Ballard Library

Seattle, WA
Garden Roof® AssemblyGarden Roof® Assembly: ExtensiveGarden Roof® Assembly: Sloped ApplicationsWaterproofing
Project Type: 
New Construction
 sq. ft. pi. ca.
Completion Date: 

Libraries are traditionally stark repositories of knowledge. Installing a green roof was an opportunity to generate community interest in green design to make this facility a dynamic teaching tools for sustainable design and environmental awareness.


The green roof was incorporated as part of an overall strategy to reduce and conserve energy costs where possible. Solar (photovoltaic) panels provided by the Seattle City Light Green Power Panel installed on the northern edge of the roof will monitor the amount of electricity captured and collected onsite. Energy generated from these panels is fed back into the city's power grid, reducing the library's energy bills. Additionally various rooftop sensors measure wind speed, direction, sunlight etc. 


The gently curving roof is visible from the periscope and observation deck and invites visitors to engage in the green roof's ecology above the street. The project illustrates green buildings are feasible within a modest budget, presenting the community with an ideal example of benefits realized when sustainable design combines with extraordinary architecture. 


As the site is in an urban setting, the challenge was to develop the site in a restorative manner. Formerly home to a bank and a parking lot, hardscape compromised 100% of the lot coverage. Today, combined with the green roof and planters at the building perimeter, the hardscape has been reduced to 20% of the lot coverage.


The seamless waterproofing membrane used for the green roof project, Monolithic Membrane 6125EV-FR® (fabric reinforced, environmental grade, 25% recycled content), is a hot fluid-applied, rubberized asphalt that forms a long-lasting tenacious bond to the substrate. MM6125EV-FR's® unique formulation, which includes inert clay fillers, provides excellent resistance to acids and fertilizers. 

2006 Green Roofs for Healthy Cities Award of Excellence - Extensive Institutional Category2006 AIA/COTE Top Ten Green Project
Bohlin Cywinski Jackson
General Contractor: 
PCL Construction Services, Inc.

Recent Press

  • November 26, 2019

    Palo Alto, CA. (November 26, 2019) There are many reasons to incorporate a green or living roof into a design, including energy conservation, water management, and financial benefits.  For one project in Palo Alto,...

  • November 11, 2019

    Climate change and stormwater management

    A new color is emerging in the roofing field; after green roofs and white roofs, now here is the blue roof. The dense nature of urban areas, combined with the increased intensity of rain events and...

  • May 2, 2019

    CHICAGO, ILLINOIS (May 2, 2019) Very near Lake Michigan in Chicago, Northwestern Medical Center faced several challenges in bringing a new campus building to life. Designed by Perkins+Will, the project involves...

  • October 17, 2018

    Hydrotech, a recognized leader in the vegetative roofing market, today announced the availability of the Fourth Edition of the company’s widely acclaimed Garden Roof® Planning Guide. For the last five years, updated...