Image Credit: Bjorn Wallander Sunlight pours onto the polished concrete floor, bamboo stairs, and pure white walls from every angle.
Image Credit: Heather Ferrier Solar collectors send plenty of hot water to an 80 gallon storage tank. A reflective galvanized metal roof helps keep the house cool.
Image Credit: Heather Ferrier Image Credit: Bjorn Wallander Image Credit: Bjorn Wallander Structural insulated panels (SIP) make up the whole shell of this home. Strategically placed porches and light colored, durable materials all help to block the hot summer sun.
Image Credit: Toshi Woudenberg COMFORTABLE AT A REASONABLE COST: 51.4 MMBtu/year. Natural ventilation and daylighting help keep this contemporary home cool and bright at no extra cost. Passive solar heating keeps the place warm during most of the cooler months and a high efficiency air source heat pump picks up the slack on the hotttest and coldest days.
This striking contemporary home is a model of sustainability on a budget
This north-Texas contemporary home earned the third-ever LEED for Homes Platinum certification — but it could possibly share the award. The design of the LEED-H pilot home was inspired by architect Gary Olp’s own energy-efficient house. Heather Ferrier, general manager for Ferrier Custom Homes, fell in love with Gary’s place and enlisted him to rework the design into an affordable, comfortable, and sustainable home for her. Heather’s father Don, who also built Gary’s house, then set out to build his daughter’s dream home.
Plan on letting nature work for you
Gary and Don have been building sustainable homes for years, and understand that an integrated plan exploiting the skills and experience of a diverse team will give them the best house for the money. This included tapping into the resources of the Dept. of Energy’s Building America program and the expertise of consultants at Building Science Corp.
They worked together to adapt the basic concepts of Gary’s home into a more compact and affordable design. The home’s low energy demand relies on using as much of nature’s resources as possible. Tall open spaces create a chimney effect, drawing natural cooling breezes through thoughtfully placed windows. There is an air conditioner for hotter days, but its variable speed fan and automated controls help keep its power use well below average.
The abundance of windows and bright white walls let sunlight spread to every corner of the house. In winter, when the sun is low, it peeks under the home’s awnings and decks, shines directly on the concrete floors and warms the house. The sun also heats most of Heather’s hot water through solar panels on the roof.
Where you build affects what you build
The house sits on a south-facing urban infill lot. Ferrier Custom Homes spared every tree – including two large Indian Oaks. During the winter, when they shed their leaves, these trees allow sun in to assist with heating the home; in summer, they entirely shade the west facing windows. But overall the sunny site didn’t offer enough protection from the summer heat, so Gary penned several porches and overhangs into the design for some manmade shade.
The slope of the site and the metal roof set the stage for the installation of an underground rainwater collection system. The 3,000-gallon collection tank irrigates the garden and provides non-potable water to the house.
Materials make a difference
If you want to create a healthy and comfortable home while saving resources and energy, the materials you build with can be as important as how you build. In Heather’s home, structural insulated panels (SIPs) create an economical shell that helps keep the place comfortable year round. Reflective metal roofing tempers the hot Texas sun and should give many years of service before it could eventually be recycled. Stained and sealed concrete was used for the floor, not just for its low price and good looks, but also for its valuable thermal mass. All interior surfaces, including finishes, adhesives, flooring, laminate countertops, and even draperies were chosen because of their good scores on indoor air quality and sustainable manufacturing.
Good ideas can be contagious
There was enough talk about Heather’s home before construction even started to get it into the LEED for Homes pilot program and onto the U.S. Dept. of Energy’s Building America list of 2006 prototype homes. During and after completion it was featured in numerous news stories and was even open for public tours. Heather is no stranger to sustainable homebuilding, but reflecting on the overwhelmingly positive response, she mentioned that in her region “you don’t see that many projects like this.” With her inspiring example, hopefully that will soon change.
Use science and experience
Although Heather's home was inspired by Gary Olp's house, differing site conditions and materials required unique solutions. Because Heather's site is sunnier and her SIPs don't temper heat gains like the ICF walls in his house, Gary understood that sheltering overhangs and a lower proportion of windows would be necessary to keep Heather's home cool.
Energy modeling by Building Science Corp. helped pinpoint the right amount of glass (about 15% of total square feet) to fine-tune the home's energy efficiency. Jane Talkington at Oklahoma State University used a scale model to study seasonal sun exposure, influencing the placement of windows and awnings. The modeled performance of the initial design was 43% more efficient than the IECC Model Energy Code. Slight changes to the plans boosted projected efficiency by another 8%.
People have to know about green homes to like them
Some of the biggest surprises were in people's reactions to the project. After a show of interest from friends and colleagues, Ferrier Custom Homes decided to document the construction of Heather's home and work with a local newspaper to tell the story. Heather had not planned to use the house for public relations, but as curiosity about the project grew, she decided to open it for public tours. Early on, she hosted tours of 100 to 200 people, but on the last open day, about 5,000 visitors showed up to see the house.
People were apparently intrigued by the idea that a young single person on a tight budget could build a green home. The obvious focus on energy efficiency and the more recently popular concern for using local and renewable resources seemed to be the initial sources of public interest. "One of the first comments I heard from many of the visitors was ‘this house feels really happy'," Heather said. Perhaps the bright, airy spaces and warm, natural materials opened people's eyes to the fact that one of the most important qualities of a truly green home is comfort.
General Specs and Team
Builder: Ferrier Builders, Inc./Ferrier Custom Homes, LP
Architect/designer: Gary Olp, GGO Architects
Energy consultants: Building Science Corp.
Foundation: slab on grade
Walls: 4.5-in. SIP wall (R-24.3)
Windows: double-pane, low-e, gas-filled (SHGC .27, R-3.2)
Roof: 8.25-in. SIPs (R-33.5)
Garage: none (carport)
- Solar hot water collectors with 80-gallon indirect water heater (cost: $5,600)
- CFL lighting fixtures
- Energy Star ceiling fans and appliances
- Windows laid out for optimal daylighting
- Chimney effect of stairwell and window layout provides natural cooling, ventilation
- Attic fans
- Programmable thermostats
- Translucent roof in exterior storage areas for natural daylighting
Cooling: air-source heat pump (20 SEER, Daikin)
Water heating: (2) solar Collectors (Solargenix), 80-gal. hot water heater with internal heat exchanger and a supplemental 10-gallon drain-back tank (RHEEM Solaraide)
Annual energy use: 51.4 MMBtu
- 3,000-gal. rainwater catchment system for flushing toilets and irrigation
- Dual-flush toilets (1.6 GPF / 0.9 GPF)
- Low-flow faucets and showerheads (Delta)
- Xeriscaping with native plants
- High-efficiency washing machine & dishwasher (Kenmore)
Indoor Air Quality
- Gas burning, direct-vent, sealed-combustion fireplace
- Interior paints and sealers contain no or low VOCs
- ERV with HEPA filters
- Formaldehyde-free cabinetry
Green Materials and Resource Efficiency
- Fiber-cement siding, wood debris, and drywall scraps ground into mulch
- Fiber-cement and stucco siding
- Metal roofing and exterior trim
- Carpet contains 80% recycled-content P.E.T. fibers
- Regionally harvested white oak (a fastest-growing hardwood) for cabinetry
- Bamboo flooring at stairs & landing
- 100% pervious site outside home’s footprint
- Locally harvested stone from retaining walls & walking paths
- FLOR carpet tiles (biodegradable, made of recycled corn husks)
LEED for Homes points (earned/available): 90/108