discovery House (see last month's Energy Waves column) -are already working their way into a number of their production lines.

Testing

McStain is gradually increasing the amount of performance testing in their  homes. Oakwood has someone on staff who soon will be testing 100 percent of their homes, and will bring in a third-party to verify the results in 15 percent of those homes. The battery of tests typically measures house tightness, duct tightness, room-by-room air-flows and room-to-room pressures, plus energy ratings on a number of homes.

T-Mass Wall

Okay, no one I've talked with locally has used this product yet, but it's worth a close look for high-efficiency homes.

Made by Dow Styrofoam, this technology places one layer of foam between two layers of concrete in either foundation or above-grade walls. In so doing, the inner layer of concrete acts as thermal storage material. When used for above-grade walls in Colorado's sunny climates, the T-Mass wall would significantly improve year-round comfort and reduce heating and cooling bills in a home properly oriented to the sun.

Walls built with today's typical insulated concrete forms (ICF) isolate the concrete from both the exterior and interior environments with a layer of foam. While ICF homes are very efficient, the concrete sandwiched between layers of foam can't absorb extra heat collected on a sunny winter day that can help offset heating bills at night. The T -Mass wall's innovative design, used for many years in Europe, beats this problem.

Steve Andrews consults with builders for E-Star Colorado and writes on energy issues (sbandrews@att.net). E-Star (www.e-star.com), is a nonprofit home energy rating system that works with both new and existing homes statewide.

2008 Built Green Colorado

Home Builders Association of Metro Denver, 9033 E. Easter Place, Suite 200, Centennial, CO 80112
(303) 778-1400 fax: (303) 733-9440  info@builtgreen.org

Last Updated: 10/05/2007