The first city-wide collegiate team to be formed in Washington, D.C. and compete in the Solar Decathlon is Team Capitol DC, made up of students and faculty mentors from Catholic University, American University, and George Washington University. Their entry is HARVEST HOME, taking its name from its harvesting of natural resources, and is designed to meet the needs of a wounded veteran of the Iraq and Afghanistan wars who will live in the home after the competition.
One of the entries to this years Solar Decathlon competition is the so-called FluxHome project, envisioned and designed by a team of University of Southern California students. Their 1,000-square-foot solar-powered entry will be controlled by a single iPad. This ability to control all the complicated automation systems of this sustainable home offers the team an edge in the competition. FluxHome also uses the advantage of ample sunlight of the Southern California region to improve the indoor quality of life in this home.
Charles Pickering, the founder and CEO of architectural and engineering firm Pickering Associates, recently received a LEED-Platinum rating for his project at 12 Faith Meadows in Williamstown, WV. This is the first LEED Platinum certified home in West Virginia, and boasts of 11 kWDC of generation capacity. The solar system is located in an optimal array on the house and garage roof, and provides all the energy usage needs for the household, with some to sell back through the power grid. The house received a LEED Point Score of 113 and a HERS rating of .43.
In August 2013, Green Builder Magazine showcased the best durable/sustainable green building products that are made in the United States, pointing out that American manufacturing creates domestic jobs, reduces the impact of overseas shipping, and often makes use of locally-sourced raw materials.
Among the thirty-one products featured was the Xero Flor Green Roof System (the only green roof system to be included in the issue), which enables builders to create vegetative roofing on surfaces that range from 0 to 45 degree slopes. The Xero Flor system comprises a pre-vegetated mat, XeroTerr growing medium (a mix of compost and porous mineral aggregate), a retention fleece that distributes and stores water within the root zone, drain mat, and root barrier.
Washington-based builder Tanya Topolewski recently completed the rehab of a 90-year-old rowhouse in the Petworth neighborhood of Washington DC at 411 Varnum Street. The four bedroom and 3.5 bathroom rowhouse was rebuilt from the ground up with the aim of achieving net zero status. The builders are also seeking the LEED Platinum certification for the house.
The final design went through 15 alterations before the right mix of energy efficiency was settled upon. The east-west position of the house was a hindrance, but the roof was fitted with the maximum number of solar panels that it can hold, which are designed to provide the energy for the entire house. The solar panels were all installed at the maximum 25-degree tilt, since a greater angle would have been a wind hazard. On the final audit, the house received a 0 score on the HERS index. However, the auditor warned that whether the solar panels will produce sufficient energy to keep the house at net-zero will depend on the energy usage habits of the new owner.
All exterior walls of the house were insulated to between R25 to R35, which was achieved through the use of dense pack cellulose or dense pack cellulose and polyiso board. Since the HVAC systems design has a considerable impact on energy efficiency, the air handler was placed inside the building envelope. All except one duct are also placed inside the envelope. All of these ducts are in inside spaces, except for the lines in the attic and those lines are buried under a minimum of 10 inches of insulation.
To ensure maximum sealing, low expansion spray foam was used around the doors and windows, while regular expansion spray foam was used to seal the penetrations to the exterior, floor to floor penetrations, and behind band joists. In addition to that, caulk was used to further seal all the framing seams, cracks, joints, corners and sill plates. The drywall was glued to the studs and joists, while the exterior rigid board was overlapped and tape sealed.
The house was fitted with a 15 SEER/8.7 HSPF high efficiency heat pump system, making in 20% more efficient than the minimum required 13 SEER. Furthermore, the house’s HSPF is 8.7, which falls into most the efficient heat pumps range of between 8 to 10. The attic of the rowhouse if also insulated to minimum R60 with blow in cellulose at a depth of 16-20 inches.
The house was also fitted with Energy Star appliances and low-flow fixtures to maximize water efficiency. The windows and doors installed have ratings of SHGC .3 or better and U-factor .3 or better.
During the reconstruction, many items, such as door, window and base trim, interior doors and interior door hardware (handles, mortise locks, decorative plates, hinges and keys), vintage lighting, bath fixtures, framing lumber including studs, 2×6, 2×8, 2×10 and larger and hardwood flooring were removed, cleaned, stored and reused in the final construction.
The costs of the green elements of the house came to $50,000, which includes $25,000 for the solar panels, $10,000 for the energy recovery ventilator, heat pump, hot water heater, windows and insulation, and $15,000 to meet the requirements of the LEED Platinum certification. The house recently sold for $725,000 to Florence Petizon.
The Missouri University of Science and Technology entry in the U.S. Solar Decathlon 2013 competition, which takes place in Irvine, California on October 3-13, 2013, is Chameleon House, so named for its ability to adapt to the environment and transform according to the needs of its residents.