Dec 5 2007
Responsible for nearly half the world's greenhouse gas emissions -- 20 percent more than transportation -- the building industry is the primary contributor to global warming. To address this issue, the national design community has called for an immediate 50 percent energy reduction in all new buildings -- and the call-to-action is working. A recent success story is Alley24, a new mixed-use building in Seattle that in little more than one year of occupancy reduced the office building's CO2 emissions within a few percentage points of the 50 percent target (results are based on current energy use information from the U.S. Department of Energy (DOE) ENERGY STAR Program).
"Alley24 is the first project in the city to demonstrate that building energy efficiency targets set out by the 2030 Challenge are achievable today," said Diane Sugimura, Director of Seattle's Department of Planning and Development. "It shows Seattle can take positive climate action now and that it's possible to turn back the CO2 clock-one building at a time."
Seattle City Light has also reviewed Alley24's energy consumption history and Robert Balzar, Director of the Seattle City Light Conservation Resources Division stated, "The project is on the verge of meeting the immediate 50 percent energy reduction goal, if not already exceeding it. We applaud those who made this project possible."
Co-owned by Vulcan Real Estate and PEMCO Insurance, Alley24 opened in 2006 and houses the Seattle offices for three international firms: NBBJ, a leading architecture and design firm that also designed the project; Skanska USA Building Inc., an international construction group that served as general contractor for the project; and the international marketing and communications group WPP. The office building was awarded LEED(R) (Leadership in Energy and Environmental Design) Silver for its core and shell from the U.S. Green Building Council (USGBC), and both Skanska's and NBBJ's offices recently received LEED Gold certification for their commercial interiors. LEED certification is the nationally accepted benchmark for the design, construction, and operation of high-performance "green" buildings. In order to achieve LEED Gold certification, the offices had to demonstrate high performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.
As one of the nation's first LEED-certified mixed-use projects, Alley24 creates a new model for sustainable, mixed-use urban development. Located in Seattle's developing South Lake Union neighborhood -- which is currently undergoing one of the U.S.'s largest urban redevelopment efforts -- the project is sited on a full city block and anchored by three historic brick laundry buildings. The development integrates 185,000 SF of office space, 28,000 SF of retail shops, and 172 residential apartments to create a sustainable live/work/play environment.
To achieve the high-level of energy reduction, NBBJ -- working with engineering firms Flack + Kurtz and McKinstry -- incorporated energy saving techniques such as motorized sunscreens that track the sun's rays, automatic reflector blinds and low energy fixtures. One of the most innovative solutions is the hybrid HVAC system that includes both operable windows for natural ventilation and a raised floor system that can selectively deliver heated or cooled air. With the raised floor design, conditioned air is delivered beneath the occupant's feet for better air quality, comfort, and personal control -- providing several hundred more hours of "free cooling" than overhead air conditioning. In addition, each floor has operable windows and the ability for fan-assisted natural ventilation that allows building occupants the option of eliminating air conditioning altogether.
Alley24's energy reduction achievements are helping position the entire neighborhood for LEED Neighborhood Development designation -- a new pilot program from the USGBC that will certify whole neighborhoods as sustainable. NBBJ is part of the South Lake Union leadership team heading up this new program and initial assessments are looking good for the area.