Believe it or not, what makes Seattle so attractive to data centers isn't just our heavy concentration of tech companies(though that helps).

The strength of the Seattle-region data center market is driven by diversity,climate,and energy costs, Sellen Construction senior project manager Tom Boysen(wearing his data centercamouflage) tells us. Seattle has a number of different industries needing data center space--medical records, enterprises needing back-end systems, website operators, Internet retailers, cloud hosting, colocation providers, and R&D institutes, Tom notes, a diversity that spurs demand.

Seattle's climate is mild year-round, allowing highly efficient cooling systems for lower operating costs. Tom also notesthat the region enjoys relatively low-cost power, fueled by green hydroelectric generation. Sellen recently tapped Tom to lead the firms work on data centers. Hes been in the field for 20 years, doing projects for the Amazon, Microsoft, Swedish Medical Center, Yahoo, and others. He recently worked on the redevelopment of Federal Center South in Seattle, which is ranked in the top 1% of energy-efficient office buildings in the country. Pictured: Microsofts R&D data center, OneLab, a Sellen project.