November 7, 2011
City tests new way to meet energy codes
The city of Seattle is testing a new performance-based energy code in South Lake Union, with the goal of helping developers of historic buildings meet rigorous energy efficiency goals in the most cost-efficient way.
The effort is a partnership between the city, Preservation Green Lab and Vulcan Real Estate. The performance-based code will be piloted with the Supply Laundry Building, a historic 30,000-square-foot structure.
Diane Sugimura, director of the Department of Planning and Development, said the move allows the city to preserve some of its history while meeting energy goals.
“In tough economic times, it is particularly important for the city of Seattle to look for ways to be flexible while still meeting energy efficiency objectives,” she said. “It’s a precedent that cities everywhere are paying close attention to.”
Seattle’s standard energy code is prescriptive, meaning it outlines specific requirements for everything from insulation to lighting. A performance or outcome-based code sets energy efficiency goals and leaves it up to the project team to decide how to meet them.
The deal laid out in a memorandum of agreement exempts the Supply Laundry Building from many prescriptive energy code requirements. The city will set energy efficiency targets. This will give the building owner, Vulcan, and its engineers greater flexibility in reaching those targets.
Prescriptive codes can discourage developers from renovating older, historic buildings because it is expensive to update each specific element to meet the code. The performance-based code allows the Supply Laundry design team to maximize features typical of older and historic buildings including natural lighting and ventilation through windows. The conventional energy code does not recognize energy savings achieved by passive features.
Liz Dunn, director of the Preservation Green Lab, a Seattle-based think tank focused on sustainability and historic preservation, said this project will protect the historic character of the Supply Laundry building while exceeding energy efficiency targets.
“Existing buildings present unique challenges and opportunities for energy-saving, and a one-size-fits-all code approach does not serve them well.”
The performance-based energy code also recognizes the impact of occupants on energy use, something that the conventional code and permitting process do not consider. The city will monitor Supply Laundry’s energy consumption for 18 months following occupancy, and will impose enforcement measures if needed to ensure the building meets the energy targets.