An ecoroof is a vegetated roof system used in place of a conventional roof. Ecoroofs are comprised of several layers that include a root barrier, waterproof membrane, drainage, soil system, and plants. Similar to landscaping your yard, the viability of any ecoroof is dependent on many variables such as climate, exposure, soil and plant type, and initial maintenance. With those variables in mind, there are many design opportunities to transform a conventional roof into a beautiful, functional and beneficial space.

Portland has many ecoroofs in bloom, design and under construction. Projects include a completed 23,000-ft² lightweight roof on Portland State University’s Broadway Housing Complex; an ecoroof café and soccer field on an industrial building in design; and a completed accessible roof on the Multnomah County building that blooms beautiful wildflowers in the Spring and Summer.  

Ecoroofs extend roof lifetime two or three fold, add insulation to a building, create additional useable space, are a City-approved stormwater management technique, and qualify owners for City incentives. They also have many benefits that are typical of any living, natural system such as reducing stormwater runoff, cooling ambient air, capturing air pollution and carbon dioxide, mitigating noise and glare, and creating wildlife habitat- all of which are very desirable services in Portland.

In addition to these benefits, there are several incentives to install an ecoroof in Portland. Starting in late 2006, homeowners and building owners will be eligible for a maximum 35% discount on their municipal stormwater fee for qualifying ecoroofs (see Clean River Rewards below). Projects that install ecoroofs in the Central City Plan District are eligible for a floor area ratio bonus, which increases the building’s allowable area, and can use ecoroofs to conform to the Central City Design Guidelines. Ecoroofs are also a means to comply with the City’s Stormwater Management Manual that applies to all new and redevelopment projects.

The City of Portland’s ecoroof program is a collaboration between the Bureau of Environmental Services (BES) and the Bureau of Planning and Sustainability (BPS).

Learn More:

Bureau of Environmental Services (BES)

Ecoroof Program website

BES Clean River Rewards Stormwater Discount Program

Ecoroof and stormwater feature tours

Central City Design Guidelines - "Integrating roofs…."

The Guidelines call out ecoroofs as a compliance strategy for the "Integrating roofs and the use of rooftops" requirement. See p. 130.

City of Portland Stormwater Management Manual

One tool by which the City complies with Federal ESA requirements for the protection of Chinook and steelhead salmon and the Clean Water Act. The manual spells out the stormwater management requirements for development projects in Portland and ecoroofs are one tool by which to comply with the requirements.

Central City FAR bonus

Buildings can receive bonus FAR based on three ranges of ecoroof coverage in relation to the building’s footprint: 10-30%, 30-60% and 60% or greater earns one, two and three square feet of additional floor area per square foot of ecoroof respectively.

City of Portland Zoning Code Title 33, pp. 510-27,30

City of Portland Green Building Policy

This city resolution requires that all new municipal projects are designed and constructed with an ecoroof and/or Energy Star rated roof material. All roof replacement projects must include an ecoroof when technically feasible.

City of Portland Green Investment Fund

Awards grants to highly innovative and comprehensive green building projects in the city. Past projects have included ecoroofs.