Washington State University - Applied Building Science - Portable Classroom Project
        http://www.energy.wsu.edu/projects/building/portable_prj.cfm

US Environmental Protection Agency - Portable Classrooms
        http://www.epa.gov/iaq/schooldesign/portables.html

Extracted from EPA link above:
"Although portables are often the lowest cost option for housing students, they range in quality. Care should be taken during specification and selection to ensure that the students' health is not compromised for inexpensive, low quality designs. When districts specify a portable design, they typically create a term contract that other districts can use to purchase the same (or slightly different) design. This practice (often called "piggy-backing") can save a district valuable time and money on specifications and approvals, but it can also compound poor decisions made in the original procurement."

OSPI - Superintendent of Public Instruction - State of Washington
        http://www.k12.wa.us/

National Clearinghouse for Educational Facilities (NCEF) - Created in 1997 by the U.S. Department of Education
        http://www.edfacilities.org/rl/portable.cfm

Modular Building Institute
        http://www.mbinet.org/

Washington State Labor and Industries - Factory-Built Structures
        http://www.lni.wa.gov/TradesLicensing/FAS/default.asp

Washington State Labor and Industries - Prevailing wage and public works
        http://www.lni.wa.gov/TradesLicensing/PrevWage/default.asp

Council of Educational Facility Planners International (CEFPI) Pacific NW Region
        http://www.cefpi.org/i4a/pages/index.cfm?pageid=3302

WAMOA is an organization of Educational Facilities Maintenance Professionals in Washington State
        http://www.wamoa.org/index.html

King County Directors' Association - Classroom Contract Awards
        http://www.kcda.org/KCDA_Awarded_Contract_AEPA_006-2_Modern_Building.htm

        http://www.kcda.org/KCDA_Awarded_Contract_AEPA_006-2_Williams_Scotsman.htm