Federal Center South

Sellen Construction/General Services Administration
Seattle, Washington

Federal Center South

Photo: Benjamin Benschneider

The American Council of Engineering Companies of Washington (ACEC) awarded Hart Crowser and Sellen Construction a 2014 National Finalist Gold Engineering Excellence Award for Structural Systems, and a 2013 Best in State Silver Engineering Excellence Award in the value to client category. The building has LEED Gold certification.

Hart Crowser helped design Energy Piles that both support the building and heat and cool it; implemented surface water controls that promote natural infiltration and eliminate stormwater piping; and devised a system to protect this waterfront site and the grounds from damage during a severe earthquake.

Sustainability. The project included design of infiltration galleries and rain gardens for on-site stormwater management. Hart Crowser conducted infiltration tests in the field using a specially designed and built large-format infiltration mechanism to better predict the permeability and infiltration characteristics of the soils above the shallow groundwater table. Hart Crowser worked with the civil engineer to adapt the testing program to the expected stormwater loading to improve the applicability of the results. Conversion of 4 acres of 100% impermeable surfaces to 50% pervious promoted natural infiltration of precipitation. Hart Crowser’s laboratory testing led to strategic locating of swales, channels, and open surfaces. In addition to the infiltration swales and the energy piles, we also figured out a way to leave about 2,000 century-old timber piles in place instead of removing and landfilling them, and then rely on them for partial stability of the new building in a major earthquake.