Local Sustainability - World Stage

The David L. Lawrence Convention Center: Site of the 2009 G20 Summit

Pittsburgh, Pennsylvania hosted the G-20 Summit on September 24-25, 2009. President Obama chaired this meeting of leaders from countries around the world that represent 85 percent of the world’s economy. The meeting took place at the David L. Lawrence Convention Center, the first and largest Gold LEED® (Leadership in Energy and Environmental Design) certified convention center in the world, and a testament to Pittsburgh’s sustainable focus. Rafael Viñoly’s innovative design and Burt Hill’s “green” engineering solutions combine to create a facility that celebrates energy-conscious design and fiscal responsibility.

The convention center is located on a remediated brownfield site with a strong connection to the Allegheny River. The facility cantilevers over the river, echoing the form of nearby suspension bridges. The tensile structure, with its vast expanses of glass, affords views up and down the river and allows deep daylighting in the main exhibit halls. As a testament to the economic revitalization of downtown Pittsburgh, this civic community building includes four levels of exhibit halls, meeting spaces, ballrooms, and administrative offices; and is strategically sited with close proximity to public transportation.

Three sustainable strategies in particular were employed to design a facility that is environmentally friendly, profitable to operate, and that provides healthy environments for users.

Natural Ventilation

With the incorporation of natural ventilation into the design, the facility relies less on the heating, ventilation, and air conditioning systems to provide occupant comfort, thus consuming less water and energy. To create natural cross ventilation, the convention center takes advantage of the chimney effect created by the sweeping roof and of convection currents from the Allegheny River flowing next to the building. Vents in the north and south facades allow outside air to flow through the building without using fans or other mechanical systems. This provides efficient air circulation when outdoor temperatures are between 45 and 65 degrees Fahrenheit, which is about one-third of the year in Pittsburgh. A weather station near the roof measures air temperature, humidity, and wind speed and direction. When conditions are right, the 20 air-handling units serving the exhibit halls shut off, the vents open, and outside air flows into the exhibit area.

The convention center also uses natural ventilation to flush air from the exhibit halls at night during warmer periods, which further reduces cooling system operating time.

Natural ventilation saves 3.8 million kWh of energy per year.

Natural Lighting

Clerestory windows located where the walls and roof meet and long, six-foot-wide ribbon skylights covering ten percent of the roof area provide natural daylight for 75 percent of the exhibition space and save 9.5 million kWh of energy per year. Aside from the aesthetic appeal of natural light, natural daylight can boost business too. A study for the Pacific Gas and Electric Company suggested that using daylighting in trade or commercial exhibits could increase sales on a convention floor by nearly 40 percent.

Water Efficiency

The convention center taps Pittsburgh’s “fourth river,” the aquifer that runs beneath downtown, to provide makeup water for the refrigeration system cooling towers, reducing the demand for water from the city water system. Pulsed-power treatment of the cooling tower water to eliminate bacteria without chemicals further reduces the demand for city water. This design element saves an estimated 1.8 million gallons of water annually.

The convention center uses recycled water for toilet and urinal flushing. The water is conditioned by an aerobic digestion and sub-micron filtration system. The effluent is totally colorless and odorless. With final ultraviolet light treatment, the effluent has been treated for everything but viruses. The system recycles 50 percent of the center’s water and saves an estimated 6.4 million gallons annually.

The David L. Lawrence Convention Center is not only an architectural landmark of international significance, but it is also an important milestone in Pittsburgh’s commitment to a sustainable, clean environment. By employing sustainable design strategies, total energy consumption was reduced by 30 percent compared to that of similar, but more conventionally engineered facilities. The total energy saved is equal to the electricity consumed annually by 1,900 Pittsburgh households, and the water saved is enough to supply 132 Pittsburgh households for a year.