2008 - 2012
Portland's Ecoroof Incentive
Developers and business owners around the world are designing, building and managing
their properties in a way that reduces negative impacts to air, water and the earth.
The result is a growing interest in using ecoroofs.
Absorb rain to decrease stormwater runoff
An ecoroof is a layer of vegetation over soil on top of a waterproof membrane. Ecoroofs replace conventional roofing with a living, breathing, vegetated roof system.
- Save energy
- Reduce pollution and erosion
- Help preserve fish habitat
- Absorb carbon dioxide
- Cool urban heat islands
- Filter air pollutants
- Increase bird and beneficial insect habitat
- Provide urban green space
From 2008 to 2012, Environmental Services offered property owners and developers an ecoroof construction incentive of $5 per square foot. Ecoroof costs vary according to project size, design and complexity. Environmental Services granted almost $2 million in incentives that helped fund over 130 projects that created more than 8 acres of ecoroofs that manage an average of 4.4 million gallons of stormwater annually.
Incentive Project Examples
Total Cost - $8 per square foot
This residential ecoroof project on a home built in 1961 completely replaced a conventional roof. New framing over the existing roof left space to install insulation under the ecoroof. The framing supplied the structure necessary to support the ecoroof's added weight.
Photo by David McLaughlin
Reed College Ecoroof Terrace
Total Cost - $27 per square foot
This ecoroof above the Reed College Performing Arts Building provides an outdoor terrace with view of the campus. The irrigation system uses non-potable water from Reed Lake, an on-campus lake fed by Crystal Springs Creek. Reed biology department students and staff helped select ecoroof plants to test plant varieties and soil, and monitor environmental factors throughout plant life cycles.
Total Cost - $12 per square foot
The 32,000 square foot ecoroof on the Ramona building is one of the largest in Portland. The ecoroof installed on a wood fram structure integrates ecoroof technology beneath solar hot water and photovoltaic panels - a mutually beneficial partnership. The city monitors how well plants grow in two different soil types on the ecoroof.
Common Grounds Wellness Center
Total Cost - $7 per square foot
The ecoroof on the Common Grounds Wellness building replaced part of the original conventional roof. Although the building's structure couldn't support a full ecoroof, the partial ecoroof still captures stormwater and filters pollutants.
Project Requirements and Selection
In four years, more than 130 projects received the ecoroof incentive. More than 1.8 million incentive dollars helped build more than 360,000 square feet of ecoroofs around Portland. Those ecoroofs capture and absorb about 4.4 million gallons of stormwater each year.
Projects that received the ecoroof incentive had to be in the Portland city limits, be designed to manage stormwater, and be feasible and buildable within two years of receiving funds. Environmental Services also evaluated projects on cost estimates, size, ratio of green roof to total roof area, visibility, innovation, and the opportunity to engage diverse communities.
Ecoroofs keep millions of gallons of stormwater from flowing into Portland's sewer system.
Ecoroof Incentive Projects Map
Outreach and Resources
Outreach and technical development were key elements in the success of the ecoroof incentive. As part of the program, Environmental Services offered annual seminars to build awareness and connect interested property owners to ecoroof service providers. Staff developed technical resources, conducted research, and admiminstered the Ecoroof Blog to get current information to interested parties.
Staff monitoried ecoroofs to gather and share information about stormwater management performance and habitat benefits. Environmental Services help form the Greenroof info Think-tank (GRiT) to raise awareness of ecoroof benefits and promote ecoroof construction.
The ecoroof incentive elements will continue supporting ecoroof construction in Portland in the future.