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Innovative Eco Office Earns LEED Platinum Certification

Aug. 25, 2009

The Eco Office, which serves as an office, demonstration, and training facility, has achieved LEED Platinum certification from the U.S. Green Building Council. It also qualifies for ENERGY STAR and EarthCraft Light Commercial certifications, and meets the 2030 Challenge launched by Architecture 2030.

“The Eco Office demonstrates that small commercial buildings can be green and achieve high performance standards at a reasonable cost. Our design and construction teams have exceeded our goals for the Eco Office, making it one of the greenest commercial buildings in the world,” Southface Executive Director Dennis Creech says. “We want everyone from the architectural, engineering, construction, and development communities to attend our workshops and training events so that they can see firsthand the myriad off-the-shelf and emerging technologies they can use to design and build high-performance facilities that reduce operating costs.

 “Furthermore, we’re continuously measuring the environmental performance of our building, which has been fully instrumented for this purpose, and we invite members of the worldwide research community to access our data, which we make available online,” Creech notes. “We want researchers to analyze it and use it to model enhancements to existing architectural designs and building techniques.”

As an example, Creech says that the Georgia Institute of Technology will model the performance of the building’s photovoltaic (PV) array system. He also noted that visitors from Canada, England, Germany, China, Japan, and other countries toured the building during construction and are eager to track building performance. “We’re confident that the Eco Office will continue to attract increasing worldwide attention for the research and educational opportunities we offer.”

Measuring Performance via the Building Dashboard

The Eco Office’s dashboard measures electricity consumption, daily kilowatt-hours of electricity produced onsite through the PV array, daily water consumption, daily gallons of water consumed and saved, and current rainwater levels in the building’s above- and below-ground cisterns. The dashboard also displays Atlanta’s current weather conditions and provides information on many of the building’s green features. On average, performance models project that the Eco Office will use 84-percent less potable water and 53.3-percent less energy than a comparable code-built building.

Creech explains that this performance puts the Eco Office among the top 9 percent of such U.S. buildings with regard to energy efficiency.

How Energy Efficiency was Achieved

Many strategies and products combined to achieve the Eco Office’s energy efficiency:

  • Site orientation, glazing allocation, and exterior shading controls that maximize daylighting while controlling unwanted solar heat gain.
  • High-performance thermal envelope, including insulated concrete form walls and low-E insulated glazing with thermally broken frames.
  • 6.4-kilowatt photovoltaic canopy, which supplied approximately 7 percent of the building’s annual energy needs over the past 12 months. The PV array was salvaged from a BP gas station that was being de-commissioned.
  • 1,937-square-foot extensive green roof, which reduces the urban heat island effect, stormwater runoff, and air-conditioning demands.
  • Dedicated Outdoor Air System (DOAS) with an evaporative cooler, energy recovery ventilator, and liquid desiccant system. The DOAS processes about 8 tons of cooling during peak summer conditions at roughly half the cost of conventional air conditioning.
  • High-performance lighting system, which includes high-efficiency lighting, dimmable ballasts, and light sensors that automatically adjust artificial lighting to complement natural light.

In addition, captured rainwater is used to save energy by cooling the air-source heat pump condensing units and solar electric system. Each kilowatt-hour of electricity saved saves approximately 1 gallon of water from being evaporated at a power plant.

Water-Efficiency Strategies and Products

Southface exceeded its original goal of 50-percent water efficiency beyond the LEED baseline, again by using a variety of complementary strategies and products that eliminate the use of potable water for sewage conveyance and irrigation, and save an estimated 61,000 gallons of potable water annually.

A stormwater management system is comprised of a 1,750-gallon cistern that collects rainwater from the PV canopy, and a 14,500-gallon underground cistern that collects storm water from the green roof and the overall Southface site. The collected non-potable water is then used for toilet flushing and minimal rooftop irrigation. If the larger cistern overflows, a weir diverts the stormwater to the municipal system. The roof’s drought-resistant sedum plants and native wildflowers manage stormwater runoff by filtering and diverting water to the underground cistern, and pervious paving throughout the Southface site also reduces stormwater runoff and groundwater recharge. The volume of water required for sewage conveyance is dramatically reduced through a combination of waterless urinals, dual-flush toilets that provide an option of using either 0.8 or 1.6 gallons per flush, and pressure-assist toilets that use only 1 gallon per flush. High-efficiency faucets with automatic solar-powered sensor controls use only a half-gallon of water per minute.

Educated Users are Part of the Efficiency Equation

“The super-efficient performance of the Eco Office, however, is not only due to its innovative green design strategies and products, but also to the Southface staff members who oversee the building’s systems on an ongoing basis,” Creech points out. “Educated users are an important part of the efficiency equation and make a major difference in any green building’s ongoing operational performance, helping building owners realize their return on investment.”

Donors Help Create a Virtual Noah’s Ark

Since part of the Eco Office mission is to educate the commercial architectural, engineering, construction, and development communities about sustainable building practices and products and technologies they can use in their next project, one of Southface’s goals was for the building to be a demonstration facility showcasing many different (but complementary) approaches to solving each functional and operational challenge. “As a result of generous donations to Southface from many manufacturers and service providers, the Eco Office is a virtual Noah’s Ark in that we have two different examples – and often more than two – of just about every building element, including multiple flooring materials, lighting technologies, toilets, roofing materials, and more,” Creech says.

Recycling and Salvaged Materials Help Southface Achieve More Goals

An example of cooperation among the contractors, as well as their sub-contractors, was the way in which they diverted some 98 percent of construction waste from the landfill. Metal, drywall, wood, plastic, and cardboard from the building site were all recycled.

A related goal was to use salvaged and high-content recycled materials as much as possible throughout construction. In addition to the PV roof canopy, other salvaged material includes oak window sills and benches, which were built from lumber from a demolished barn, and pedestrian bridge framing, which came from a nearby construction site.

Building materials with high recycled content include floor tiles made from recycled cork and rubber, roof garden walkway squares made from twice-recycled shredded rubber mats, cement countertops with high fly ash content, and roof decking that includes recycled wood flour.

The Eco Office Layout

The Eco Office is a 3-story structure with the “fourth floor” being The Turner Foundation Green Roof. Situated to the east of Southface’s Resource Center, which is a residential green building that was constructed in 1996, the two facilities are now joined by the Eco Office’s 3-story Melaver Atrium.

The first floor includes The Home Depot Foundation Training Center, bathrooms, and a lobby area; the second floor includes the Kendeda Board Room and mechanical room; and the third floor includes the Epic Metals Conference Room, an office area, a break room, and staff bathrooms.

“At 10,100 square feet, our building isn’t huge but rather in the same size range – under 10,000 feet – as about 74 percent of commercial buildings in the United States. For that reason, and because the Eco Office is constructed primarily with off-the-shelf technologies, it should serve as an inspiration to the architecture, engineering, construction, and development world by demonstrating that green building design and construction, even for smaller facilities, can be cost effective,” Creech says.

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