Timbercreek net-zero home goes well beyond energy savings
When Bill Peck got involved with designing the Timbercreek Net Zero Energy House in Lewisville, Tex., the decision was quickly made to achieve LEED accreditation from the U.S. Green Building Council.
However, that proved to be only the beginning of the sustainability efforts for the 2,500 square foot dwelling -- which was built on the site of a former home that could not be renovated because of a severely damaged foundation.
Energy efficiency is clearly the highlight of the home – the 42 solar panels should deliver enough energy each year to zero out utility payments for its owners. In fact, since the home opened in January, it is on track to put more juice back on the grid than it uses.
“This is a true net-zero home, which means it is tied to the grid and designed so that by the end of the year, energy use balances out to zero,” says Peck. “From January through [June], the solar panels have produced more energy than the house used. Considering that takes into account usage in January and February during the winter months, we’re ahead of the game as we go into the summer.”
The home was re-designed into an L-shape and turned from its original east-west orientation to sit with a south-facing roofline to utilize the long exposure to the sun that powers the solar panels. They produce about 1,000 kilowatt-hours of energy each month.
“Knowing that we wanted to go to zero-energy house from the beginning, we started by investigating which solar array we’d need and how many square feet it would require so we’d know how much roof to allow for that,” says Peck. “ We looked at the optimal solar angle so we could get the most energy out of the solar panels.”
Features of the home
However, Peck, the principal at William Peck & Associates Architects, and GreenCraft Builders LLC of Dallas, didn’t stop there. They incorporated a host of cool and innovative ideas into designing one of the most sustainable homes in the country.
For example, sustainable products were used whenever possible. To hold the lattice in place around the deck area in the rear of the house, the builders used discarded drill stems from oil rigs for columns. The 3-inch pipes, which were painted when installed, were previously used to drill oil wells into the core of the earth, so their strength and longevity are major plusses for home building applications. Such equipment is plentiful in Texas, especially since drill stems can only be used so many times in drilling applications. In addition, the deck was built with Trex decking made from recycled sources.
With exception of the cedar lattice work, no wood was used on the exterior of the house, to resist rotting and limit maintenance. Part of the sustainability goal for the home was to use materials that were not only green, but also require little to no maintenance. Much of the house is constructed from stone, reclaimed brick (painted), and Hardie board siding, which is made primarily of concrete and is termite and moisture resistant. The home utilized larger timbers of cedar to help improve longevity, since thinner cedar has a shorter lifespan.
When building a house as tight as the Timbercreek home, indoor air quality becomes extremely important. Therefore, builders used VOC–free paints and stains. “We did things that normal builders don’t even think about to make sure there was no off-gassing from anything,” says Peck. The cabinetry and trim work in the house came from special sources and were certified to be formaldehyde-free.
The house also stayed away from wall-to-wall carpeting, opting for stained concrete in many areas. The interior solid doors from Masonite feature compressed reclaimed straw as door filling. The doors provide a nice sound balance for the home.
“We built a very tight and quiet house, and with all the hard surfaces, you need to be aware of sound quality issues,” says Peck. “Instead of hearing the lawn mower outside, people can hear their spouse breathe in the next room. We pay attention to room-to-room sound transfer.”
The house also used a 5,000-gallon rainwater collection system for outdoor irrigation.