Alley 24

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Project Overview
  • Owner: Vulcan Real Estate; PEMCO Mutual Insurance Co.
  • Location: Seattle, WA
  • Building Type: Mixed Use-Office, Retail
  • Size: six-story building, 180,000 sf office, 23,000 sf retail
  • Completion Date: February 2006
  • Utilities: Seattle City Light (Electricity); Puget Sound Energy (Natural Gas)

Located in Seattle, Washington’s burgeoning South Lake Union neighborhood, Alley24 is one of the nation’s first LEED-certified mixed-use projects, offering a new model for sustainable, urban development. The urban infill project is sited on a full city-block within a 60-acre urban redevelopment effort, one of the largest in the US and anchored by three historic brick laundry buildings. The two-acre development integrates 180,000 SF of office space (six floors), 28,000 SF of retail shops and 172 residential apartments within the context of a highly sustainable, pedestrian-oriented development.

The commercial portion of the project, containing five stories of office over ground floor retail, is known as Alley24 East. Roughly three floors of the office space are occupied by NBBJ, the project architect. (Additional space is taken by Skanska USA the office building general contractor and a PR/Advertising agency.) As anchor tenant, NBBJ was faced with a challenge—balance their interest in innovation and experimentation in the performance of their own space, with the need for a resource-efficient building that would also meet the requirements of a multi-tenant, speculative office space. By all accounts, they met these goals by delivering a high performance building that integrates daylighting (88 percent of the building is daylit); a hybrid ventilation system with the ability to use building mass for night-time cooling (90 percent of the building can be ventilated or cooled with operable windows); and an underfloor air distribution system. Building tenants benefit from exceptional local control of lighting, operable windows and air conditioning. It is one of the first mixed-use developments to report the measurable occupant benefits of a sustainable building, with one tenant reporting a 30 percent decrease in sick days and another reporting a 10.3 percent increase in productivity per person.

As reported in an April 2008 Building Performance Review developed by the New Buildings Institute, the integrated strategies have resulted in a building Energy Use Index of 53 kBTU/sf-yr, a 43 percent reduction in energy use, as calculated by the ENERGY STAR Target Finder tool.

Building Energy Use Index (EUI)









Alley24 East has earned LEED Core and Shell Silver certification and both NBBJ and Skanska offices have been Certified Gold under the LEED Commercial Interiors rating system. In addition, Alley24 anchors the neighborhood’s pilot status within the LEED Neighborhood Development program. The National Association of Industrial & Office Properties (NAIOP) recognized Alley24 as both the 2006 Sustainable Development of the Year and the 2006 Mixed-Use Development of the Year. In 2009, Alley24 and NBBJ’s offices were honored with CoreNet’s Sustainable Leadership Awards for both interiors and architecture. As this article is being written, NBBJ’s office is currently under consideration for CoreNet’s top honor, the Global Innovation Award. 

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