Feature from Environmental Design & Construction

September/October 1999 Issue

Southern Sustainability

by Walter Brown & Dennis Creech, The Southface Energy Institute

Built to look like a house but designed to the standards of commercial buildings and training centers, the Southface Energy and Environmental Resource Center opened three years ago during the 1996 Summer Olympics in Atlanta, GA. Since its opening, more than 20,000 visitors have toured the 6,300-square-foot showcase of energy efficient and green building technologies, helping Southface to meet one of its primary missions: educating the public about sustainable building products and technologies. The design and construction was a joint effort between the U.S. Department of Energy, Oak Ridge National Laboratory, Lawrence Berkeley National Labs, and the Southface Energy Institute.

Southface functions as a multipurpose facility providing the southeast with a building science learning lab and training facility, a networking hub for the sustainable building industry, a clearinghouse for sustainable technology information, and a meeting facility for a wide variety of groups including architects, builders, utilities, environmental and community development organizations, and many other public and private sector agencies.

At least once a week various departments of DOE, EPA, and other federal and state agencies bring dignitaries and other visitors to Southface to be inspired by a tour or to hold regional meetings. Even a local neighborhood association calls Southface home for its monthly meetings.

What Makes Southface Different
While the Resource Center’s more than 100 sustainable technologies are awe-inspiring, most visitors are initially impressed by the beauty of the building, becoming aware of its energy and resource efficiency more slowly. The apparent normality of the building’s design, which looks like an upscale southern home with wrap-around porches and an airy feeling, is intended to keep the array of advanced technologies from feeling too cold and technical.

Opening the front door, visitors walk into a wide entryway surfaced in reclaimed pine flooring and pass into a great room flooded with daylight from south-facing low-E, gas-filled windows from Pella(R). Winter sunlight strikes a thermal mass floor in the passive solar sun space covered with tiles by Summitville(R) that are composed of 70% post-industrial waste from the feldspar mining industry. The great room is a central gathering spot also heated by a Heat-N-Glow(R) sealed combustion, direct vent gas fireplace.

The open floor plan of the ground level flows into the handicap-accessible kitchen and adjoining recycling area. From there visitors are taken into numerous meeting and office spaces that feature occupant-sensing lighting controls by Novitas(R), bathrooms with water-efficient dual-flush and pressure-assisted toilets from Kohler(R), and ultra quiet and efficient vent fans from Panasonic(R). Throughout the tour, wall space is used to provide additional learning opportunities with posters and displays explaining sustainable features and scores of fact sheets about products and technologies found at Southface.

Visitors have to be told that the space is also lit (on dark days) by naturally toned (high on Color Rendering Index scale) compact fluorescent and T-8 tube light fixtures powered by dimmable electronic ballasts. The Southface lighting design was created by Lawrence Berkeley Labs to be both beautiful and energy efficient. In fact, the photovoltaic roofing shingles by United Solar™, provide enough electricity to run most of the lighting package for the entire Center, or about 2,700 kWh per year.

Visitors are equally impressed with water conservation and water quality features built into the building and its grounds. Approximately 70% of the Center’s hot water needs are met with a rooftop solar water heater that is aided by ACT Metlund’s(R) D-Mand(R) hot water re-circulating pump that saves thousands of gallons of cold water at bathroom and kitchen fixtures. The Center’s washing machine is a horizontal axis model that saves approximately 30 gallons per load of laundry, and the dishwasher uses 25% less water and energy than typical models.

Porous pavement parking lots, a rooftop water harvesting system, and a combination of water-conserving plants and stormwater infiltration basins around the building are all part of an integrated approach to landscape water efficiency and stormwater management. A new bog and a planned constructed wetland feature will further handle both stormwater and graywater for even more wise use of water.

Numerous other sustainable features are visible around the building including recycled concrete rubble landscape walls and stepping stones, recycled plastic lumber decking by ChoiceDek™ by AERT, Inc. photovoltaic parking lot lights from Golden Genesis™, a solar-powered pond pump, electric car fueling stations, bicycle racks (and the disabled-accessible shower inside for sweaty riders), urban wildlife habitat and permaculture gardens, native landscape planting design, and the extensive tree-preserve areas. These sustainable features all create a powerful sense of what’s possible when a systems approach to building design is fully embraced.

Behind the Scenes Comfort and Efficiency
Not as visible on first blush are the scores of energy-efficient building products and mechanical systems that provide the high level of comfort taken for granted by most visitors to the Center. Starting at the basement level, Diamond Snap-Form™ insulating concrete forms (ICF) from AFM Corp. provide thermal mass plus R-16 comfort to the constantly used training center on the ground level. Six-inch-thick R-Control™ structural insulated panels (SIPs), also from AFM Corp., were used for all above-grade walls, creating an airtight R-25 wall system. The roof/ceiling combination, also built from SIPs, provides both R-30 insulation and an attractive vaulted ceiling above the third floor offices that allowed the design team to introduce additional light harvesting features including a light-collecting cupola.

Windows throughout the Center are R-2.96 and were strategically placed to maximize light-harvesting opportunities while minimizing heat loss/heat gain. Most windows are operable (casements and double-hungs) offering natural ventilation options during several months out of the year. Wide overhangs, shade screens, deep porches, and hardwood trees all work together to keep unwanted solar gain from overheating interior spaces.

As a result of the airtight (less than 0.15 natural air changes per hour) well insulated building envelope, the Center was able to significantly downsize its state-of-the art HVAC systems. The primary system is an Addison geothermal heat pump that uses water-filled pipes that extend down into eight 200-foot-deep wells. The geothermal system transfers heat to and from the earth rather than to the outside air. A natural-gas-powered heat pump provides efficient comfort to the first floor training facility.

Fresh air ventilation is provided by a Therma-Stor Ultra Aire APD dehumidification system. The unit brings in a variable volume of fresh outdoor air and mixes it with return air. This air stream is both dehumidified and filtered (95% atmospheric dust spot efficiency). In addition, other air handlers showcase pleated media filtration (85%) and a Honeywell electronic air cleaner (90%).

Considerable Energy Savings Proven
Appliances and computers throughout Southface are all Energy Star™ rated and further reduce the total energy load of the building. Billing data collected during the first several years of operation shows that Southface uses only 7 kwh per square foot per year compared to the national average of about 15.6 kwh for all commercial buildings — especially impressive since the Center is also open many evenings and every Saturday. A recent trial run at rating the building under the Energy Star Buildings Program (benchmarking tool available at http://io.aspensys.com/ epa_prod/startup/index.html) indicated that Southface scores at least a 90 — a performance which places it in the top 10% of all commercial buildings nationally.

Award-Winning Design Approach
An interdisciplinary charrette, involving federal agency contacts, representatives from national laboratories, architects, engineers, building scientists, and educators, was held to develop the design program, and to ensure that the design program integrated the educational goals of the organization.

The design program had four goals:

• energy efficiency and renewable energy technology
• environmentally sustainable building materials and techniques
• healthy building design
• accessible design for the physically disabled

A strength of the design program was its use of a “systems approach” to ensure integration of the sustainable design features and building products. The systems approach brought together all stakeholders — architect, mechanical engineer, landscape architect, interior designer, and over a dozen contractors — to discuss the design program goals, identify barriers to achieving goals, resources available to the project, and special design and construction considerations. This systems approach was essential, especially given that the project was constructed just before the 1996 Centennial Olympic Games — the busiest construction period in the history of Atlanta.

The design methodology called for a facility with three distinct functional areas to be integrated as one design:

• demonstration of a “model” home that showcases sustainable design features and products
• offices and work stations for the staff
• training rooms for professional seminars and consumer education programs

Measuring Success at Southface
Three benchmarks were set to measure success for this project:

• The amount of natural resources conserved
  The shell of the building reduced the amount of natural resources mined, harvested, or processed by over 25%. For example, insulated concrete forms replaced traditional formwork. The concrete had over 10% fly ash content, which increases strength while reducing the cement required. The structural insulated panels use approximately 25% less wood than framing with dimensional lumber and reduce energy use by about 20%. Wood scraps were chipped and used for mulch and other purposes.

• The quantity of atmospheric pollution prevented
  Although Southface was built to look like a residential building, it functions as a commercial facility, and the annual reduction in energy usage of approximately 61,000 kWh prevents more than 91,948 pounds in greenhouse gases every year. And, since the Center is used as a meeting place during the day, evenings, and on Saturdays, and as a workplace, actual energy and pollution savings over a comparable facility would exceed these estimates.

• The strength of educational programs
  The facility has been a powerful catalyst for sustainable design and construction worldwide. The Southface staff has been to several nations to speak on the project and frequently responds to international information requests. The project has won design awards from local and regional associations of the American Institute of Architects; American Society of Heating, Refrigeration, and Air Conditioning Engineers; American Concrete Institute; and the DOE/EPA Energy Star buildings program. The information gained from the project has also served as the foundation for “green” builder training programs for Habitat for Humanity International and the Greater Atlanta Home Builders Association. The U.S. DOE, EPA, and other organizations frequently cite the building as a model for private and public sector development.

Ongoing Southface Programs
While the number of visitors to the facility is impressive, thousands more learn of the products and technologies on display through the Southface web page www.southface.org and through features by broadcast and print media.

Southface has a strong education and technical assistance outreach program. In 1998, over 3,000 people across the nation attended workshops on topics ranging from commercial energy codes to making affordable housing sustainable. Through a partnership between Habitat for Humanity International, DOE, and Southface, over 500 local Habitat Affiliates have participated in a “Green Team” program designed to reduce the environmental impact of affordable housing.

Parts that Make the Whole at Southface
The following is a partial list of sustainable products, materials, and design elements featured at Southface:

• Energy Efficient Lighting - Warm fluorescent lighting is used throughout, including an overhead light shelf with T-8 lamps that scatters light across the ceiling. The lighting design reduces energy cost and the use of lighting by 50%.

• Daylight Harvesting - Well designed natural light matched to energy efficient lighting reduces energy required for lighting and cooling and increases worker productivity.

• High Performance Windows - Pella Designer Series Classic™ wood windows are argon filled, double-pane low-emissivity coated, insulated glass with a total window R-value of 2.96.

• Passive Solar Design - The major glass area faces south for maximum solar gain in winter. The south facing windows equal about 7% of the main floor area. A 2-foot overhang shades direct overhead summer sun yet allows the lower winter sun to enter the building. The winter sun warms the ceramic tile floor in the sunroom, great room, kitchen and laundry. The floor is covered with an earth-toned ceramic tile by Summitville Tile with greater than 70% post-industrial recycled materials over a 2.25-inch mortar bed providing 170 cubic feet of thermal mass.

• Energy Efficient Fireplace - Heat-n-Glo gas, direct vent fireplace with sealed combustion delivering 20,000 BTU’s of heat per hour with an Annual Fuel Utilization Efficiency (AFUE) exceeding 65%.

• Exterior Deck Flooring - Manufactured by ChoiceDek and made of 51% wood waste and 49% recycled plastic.

• Accessible Design - The house is designed to be fully accessible to people with physical limitations throughout the main and lower levels, including kitchen, baths, and hallways.

Healthy Home Design - Products to minimize or isolate interior pollutants include the following:

• Pristine(R) Escape™ by Benjamin Moore, 100% acrylic with zero volatile organic compounds.

• Natural fiber carpets by Shaw Industries made of wool with no petrochemical feedstocks.

• Airtight (less than 0.15 natural air changes per hour) and controlled ventilation to prevent outdoor pollutants, including radon, mold, pollen and dust, from entering the house. Controlled ventilation provides filtered fresh air in specific amounts at specific locations.

• Dehumidification system by Therma-stor Ultra-Aire APD dehumidifier provides fresh air ventilation, air filtration and high capacity humidity control.

• Radon mitigation system provided beneath the lower level concrete slab to collect and passively vent radon gases through plastic pipes to above the roof line.

• Carbon dioxide monitor on the lower level monitors air quality and operates fresh-air control.

Building Construction - the following is a partial list of sustainable building materials and methods.

• Insulated foundation and waterproofing system - The underground concrete foundation walls were integrally formed with 1-inch-thick Warm-n-Dri™ fiberglass sheathing (R-5) covering a Tuff-n-Dri™ polymer-modified asphalt emulsion waterproofing system.

• Structural insulated panel system – Above-grade walls and most roof areas were constructed of R-Control™ panels of expanded polystyrene core and OSB outer skins. They are twice as strong as conventional stud framing and use 30% less wood. The wall panels are R-24, and roof panels are R-30.

• Engineered wood products - Floor and structural framing uses laminated veneer lumber, and engineered floor joists are made from small diameter, fast-growing farmed trees, avoiding the use of mature trees or harvesting of old-growth forests.

• Airtight drywall and fiberglass batt insulation - The great room vaulted ceiling was sealed by stapling weather-stripping gaskets at key framing junctions, avoiding air leakage, often experienced at vaulted ceilings.

• Recycled wood flooring - The recycled heart pine floor, from Home Depot, provides strength and character as well as an environmentally responsible choice.

• Solar water heater - American Energy Technologies water heater, a 2- x 10-foot solar collector provides 20,000 BTU daily, producing an ample supply (70% of the Center’s needs) of 122-degree water.

• Solar electric shingles - Integrated photovoltaic shingles by United Solar resemble conventional roofing shingles (thin film amorphous silicon) and produce a peak power of 17 watts DC per 7-foot panel in full sun.
  

Mechanical Systems include the following state-of-the-art elements appropriate for Atlanta’s climate.

• Gas heat pump – A 3-ton York Triathlon™ natural gas heat pump provides heating and cooling for the ground floor. As it pumps heat, rather than burning fuel, the Triathlon has a 126% Annual Fuel Utilization Efficiency (AFUE) and a 15+ equivalent SEER rating.

• Geothermal heat pump - The upper two floors are heated and cooled by heat pumps that rely on eight, 200-foot-deep vertical wells, containing closed-loop plastic piping through which water is circulated.

• Energy management system - Honeywell Perfect Climate Comfort Center™ provides programmable controls for all the HVAC systems, electronic air cleaner, and humidity control.

Landscape Design provides for minimum maintenance and intrusiveness.

• Xeriscaping – drought-tolerant and indigenous plants save water and minimize maintenance.

• Water harvesting – a rooftop collection system stores rainwater in 55-gallon drums for watering during dry spells.

• Graywater irrigation - non-contaminated wastewater drains into a subterranean gravel bed in a planted terrace.

• Porous concrete - allows rainwater to percolate into the soil at the driveway and adjoining parking.

• Stormwater infiltration systems - swales and infiltration basins direct runoff into basins that allow water to percolate into the ground.
  
• Tree save areas - numerous large trees were carefully protected with drip line fencing, and roots were tunneled under rather than cut through for utilities (no trees planned for preservation have been lost after three years).

• Permaculture - numerous beds are planted in fruiting bushes and perennial herbs for use at the Center and by the public.

• Urban wildlife habitat - A U.S. Fish and Wildlife Service supported project that provides habitat and nesting sites for a variety of song birds and other wildlife. A posted walking tour is used for numerous scheduled and spontaneous tours.