22. Multnomah County Ecoroof
Multnomah County Building
Stormwater facility: Multnomah County Ecoroof
Facility location: 5th floor
Type of facility: Ecoroof
Date of installation: July 2003
Impervious area managed: 15,420
Size of facility (ecoroof area): 11,893 ft2
Cost: $17/ ft2
At the time of installation, this green roof was the largest in the City of Portland. It is a retrofit green roof located on the 5th floor of the Multnomah County Building and is accessible to the public during business hours. Interpretive displays are included on the 3,000 sq. ft. outdoor patio area and provide information about the installation, composition and benefits of this green roof. The roof has 6� of lightweight soil and is planted with sedum, fescue, wildflowers, perennials and ornamental grasses. Students and staff from Portland State University will monitor stormwater reductions and energy savings.
Project team
Architect: Carleton Hart Architecture
Landscape Architect: Macdonald Environmental Planning
Mechanical/Electrical Engineers: Interface Engineering
Structural Engineers: KPFF Consulting Engineers
Green Roof Consultant: Mary-Anne Boivin
Funding and Support
- $50,000 - Environmental Services Stormwater
- $75,600 - DEQ
- Fescue and wildflower seed mix from Turf Seed Inc.
- Protection board donated by Tremco