in the news
Back to Guest Features
guest feature article
Portland Builds Over 100,000 Square Feet of Greenroofs in 2011
By Casey Cunningham
City of Portland’s Sustainable Stormwater Division
All Photos and Graphics Courtesy of the City of Portland
Portland has again topped the 100,000 square foot (sf) mark for new greenroof construction in a calendar year, making 2011 the fourth best year for greenroof construction.
The 2011 total of 102,000 sf comprises the green, vegetated portions of extensive ecoroofs and intensive roof gardens constructed within the city limits of Portland, Oregon. This figure does not include greenroofs constructed in the surrounding metropolitan area. These numbers are a bit low as they comprise only projects which City staff are aware of, which are usually the more conspicuous, larger ones.
About 90% of this year’s greenroof construction were ecoroofs. Of those ecoroofs, by area, 65% were commercial, 25% were municipal and the remaining 10% were single-family residential or institutional. By quantity, there were 39 ecoroofs built in 2011 and half of them were residential.
|Residential Ecoroof in Portland, OR|
This year’s ecoroofs included several projects which layered solar panels over the vegetation, a mutually beneficial combination. Others tested new design methodologies, such as designs specifically for pollinators, lightweight systems for retrofits, and designs that don’t require summer irrigation. Project size ranged from informational kiosks to bike sheds, to accessory dwelling units to full block developments.
Notable commercial ecoroofs from 2011 include The Ramona Apartments, Portland’s largest contiguous ecoroof yet at 32,000 square feet, with a smaller roof garden below. This new building on the edge of downtown includes a community center and commercial space below the apartments, all of which is covered entirely with vegetation. Solar panels for electricity and water heating over the ecoroof provide dappled shade to the plants.
Other new housing projects include the Bud Clark Commons, a downtown housing, shelter and day center for the homeless, and Killingsworth Station, a 21,000 sf mixed-use commercial and residential building on the light-rail line. This ecoroof also demonstrates 100% vegetation coverage beneath photovoltaics. Ecoroofs additionally cover three separated parking garages, and all other runoff from the site and adjacent roads is managed in parking lot swales and green streets.
|Durham Stormwater Bike Corral|
The Durham Stormwater Bike Corral brings together green streets with public art and bicycle parking under an ecoroof, adjacent to one of Portland’s craft breweries. The Gunderson habitat ecoroof is in an industrial zone and was designed as an island for pollinators with native plants, varied topography, and a monitoring protocol.
|Oregon Health and Science University Ecoroof |
Other organizations such as Oregon Health and Science University, and the Bonneville Power Administration retrofitted existing buildings to include ecoroofs and roof gardens visible to tenants and patients.
|The City of Portland Screening Facility |
The City of Portland added several new ecoroofs to its buildings per the Green Building Policy, including the Wet Weather Screening Facility, which pilots a new, simplified design benefitting from the use of lightweight cinder as mulch. This sedum roof is designed to not need summer irrigation, which is a trick considering Portland’s summer droughts.
The City also worked with Dr. Stephan Brenneisen of The University of Basel to design and construct test plots that use lightweight, local materials, such as straw and native site soils, to create lower-cost, more resource-efficient alternatives for retrofitting roofs. These techniques have been successful in Europe and have also proved valuable as habitat to decreasing populations of native pollinators and ground-nesting birds.
The Ecoroof Initiative
The City of Portland is once again accepting applications for ecoroof incentives to spur construction of new ecoroofs in Portland on April 1, 2012.
|Portland Residential Ecoroof|
The incentive pays up to $5 per square foot for new ecoroof projects in the city. Ecoroofs in Portland typically cost between $5 and $20 per square foot. Industrial, residential, commercial and mixed-use projects are eligible. The deadline to apply for this cycle is June 1, 2012.
Since the incentive program began, the city has approved $2.1-million for 159 projects, resulting in 10 acres of new ecoroof. 86% of this year’s constructed square footage utilized this funding. There are currently 332 ecoroofs in Portland covering over 16 acres, all of which root from back in 1998 when a City employee tossed soil from his backyard onto his garage and watched what happened, creating Portland’s first intentional ecoroof.
|Gunderson’s Habitat Ecoroof |
The ecoroof incentive is part of the Grey to Green effort to expand Portland’s green stormwater management infrastructure, protect natural areas and improve fish and wildlife habitat. Those interested in the incentive can apply online or download a PDF application at www.portlandonline.com/bes/ecoroofincentive.
For technical information about greenroofs and information about the program, visit www.portlandonline.com/ecoroof.
Also stay tuned for more information about our Ecoroof event scheduled for May 18th, which will include speakers, a vendor fair and tours.
Thank you, and congratulations to everyone involved in the industry and we look forward to setting a new record this year.
City of Portland’s Sustainable Stormwater Division
Casey Cunningham has been a landscape architect with the City of Portland’s Sustainable Stormwater Division for six years. He designs green streets and other low-impact, vegetated systems that manage stormwater while improving wildlife habitat and adding green (=dirt and plants) to urban spaces. Casey monitors ecoroofs for their value to birds and insects.
Contact Casey at: Casey.Cunningham@portlandoregon.gov
The opinions expressed by our Guest Feature writers and editors may not necessarily reflect the beliefs of Greenroofs.com, and are offered to our readers to simply present individual views and experiences and open a dialogue of further discussion, debate and research. Enjoy, and if you have a particular comment, please contact the author or send us an email to: email@example.com.
Back to Top