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This case study describes Imagine Homes, who met Builders Challenge criteria on more than 200 homes in San Antonio with rigid foam exterior sheathing, ducts and air handler in conditioned space in a spray-foam insulated attic, and high-efficiency HVAC, windows, and appliances.
Imagine Homes, working with the DOE's Building America research team member IBACOS, has developed a system that can be replicated by other contractors to build affordable, high-performance homes. Imagine Homes has used the system to produce more than 70 Builders Challenge-certified homes per year in San Antonio over the past five years.
Baldwin Homes of Arnold, Maryland, built a HERS 55 Builders Challenge-certified house as an “Eco-Model” home to showcase 69 green and energy-efficient features.
A Texas collaboration is working to streamline and enable an increase in photovoltaic capacity. The City of San Antonio has made tremendous progress in recent years in the area of solar energy installations on residences. These projects have been great successes, though not without the usual challenges associated with solar energy installations. The City has also seen an increased interest in solar energy systems in official “historic” neighborhoods. These installations have a potential for added challenges, as neighborhoods designated “historic” have additional restrictions, aside from standard building codes, about what changes and upgrades can be done to the exterior. This is in an effort to maintain the historic qualities of the homes and preserve the historical nature of the neighborhoods in which they are present. The purpose of this case study was to examine the construction of a new, single family home, with an included solar energy system, in an official historic neighborhood in San Antonio. Build San Antonio Green hoped to uncover what specific additional challenges the builder faced when working in a historic neighborhood and how those challenges were overcome, to serve as a model for other builders wishing to install solar energy systems in historic neighborhoods. This is of particular importance, as the City of San Antonio has more than 20 officially designated historic neighborhoods, and without proper knowledge of how to comply with the additional regulations, contractors, builders, and solar installers could potentially miss out on tremendous opportunities.
TO4 Task 3.1 - K Hovnanian Chicago, IL DOE Challenge Home Program Certified Home Constructed and Verified Specifications DOE Challenge Home Building envelope Ceiling R-49 blown fiberglass, Grade I Walls 2x4 framing @ 16 o.c. with R-13 fiberglass batts, Grade I and 1"" R-5 extruded polystyrene (XPS) insulating sheathing Frame Floors R-38 blown fiberglass, Grade I Basement Walls R-19 fiberglass batts draped full height, Grade I Basement Slab uninsulated Windows Above Grade: ENERGY STAR certified, U=0.29, SHGC=0.28 Basement: Non ENERGY STAR certified, U=0.29, SHGC=0.24 Infiltration 2 ACH 50 Mechanical systems Heat 95% AFUE sealed combustion natural gas furnace in conditioned space Goodman GMH950703BXAF Cooling 13 SEER split system Goodman GSX130301BC DHW AO Smith Vertex 100 0.96 EF natural gas tank water heater in 2nd floor utility closet Hot Water Distribution Redesigned trunk and branch Compliant with EPA WaterSense Efficient Distribution Requirements Ducts Located 100% in conditioned space via floor joists leak free to outside (5% or less) Ventilation Central Fan Integrated Supply (CFIS) ventilation with 6"" insulated outside air duct Fan Controller: Air Cycler FRV, with 6"" motorized damper 50 CFM outside air flow, 33% duty cycle (10 minutes on, 20 minutes off); ASHRAE 62.2-2010 compliance via an exhaust fan - Panasonic FV-08VQ5 WhisperCeiling Rerturn Pathways Active Return at Master Bedroom Transfer Grilles in Secondary Bedrooms Appliances, Lighting, MELs Lights 80% ENERGY STAR certified CFL Appliances ENERGY STAR certified refrigerator, dishwasher, and clothes washer; Natural gas range/oven and clothes dryer" STRUCTURE - Test House Lot 145 - 2013 DOE Challenge Test House Task 3.1 Bolingbrook, IL 60490 House is constructed and is DOE Challenge Verified by Don Nelson, a local rater. The purpose of this project was to evaluate integrated packages of advanced measures in individual test homes to assess their performance with respect to Building America Program goals, specifically compliance with the DOE Challenge Home Program. To that end, Building Science Corporation (BSC) consulted on the construction of five test houses by three cold climate production builders in three separate U.S. cities. (1) K. Hovnanian Homes, Chicago, Illinois (2) David Weekley Homes, Denver, Colorado (3) Transformations, Inc., Devens, Massachusetts. Overall, the builders have concluded that the energy related upgrades (either through the prescriptive or performance path) represent reasonable upgrades. The builders commented that while not every improvement in specification was cost effective (as in a reasonable payback period), many were improvements that could improve the marketability of the homes and serve to attract more energy efficiency discerning prospective homeowners. However, the builders did express reservations about the associated checklists and added certifications. An increase in administrative time was observed with all builders. The checklists and certifications also inherently increase cost due to: (1) Adding services to the scope of work for various trades, such as HERS Rater and heating, ventilation, and air conditioning contractor. (2) Increased material costs related to the checklists, especially the U.S. Environmental Protection Agency Indoor airPLUS and WaterSense Efficient Hot Water Distribution requirement. Ceiling - 18" cellulose Walls - 12" open cell spray foam in double stud walls Foundation - R-10 under slab, 3 1/2" closed-cell spray foam at walls Windows - Harvey U=0.20, SHGC=0.22 Infiltration - 1.0 sq in per 100 sq ft Heating - Mini split heat pump, 10.6 HSPF, 23 SEER Cooling - Mini split heat pump, 10.6 HSPF, 23 SEER DHW - 0.97 EF instantaneous propane water heater Ventilation - bathroom exhaust fans as basic option, HRV upgrade option Adams Circle Devens MA 01434 Cavite Street Devens, MA 01434
This Challenge Home case study describes the first certified DOE Challenge Home as constructed by e2 Homes. Completed in May 2012, the “Wilson Residence” in Winter Park, Florida, is a 4,305-ft2 custom home that scores a HERS 57 without solar and a better than zero net-energy HERS -7 with solar.
This case study describes a house that is designed to achieve an 87% reduction in source energy use when compared to the 2009 Building America Benchmark, and features high-R walls, roof, and foundation along with a high efficiency mechanical system.
G.W. Robinson of Gainesville, Florida, worked with Building America partners Florida Solar Energy Center and Florida HERO to achieve a true net zero energy home in 2010.
Located in the Lake Burden community in Windermere, FL, the KB Home GreenHouse is expected to produce as much energy as it consumes.
LifeStyle Homes of Melbourne, Florida, is aiming for affordable net zero energy homes with help from Building America research partner Florida Solar Energy Center.
Tommy Williams Homes of Gainesville, Florida, built two zero energy homes with help from DOE's Building America team members, the Florida Solar Energy Center and Florida HERO.
Building America worked with SMUD on this 1980s retrofit home to cut energy use by 104 points from a pre-retrofit California HERS score of 182 to a post retrofit score of 78.
Sacramento Municipal Utility District (SMUD) worked with DOE's Building America Program to cut energy use by more than 50% in a rehab of a 1950s tract home in Sacramento.
Clifton View Homes’s remodel of a 1962 rambler, on Whidbey Island in Washington State, cut energy costs by two-thirds.
Scott Homes worked with DOE Building America research partner Washington State University Extension Energy Program on a home in Olympia, WA, that achieved a HERS index score of 51.
Treasure Homes, Inc., achieved a HERS rating of 46 without PV on its prototype “Gem” home, located on the shores of Lake Michigan in northern Indiana, thanks in part to training received from a Building America partner, the National Association of Home Builders Research Center.
In October and November 2009, the TimberCreek Zero Energy House in Lewisville, Texas, opened as a Building America Demonstration House. The 2,538-foot,three-bedroom, 2½-bath custom-built home showed a home energy rating score (HERS) of 56 without the solar photovoltaics and a HERS score of 1 with PV.
The purpose of this project was to evaluate integrated packages of advanced measures in individual test homes to assess their performance with respect to Building America program goals, specifically compliance with the DOE Challenge Home Program. BSC consulted on the construction of five test houses by three cold climate production builders in three U.S. cities and worked with the builders to develop a design package tailored to the cost-related impacts for each builder. Also, BSC provided support through performance testing of the five test homes. Overall, the builders have concluded that the energy related upgrades (either through the prescriptive or performance path) represent reasonable upgrades. The builders commented that while not every improvement in specification was cost effective (as in a reasonable payback period), many were improvements that could improve the marketability of the homes and serve to attract more energy efficiency discerning prospective homeowners. However, the builders did express reservations on the associated checklists and added certifications. An increase in administrative time was observed with all builders. The checklists and certifications also inherently increase cost due to: adding services to the scope of work for various trades, such as HERS Rater, HVAC contractor; and increased material costs related to the checklists, especially the EPA Indoor airPLUS and EPA WaterSense® Efficient Hot Water Distribution requirement.