Launch Slideshow

An array of 42 photovoltaic panels along the south-facing roof, hidden from street view, is set to gather and convert enough solar power into electricity to equally offset even the most extreme cooling loads and the rest of the homes power needs.

More Than Zero

More Than Zero

  • Project: Timbercreek Zero-Energy House, Lewisville, TexasSize: 2,538 square feetBuilt Cost: $155 per square foot (not including some sponsor donations and discounts)Completed: November 2009Certifications: LEED-Platinum; Energy Star Qualified Homes; Green Built Texas; ANSI (pending) HERS rating: 1Builder: GreenCraft Builders, LewisvilleArchitect and Interiors: William Peck and Associates, Lewisville

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    Project: Timbercreek Zero-Energy House, Lewisville, TexasSize: 2,538 square feetBuilt Cost: $155 per square foot (not including some sponsor donations and discounts)Completed: November 2009Certifications: LEED-Platinum; Energy Star Qualified Homes; Green Built Texas; ANSI (pending) HERS rating: 1Builder: GreenCraft Builders, LewisvilleArchitect and Interiors: William Peck and Associates, Lewisville

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    James Wilson

    PROJECT DETAILS
    Project: Timbercreek Zero-Energy House, Lewisville, Texas
    Size: 2,538 square feet
    Built Cost: $155 per square foot (not including some sponsor donations and discounts)
    Completed: November 2009
    Certifications: LEED-Platinum; Energy Star Qualified Homes; Green Built Texas; ANSI (pending)
    HERS rating: 1
    Builder: GreenCraft Builders, Lewisville
    Architect and Interiors: William Peck and Associates, Lewisville

  • Engineered decking from Trex is manufactured from recycled plastics and wood fibers to achieve a durable plank that does not require additional treatments to protect against the elements. The companys Accents series features a finished wood-grain on one side of the plank and a smooth finish on the other, enabling design flexibility; available profiles include straight and groove-edged, 1-inch-thick planks and nominal 2x6 planks. The saddle color specified is engineered to weather only slightly from its original hue. 800.289.8739. www.trex.com.

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    Engineered decking from Trex is manufactured from recycled plastics and wood fibers to achieve a durable plank that does not require additional treatments to protect against the elements. The companys Accents series features a finished wood-grain on one side of the plank and a smooth finish on the other, enabling design flexibility; available profiles include straight and groove-edged, 1-inch-thick planks and nominal 2x6 planks. The saddle color specified is engineered to weather only slightly from its original hue. 800.289.8739. www.trex.com.

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    James Wilson

    DECKING
    Engineered decking from Trex is manufactured from recycled plastics and wood fibers to achieve a durable plank that does not require additional treatments to protect against the elements. The company’s Accents series features a finished wood-grain on one side of the plank and a smooth finish on the other, enabling design flexibility; available profiles include straight and groove-edged, 1-inch-thick planks and nominal 2x6 planks. The saddle color specified is engineered to weather only slightly from its original hue. 800.289.8739. www.trex.com.

  • The home's back deck encircles an existing tree on the property, preserving the landscape while providing additional shade.

    http://www.ecobuildingpulse.com/Images/tmp99E%2Etmp_tcm131-303633.jpg

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    The home's back deck encircles an existing tree on the property, preserving the landscape while providing additional shade.

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    James Wilson

    The home's back deck encircles an existing tree on the property, preserving the landscape while providing additional shade.

  • The south-facing roof features an array of 42 215-watt photovoltaic panels from SunPower. Each panel features high-transmission tempered glass designed to achieve a DC electrical conversion efficiency of 17.3%. Also rated for impact and fire resistance, the 9.03-kW array is poised to generate 1,000 kWh of usable electricity, more than offsetting the homes projected demand. An in-home monitoring system is available. 800.786.7693. http://us.sunpowercorp.com.The standing-seam metal roof from Distinctive Roofing provides a durable surface against rain, winds, and heat while delivering a stable surface for the solar panels on the southern exposure. The non-combustible, 24-gauge, light-colored steel material also deflects UV solar radiation away from the attic to reduce cooling costs and contains at least 56% recycled content. It is Energy Starrated. 866.560.6679. www.distinctiveroofing.com.

    http://www.ecobuildingpulse.com/Images/tmp99F%2Etmp_tcm131-303640.jpg

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    The south-facing roof features an array of 42 215-watt photovoltaic panels from SunPower. Each panel features high-transmission tempered glass designed to achieve a DC electrical conversion efficiency of 17.3%. Also rated for impact and fire resistance, the 9.03-kW array is poised to generate 1,000 kWh of usable electricity, more than offsetting the homes projected demand. An in-home monitoring system is available. 800.786.7693. http://us.sunpowercorp.com.The standing-seam metal roof from Distinctive Roofing provides a durable surface against rain, winds, and heat while delivering a stable surface for the solar panels on the southern exposure. The non-combustible, 24-gauge, light-colored steel material also deflects UV solar radiation away from the attic to reduce cooling costs and contains at least 56% recycled content. It is Energy Starrated. 866.560.6679. www.distinctiveroofing.com.

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    James Wilson

    SOLAR PANELS The south-facing roof features an array of 42 215-watt photovoltaic panels from SunPower. Each panel features high-transmission tempered glass designed to achieve a DC electrical conversion efficiency of 17.3%. Also rated for impact and fire resistance, the 9.03-kW array is poised to generate 1,000 kWh of usable electricity, more than offsetting the home’s projected demand. An in-home monitoring system is available. 800.786.7693. http://us.sunpowercorp.com. ROOFING The standing-seam metal roof from Distinctive Roofing provides a durable surface against rain, winds, and heat while delivering a stable surface for the solar panels on the southern exposure. The non-combustible, 24-gauge, light-colored steel material also deflects UV solar radiation away from the attic to reduce cooling costs and contains at least 56% recycled content. It is Energy Star–rated. 866.560.6679. www.distinctiveroofing.com.

  • GreenCraft Builders took special care to ensure the Timbercreek zero-energy house fits in well with its existing neighborhood, including incorporating a design suited to the 1960s-era community and situating PV panels away from street view.

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    GreenCraft Builders took special care to ensure the Timbercreek zero-energy house fits in well with its existing neighborhood, including incorporating a design suited to the 1960s-era community and situating PV panels away from street view.

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    James Wilson

    GreenCraft Builders took special care to ensure the Timbercreek zero-energy house fits in well with its existing neighborhood, including incorporating a design suited to the 1960s-era community and situating PV panels away from street view.

  • The homes Energy Starrated cooling unit from AAON features a 3-ton, 100% digital scroll compressor that delivers only the cooling capacity required, saving energy. The unit is rated at 17-SEER, uses an R410A refrigerant, and is equipped with a dehumidifier to help maintain an optimum (50%) indoor relative humidity for occupant comfort and health. 903.236.4403. www.aaon.com.

    http://www.ecobuildingpulse.com/Images/tmp9A1%2Etmp_tcm131-303654.jpg

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    The homes Energy Starrated cooling unit from AAON features a 3-ton, 100% digital scroll compressor that delivers only the cooling capacity required, saving energy. The unit is rated at 17-SEER, uses an R410A refrigerant, and is equipped with a dehumidifier to help maintain an optimum (50%) indoor relative humidity for occupant comfort and health. 903.236.4403. www.aaon.com.

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    James Wilson

    HVAC
    The home’s Energy Star–rated cooling unit from AAON features a 3-ton, 100% digital scroll compressor that delivers only the cooling capacity required, saving energy. The unit is rated at 17-SEER, uses an R410A refrigerant, and is equipped with a dehumidifier to help maintain an optimum (50%) indoor relative humidity for occupant comfort and health. 903.236.4403. www.aaon.com.

  • Kohler supplied its standalone Escale bathtub; Purist sinks, faucets, and shower fittings; and Reve toilet to the master bathroom. The dual-flush (1.6-gpf/0.9-gpf), elongated toilet is WaterSense-labeled to reduce water use, as is the Purist wide-spread lav faucet, which includes a ceramic-disc valve for increased durability. The shower control features the companys Rite Temp pressure-balancing valve and high-temperature limit sensor to help reduce water use. 800.456.4537. www.kohler.com.

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    Kohler supplied its standalone Escale bathtub; Purist sinks, faucets, and shower fittings; and Reve toilet to the master bathroom. The dual-flush (1.6-gpf/0.9-gpf), elongated toilet is WaterSense-labeled to reduce water use, as is the Purist wide-spread lav faucet, which includes a ceramic-disc valve for increased durability. The shower control features the companys Rite Temp pressure-balancing valve and high-temperature limit sensor to help reduce water use. 800.456.4537. www.kohler.com.

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    Graham Hobart and GreenCraft Builders LLC

    BATH FIXTURES
    Kohler supplied its standalone Escale bathtub; Purist sinks, faucets, and shower fittings; and Reve toilet to the master bathroom. The dual-flush (1.6-gpf/0.9-gpf), elongated toilet is WaterSense-labeled to reduce water use, as is the Purist wide-spread lav faucet, which includes a ceramic-disc valve for increased durability. The shower control features the company’s Rite Temp pressure-balancing valve and high-temperature limit sensor to help reduce water use. 800.456.4537. www.kohler.com.

  • An array of 42 photovoltaic panels along the south-facing roof, hidden from street view, is set to gather and convert enough solar power into electricity to equally offset even the most extreme cooling loads and the rest of the homes power needs.

    http://www.ecobuildingpulse.com/Images/tmp9DA%2Etmp_tcm131-303848.jpg

    true

    An array of 42 photovoltaic panels along the south-facing roof, hidden from street view, is set to gather and convert enough solar power into electricity to equally offset even the most extreme cooling loads and the rest of the homes power needs.

    600

    James Wilson

    An array of 42 photovoltaic panels along the south-facing roof, hidden from street view, is set to gather and convert enough solar power into electricity to equally offset even the most extreme cooling loads and the rest of the home’s power needs.

  • Custom-fabricated sunshades mimic the standing-seam metal roof, providing shading as well as an architectural element.

    http://www.ecobuildingpulse.com/Images/tmp9DB%2Etmp_tcm131-303855.jpg

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    Custom-fabricated sunshades mimic the standing-seam metal roof, providing shading as well as an architectural element.

    600

    James Wilson

    Custom-fabricated sunshades mimic the standing-seam metal roof, providing shading as well as an architectural element.

  • The Energy Starapproved Sun Tunnel skylight from Velux reflects and projects daylight into the windowless utility room, mitigating the need for artificial lighting and therefore reducing lighting energy demand. Rigid and flexible tube models are available to accommodate various roof slope and framing situations, and the product is offered in 10- to 21-inch diameters. The tunnels also show no appreciable thermal gain or loss, according to the firm. 800.888.3589. www.veluxusa.com.

    http://www.ecobuildingpulse.com/Images/tmp9DC%2Etmp_tcm131-303862.jpg

    true

    The Energy Starapproved Sun Tunnel skylight from Velux reflects and projects daylight into the windowless utility room, mitigating the need for artificial lighting and therefore reducing lighting energy demand. Rigid and flexible tube models are available to accommodate various roof slope and framing situations, and the product is offered in 10- to 21-inch diameters. The tunnels also show no appreciable thermal gain or loss, according to the firm. 800.888.3589. www.veluxusa.com.

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    James Wilson

    TUBULAR SKYLIGHT
    The Energy Star–approved Sun Tunnel skylight from Velux reflects and projects daylight into the windowless utility room, mitigating the need for artificial lighting and therefore reducing lighting energy demand. Rigid and flexible tube models are available to accommodate various roof slope and framing situations, and the product is offered in 10- to 21-inch diameters. The tunnels also show no appreciable thermal gain or loss, according to the firm. 800.888.3589. www.veluxusa.com.

Even if net-zero hadn’t been the goal, Peck says he still would have oriented the house the same way, primarily along a north-south axis instead of the east-west exposure the previous homeowners endured. “We maintained the west-facing street presence of the original house (and its setbacks, per local ordinance—another reason the new house fits in so well), but the main living areas are oriented the opposite way,” he says, to achieve a more comfortable indoor environment.

To shield the new south-facing elevation, Peck designed deep roof overhangs, including a flat section extending from the gable roof eaves of the living room, and added an extensive deck with a trellised roof; the deck also corrals an existing mature tree on the property that provides another measure of shade. On the west side, Peck designed custom-fabricated sunshades for the bedroom windows that mimic the standing-seam metal roof and add to the dimension of that elevation.

High-performance, fiberglass-framed casement and awning-style clerestory windows help mitigate solar heat gain, as well, thanks to an NFRC-certified 0.23 solar heat gain coefficient; by design and placement, the windows also capture prevailing breezes and vent hot air for passive cooling. And, with a visual light transmittance of 52%, they allow ample natural light into and through the narrow building footprint.

“[Some people] give us a hard time about how many windows we use in an energy-efficient house,” says Peck, noting that the ratio in his designs is often about 20% of the total wall area, a third more than what’s considered conventional. “But if you have enough natural light, you don’t need to turn on the lights during the day and the spaces are more livable.”

With the comfort of his homeowners a priority, Miles recently committed to integrating finish products that reduce indoor pollutant sources. “When you build this tight, you have to consider your finishes,” he says, referring to their off-gassing of volatile organic compounds (VOCs). To that end, he specified and applied low-VOC paints and adhesives, and cabinets and other woodwork with formaldehyde-free MDF; he also completely eschewed finished flooring, instead gaining the owner’s support for a stained concrete floor throughout.

That floor combines with reclaimed brick from a south Dallas warehouse, engineered decking, fiber-cement siding, the metal roof, quartz surfacing, and stone accents for a relatively hassle-free maintenance list for the owners—and another aspect of the home’s overall sustainability. Even the PV panels, solar thermal collectors, and rainwater collection and irrigation system feature few moving parts, making them easier to troubleshoot, if necessary.

From the beginning of the project, Miles educated the owners about optimizing the efficiencies of their new home, including their selection of a television (plasma bad; LCD good), turning off lights in unoccupied rooms, and unplugging cable boxes and other devices at night.

The impact of a wasteful lifestyle on the energy bill is driven home, Miles says, when the owners watch the meters that Building America uses to track the consumption of the heating and cooling system and see that their behavior, not the A/C, is what’s boosting power demand. “Once they realize that, they start making some changes.”

Fortunately, the owners were savvy to Miles’ methods. “It all made sense to them from the beginning,” says Peck, who first worked with the owners to try and remodel the original house before finding extensive structural damage that required a teardown. “Their learning curve was very short.”

Rich Binsacca is a contributing editor for EcoHome.