MAY/JUNE 2008: EXTENDED ONLINE VERSION

CASE HISTORY:
A Solar Community Rises in the South

After nearly four decades, Stitt’s mission to build super-efficient homes is achieved at his sustainable development in Arkansas.

By Orlo Stitt

Stitt house

Built in 2006, David and Karen Stitt’s award-winning home sits on a 1.96-acre site with a steep eastern slope. Following South Sun Estates on the Lake’s covenants, the home was oriented for maximum passive solar gain and minimal site disruption. Photo courtesy of Stitt Energy Systems Inc.
In 1973, the passive solar home that my wife, Mary, and I built in Village du Soleil in Canada was featured on prime-time television in the United States and Canada as an example of energy efficiency. The Arab oil embargo was in place, and we were convinced that everyone would soon be demanding energy-efficient homes. We were wrong — but we didn’t know it then.

The oil embargo heightened my interest in energy conservation, and my own home proved that efficient design and building techniques could deliver cost-effective benefits even through brutal winters and hot, humid summers. I knew then that I wanted to build sustainable homes for a living. So in 1978, Mary and I, with our then two children, returned to the States to launch Stitt Energy Systems Inc.

We located in Northwest Arkansas and began planning our next energy-efficient, sustainable development. We built a passive solar model home to let people see and feel what this concept was about. But limited public awareness meant we would need a strong incentive of some kind to motivate people to buy these homes. We found the incentive in a beautiful 38-acre (15.4-hectare) parcel of property on the shores of Beaver Lake. It became our new subdivision and was named South Sun Estates on the Lake.

Driving Demand for Low-Energy Homes
Beaver Lake seemed to be a nearly perfect incentive for South Sun Estates. Located high in the Ozark Mountains, the 28,370-acre (11,480-hectare) lake is surrounded by 487 miles (780 kilometers) of shoreline, with towering limestone bluffs, natural caves and a mix of deciduous and evergreen trees. With four distinct seasons, the scenery is nothing short of spectacular.
Stitt House Highlights
Northwest Arkansas

• 3,700-square-foot (344-square-meter) home named NAHB’s “Model Green Home Building Guidelines Home” of 2007.
• Occupied by David and Karen Stitt’s family of four.
• Passive solar orientation and design.
• Energy-recovery ventilator exchanges air at 119 cubic feet (3.4 cubic meters) per minute.
SEER 16-rated heat pump and high-efficiency wood-burning fireplace supplement passive solar heating.
• Water heated by a closed-loop solar thermal system.
• Water-conserving fixtures and landscaping.
• Construction completed in 2006. Valued at $500,000.
We divided the property into 29 approximately 1-acre (0.4-hectare) plots and drafted covenants requiring that every home achieve certain levels of energy and resource efficiency. The covenants stipulated that 50 percent of the glass in each home face solar south and that domestic water be heated by solar, on-demand gas or geothermal resources. The covenants also included guidelines addressing drainage, site disturbance, home orientation and landscaping. All 29 lots were plotted to provide good southern exposures. A common property and paved pathway for golf carts and ATVs allow all homeowners access to the community boat dock and swim platform.

Over the years, I’ve found that energy-efficient custom home building depends as much on public awareness and consumer confidence and commitment as it does on incentives and the economy. While many of us expected a boom in solar applications after the early ’70s, it just didn’t happen in Arkansas, and that’s reflected at South Sun Estates. Although homeowners in recent years have been able to take advantage of the 30 percent federal tax credit (up to $2,000) for solar water-heating and photovoltaic systems, Arkansas offers no lucrative state or utility incentives for renewable energy. As of 2007, approximately 30 percent of the lots in South Sun had been sold and built on, and most homes had solar water-heating systems. One house — Mary’s and mine — has a photovoltaic system. The housing-market slowdown plus few, if any, energy incentives could be distressing for prospective buyers, but it is not for me.

While South Sun Estates has been developing, Stitt Energy has designed and built more than 300 energy-efficient, passive solar homes in 16 states. The homes have consistently earned a Home Energy Rating System (HERS) rating of between 38 and 65 and “Five Stars-Plus” status (85 is the maximum HERS rating allowed for Energy Star status, and a rating of less than 71 earns Five Stars-Plus). We won the prestigious People’s Choice Award in 2006 and 2008, were named Builder of the Year in 1999, and won 18 EnergyValue Housing (EVH) Awards from the National Association of Home Builders (NAHB) Research Center.  
Stitt Home Energy Performance
• Pollution avoided in pounds per year, as compared to a reference home used by RESNET, the Residential Energy Services Network:
  Carbon Dioxide: 18,546
  Sulfur Dioxide: 54.8
  Nitrogen Oxides: 40.4

• Annual energy end-use in million Btu per year, as calculated by a certified third-party energy rater:
  Heating: 17.7
  Cooling: 5.4
  Water Heating: 2.6
  Lights and Appliances: 36.4

• Average monthly electric bill: $76.75
Three of our EVH Award winners are located in South Sun Estates, and last year, a fourth home in the development won a national award. For me, it was probably our most significant award to date. This “Model Green Home Building Guidelines Home of the Year” belongs to our son and daughter-in-law, David and Karen Stitt, and their two children. This NAHB award brings together everything we have been communicating to customers and the building industry for more than 30 years.

Demonstrating the Promise
David and Karen’s Craftsman-style home earned 503 points in the NAHB Green Home Building Contest, when only 395 points were required to achieve “gold” performance. It also earned a HERS score of 54 (a Five Stars-Plus rating). That makes it 46 points better than required by the IECC Code and 31 points more efficient than required for Energy Star status. And the house achieved its efficiency without compromising style, comfort or convenience. Built in 2006, David and Karen’s home sits on a 1.96-acre site with a steep eastern slope. The contour of the land lent itself naturally to a lower-level garage/shop with minimal excavation into the hill. Following covenant guidelines, the home was oriented for maximum passive solar gain and minimal site disruption. To ensure a tight thermal envelope for the home, the slab foundation and stem and basement walls were constructed of insulated concrete forms.

The home’s aboveground walls were constructed of 2x4 wood studs and insulated with open-cell soybean-based spray foam, plus a continuous layer of foam to reduce structural heat bridging. Using spray foam insulation this way provides the walls with an R-value of 23 plus excellent air sealing. The walls were wrapped with Tyvek, over which builders installed fiber cement siding and recycled brick.

With summer temperatures often soaring above 100ºF (38ºC) in Arkansas, David and Karen included a radiant barrier in the roof. Testing by Oak Ridge National Laboratories has shown that in attics with R-19 insulation, radiant barriers can reduce summer ceiling heat gains by up to 42 percent compared to an attic with the same insulation level and no radiant barrier. David and Karen used approximately 7.5 inches (19 centimeters) of soybean-based foam insulation in the ceiling, providing an insulation value of R-30 and, with the radiant barrier, reduced their cooling load substantially.

Best Practices for Low-Energy Building
• Minimize disturbance of the building site and save as many trees as possible.
• Site each home for maximum use of solar energy (passive and active).
• Design eaves and overhangs to admit winter sun and block summer sun.
• Create a tight thermal envelope using air sealing, vapor barriers and insulation.
• Choose low-E, argon gas-filled windows with wood or vinyl framing, and use operable windows and skylights for flow-through ventilation.
• Install insulated window coverings.
• Use a radiant barrier in the roof.
• Install a solar water-heating system.
• Select energy-efficient, healthy HVAC systems.
• Choose energy-efficient and water-conserving appliances and fixtures.
• Landscape for water conservation and erosion control.
• Use compact florescent or LED lighting instead of incandescent.
• Use photovoltaic, wind or micro-hydro systems as a source of electricity.
To maintain healthy indoor air quality, David and Karen installed a Venmar Duo 1.9 energy-recovery ventilator (venmar.ca, $2,000). This duct-connected unit transfers heat and moisture from the outgoing air to the incoming air during the heating season and transfers heat and water vapor from the incoming air to the outgoing air during the air-conditioning season at the rate of 119 cubic feet (3.4 cubic meters) per minute.

The home’s south-facing glass is protected by eaves and overhangs with widths calculated for the home’s 36º latitude. They provide shade in the summer when the sun is high in the sky (about 77º at noon on June 21) and allow sunlight to enter the house during winter when the sun is lower on the horizon (about 31º at noon on Dec. 21). Deciduous trees preserved from the original landscape also shade the south windows during the summer and, after dropping their leaves in the fall, allow sunlight into the bedrooms and living areas during the winter. In addition to admitting heat, the windows provide daylighting in the main living areas and open to a magnificent view of Beaver Lake. All window glass is double-paned, low-E and argon-filled (Chelsea brand windows manufactured by H.G. Barr, weatherbarr.com).

To supplement passive solar heating in the home, the couple installed a SEER 16-rated two-speed heat pump, the Carrier Infinity (residential.carrier.com, $10,842, including duct work and installation). They also installed a highly efficient wood-burning fireplace, the Sequoia Large from Vermont Castings, with an outside combustion air source (vermontcastings.com, $3,500 including flue). A combustion catalyst increases burning efficiency, giving the fireplace an EPA efficiency rating of 73 percent. The fireplace, which functions like a wood stove, can heat their 3,700-square-foot (344-square-meter) home during almost any winter day in Northwest Arkansas. Trees removed from the home’s footprint prior to construction were cut and stored for firewood.

For solar water heating, David and Karen chose a closed-loop Supplenergy, SESI-80-40 system (developed by Stitt Energy Systems and SRCC-rated), because temperatures routinely fall below freezing during Ozark winters. Antifreeze, which serves as heat-exchange fluid, flows through a 4-by-10-foot flat-plate solar collector positioned to the south on the roof. The antifreeze transfers solar heat to a heat exchanger, which is wrapped around an 80-gallon (300-liter) water-storage tank inside the house. To power the fluid-circulation pump, installers mounted a 10-watt photovoltaic panel next to the rooftop collector panel. A timer allows the family to turn the backup electric element on or off depending on system use, the weather and time of year. For fast hot-water delivery, the designer located the water heater within 30 feet (9 meters) of the laundry and two bathrooms on the home’s second floor and 24 feet (7 meters) from the kitchen on the first floor. The solar water-heating system qualified for the 30 percent federal tax credit, reducing its final installed cost to $4,600.
Building Community at Sustainable Developments
Even as public appreciation for low-energy living increases, developers of sustainable communities can face conflicts among property owners whose commitment levels differ. I’ve learned that by establishing some parameters from the start, we can minimize those differences and encourage compromise. I offer some advice based on my experience at South Sun Estates on the Lake in Arkansas:

• Plan to design, specify and build — or commission approved contractors to build — all of the homes in the development, rather than allowing owner-builders.

• Be sure development covenants clearly specify homeowner benefits and responsibilities. Include remedies and penalties for violating the provisions, and obtain written confirmation that each property owner/buyer has received a copy of the covenants.

• Rigorously plan and administer the property owners’ association and the architectural control committee proceedings and meetings, and file accurate minutes of those meetings.

• To ensure impartiality, developers that live within their own developments should be prepared to objectively administer and enforce the covenants.
Because Beaver Lake supplies water to the rapidly growing population of Northwest Arkansas, residents at South Sun Estates are mindful of both usage and runoff. David and Karen installed low-flow faucets and showerheads, along with toilets that use 1.28 gallons (4.8 liters) per flush. They also used water-conserving landscape design. A small area of drought-resistant zoysia grass provides a place for the children to play and a smooth transition to the wooded area beyond. Other areas of the yard were left natural or covered with mulch made from brush cleared from the site. Much of the waste on the site was recycled; none of it was buried or burned.

Other than propane used for cooking and drying clothes, the home is all-electric and all appliances are Energy Star-rated. Because of the couple’s holistically green home design, the solar water-heating system, their energy-conscious lifestyle and the conservation measures built into their home, David and Karen’s average monthly utility bills, including electricity and propane gas, have averaged $76.75 during the past year.

Continuing the Mission
The mission of Stitt Energy Systems Inc. remains the same today as when I began the company: “To provide energy-efficient homes that are environmentally responsible for the satisfaction, health, welfare and happiness of our customers, our employees, our investors and future generations.” Now I might add “with or without government or utility incentives.” As we celebrate our 30th year in business in Arkansas, my dream and mission is becoming a reality.

South Sun Estates is evolving nicely, and I continue to believe that progress in sustainability and energy-efficient living depends on the commitment of educated consumers and federal policy makers. To meet that challenge, we continue to present seminars and participate in home shows and energy fairs whenever possible.

I may have been wrong about consumers demanding energy efficiency in the ’70s, but attitudes and lifestyles appear to be changing. I’m becoming “more right” with every month that passes.

About the author: Orlo Stitt is founder and president of Stitt Energy Systems Inc. He is a certified home energy rater and a member of the American Solar Energy Society, U.S. Green Building Council, Energy and Environmental Building Association and NAHB. He and his wife, Mary, live in a near-zero-energy home in South Sun Estates. They generate power and net meter using a 3-kilowatt photovoltaic array on their home. Both Orlo and Mary drive hybrid cars. Contact Stitt at orlos@stittenergy.com.
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