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.

    http://www.ecobuildingpulse.com/Images/tmp99D%2Etmp_tcm131-309744.jpg

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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.

    http://www.ecobuildingpulse.com/Images/tmp9A0%2Etmp_tcm131-303647.jpg

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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.

    http://www.ecobuildingpulse.com/Images/tmp9A2%2Etmp_tcm131-303661.jpg

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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

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    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.

By today’s standards, it’s a modest house: three bedrooms, single level, architecturally suited to the late-1960s-era neighborhood in which it sits. Even after just a few months, and thanks in part to the preservation of the mature landscape around it, neighbors tend to forget what the previous house on the lot looked like—a sure sign that the new dwelling is fitting in just fine.

But unlike any other house in Lewisville, Texas, and only a few nationwide, this 2,500-square-foot home is designed and built to achieve net-zero energy consumption. 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, with a little extra capacity built in to earn some extra net-metering credits from the local utility. Ideally, the only line item on the homeowner’s monthly energy bill will be the service charge to keep the account open.

Still, the 600-square-foot PV array is only the mechanism for balancing the home’s power draw, not its defining feature. “This is a high-performance house with some green products in it,” says Chris Miles, a principal with GreenCraft Builders in Lewisville and a student of building science. “You don’t need green products for a house to perform well, but homeowners like it and I enjoy integrating them into the houses we build.”

That mix of passion and market savvy has enabled Miles to build seven homes to LEED-Gold or higher certification. This latest one reaches the Platinum level of that rating system (with a HERS score of 1, among other feats) and meets the standards for the Energy Star Qualified Homes and Green Built Texas programs (the latter of which is awarded automatically to homes that achieve at least LEED for Homes Silver); certification under the ANSI National Green Building Standard is pending.

Even after collecting all that hardware, the builder is only impressed with how his homes actually perform. That’s why, after discovering and diving head first into building science five years ago, Miles became a Building America builder, dedicated to reducing the carbon footprint of the built world under the guidelines of that Department of Energy program. “They come in and test for everything,” he says of the Building America verifiers who use homes like his to expand their database of real-world applications and results. “It’s the only way we really know how to improve what we do.”

That testing came in handy when Miles and architect Bill Peck considered the challenge of a net-zero house. “There’s no way of knowing if you have enough PVs unless you know how much energy the house will require,” a calculation based on its design, construction, and everyday occupant behavior, says Miles.

Results from monitoring the energy demand of a 2,400-square-foot, single-story, high-performance house Miles built two years ago, his first show home with GreenCraft, proved invaluable for this latest project, helping drive the home’s orientation and layout to accommodate an array that would generate 1,000 kWh of electricity to offset an anticipated draw of 805 kWh a year. “We didn’t have to guess on this one,” says the builder.