Informational Video on Green Roofs
Here’s our informational video on green roofs and the green roof rebate program going on in DC right now- thanks to the Anacostia Watershed Society for letting us interview them and get up to see a green roof in DC!
Banking on Green Infrastructure: A New Study
A new study has been released that summarizes how green infrastructure can be beneficial to cities, particularly with regard to stormwater runoff problems. The Atlantic wrote an article on the report, and our summary is below. You can also access the full report here– it’s an interesting read!
American Rivers, the Water Environment Federation, the American Society of Landscape Architects and ECONorthwest (2012). Banking on green: A look at how green infrastructure can save municipalities money and provide economic benefits community-wide. Washington, DC.
This study provides a comprehensive look at the problem of stormwater runoff, how it has been dealt with in the past, and what the benefits of using green infrastructure to reduce stormwater runoff are. Typically in urban areas, stormwater, which is precipitation that becomes polluted as it travels through the streets of a city, has been managed through a system of drains and tunnels that take the water to a sewage treatment plant. However, when the runoff exceeds the limit of the plant, the excess water is dumped into a city’s rivers, and can overwhelm the rivers or be harmful to the wildlife population. The study suggests that green infrastructure, including green roofs, are a good and cost-effective way for a city to deal with the problem of excess stormwater runoff. The article states that “By reducing the volume of runoff entering sewer systems and increasing natural features that can soften the effects of storm surges and flooding, green infrastructure can add resiliency to local climate change adaptation planning.” (p 4) It also adds that although some may think that green infrastructure is expensive to implement and maintain, in reality the maintenance costs can be lower than those of a traditional stormwater runoff system, and the benefits are long-term. Buildings that have green infrastructure may also increase in value, and can save a city literally billions of dollars over the course of years. In New York City, for example, a proposed plan to manage stormwater using both green and traditional infrastructure is projected to save 1.5 billion dollars over 20 years. This study includes multiple case studies on green infrastructure, and is a good overview of the stormwater runoff benefit of green roofs, while also mentioning the many other benefits green infrastructure can bring to an urban area.
Video Clips and Green Roof News
We’re hard at work on an informational video on green roof technology, it’s implications, and political context, but in the meantime, here are some clips from our interviews with the Anacostia Watershed folks. Also check out some new articles on green roofs, one from CNN on the “Wonder Forest” that is envisioned for Beirut, and another from NRDC on Toronto’s green roof requirements and the benefits of green roof technology.
Michael Lucy on perceptions of green roofs:
Laura Washington on how green roofs can provide much-needed green space in cities:
The Structure of Green Roofs
While green roofs are a relatively simple technology, for a green roof to function properly it must include several components and be installed correctly. There are a few different types of green roof, and they are classified according to their depth and maintenance requirements. Classifications of green roofs include: lightweight extensive, extensive, semi-intensive, intensive, roof garden, and bio-diverse/wildlife. Intensive roofs are typically those that require a greater amount of maintenance, and may require feeding or manual irrigation. By contrast extensive green roofs are virtually self-sustaining, and usually consist of an absorbent plant such as a Sedum plant which only needs to be maintained annually. Extensive green roofs may not be accessible to the public, whereas intensive green roofs are those that can be used by the building’s occupants as a recreational area.
Green roofs consist of several layers underneath the actual soil and vegetation. Most green roofs have a vapor control layer on top of the roof itself, insulation, a waterproof membrane, drainage layer, and then the growing medium and plants. Just covering up black city roofs, which are one of the biggest sources of heat during the summer months, can greatly reduce a building’s temperature and the temperature of the air around a building. Although green roofs are not difficult to install, a building must meet the necessary requirements to ensure the weight of the roof will be supported.
The Benefits of Green Roofs
So, what’s all the fuss about green roofs anyway, and why are cities encouraging buildings to install them? Green roofs have many benefits, which we will explain in more detail in our upcoming informational video and research paper, but here are some of the main highlights. Also check out Green Roofs for Healthy Cities for an extensive lists of the private and public benefits of installing a green roof on your building.
Green roofs benefit us by:
Reducing storm water runoff
- Green roofs absorb substantial quantities of storm water and filter pollutants from runoff, preventing overflow of sewer systems and reducing pollution levels in local water sources.
Mitigating the “urban heat island” effect
- By absorbing sunlight that would otherwise be converted to heat energy, vegetation offers a cooler alternative to traditional black rooftop material, which is one of the hottest elements of a city environment. Additionally, the regular dew and evaporation cycles of plants have a collective air cooling effect.
Lowering energy costs for buildings
- Green roofs provide improved insulation to buildings, helping retain heat in the winter and moderating higher roof temperatures in the summer.
Filtering pollution
- In addition to filtering pollutants from rain water, roof vegetation can capture airborne pollutants and defuse noxious gases. Plants improve air quality by absorbing carbon dioxide and increasing oxygen levels.
Reducing noise
- Green roofs can help reduce noise pollution by insulating a building from external acoustics, especially low-frequency sounds. Roof vegetation can diminish external noise by approximately 40-50 decibels.
Toronto mandates green roof installation
A green roof on Toronto's City Hall
Toronto has become the first city in North America to mandate that all buildings over 2,000 square meters are covered at least 20% by a green roof. The law has been in place since 2010 but will apply to new industrial developments starting April 30th of this year. The government website has a section on benefits of green roofs, including reduced energy costs, storm water runoff, and improved air quality. Read about the program here, and check out their website.
Greener Heights Visits a Green Roof
On Friday we were lucky enough to meet up with Mike Lucy and Laura Washington of the Anacostia Watershed Society to look at one of the green roofs they have helped implement right here in the District. We visited the green roof at the Department of the Environment in NorthEast DC, and were able to go out onto the roof and interview Mike and Laura about green roofs and the green roof rebate program that they run here, which helps businesses pay for green roof installation. The green roof we saw had Sedum plants on top of the flat roof, and was not accessible to the building’s occupants. However, the Anacostia Watershed Society has also helped install green roofs that have different vegetation and which can be used by the building’s occupants- Laura and Mike emphasized the many benefits to individuals green roofs can have, and it’s even been shown that buildings with green roofs find their occupants are happier and more productive than in regular buildings. Green roofs also have health benefits, and hospitals and health facilities are using them more and more for their therapeutic purposes. We look forward to sharing our final informational video with you, and in the meantime check out our slideshow of Friday’s green roof adventures- it was a beautiful clear day and we were treated to a fantastic view of DC!
Green Roofs and Urban Farming
There have been several items in the news lately about green roofs and urban farming- when the green roof concept is taken to another level, and produce is grown on top of city roofs. Urban and greenhouse farm business Brightfarms has announced that it will build a 100,000 square foot “garden in the sky” on top of a warehouse in New York, which will make it the largest rooftop farm in the world. The farm will produce 1 million pounds of produce a year, and can prevent up to 1.8 million gallons of storm water from running into local waterways. The New York Times also wrote an article on rooftop gardens that have been appearing more and more in low-income housing projects in the city, and how they can promote healthy eating as well as provide all the benefits of green roofs. Check out the articles and watch the Ted Talk that Brightfarms CEO Paul Lightfoot gave on local urban farming, below.
National Sustainable Design Expo in DC
From April 21-23rd the 8th Annual National Sustainable Design Expo will be held on the National Mall in Washington, DC. Exhibitors will showcase the newest technologies in environmental sustainability, and students, scientists, government agencies and businesses will come together to discuss innovations that can advance economic growth while also reducing environmental impact. We hope that green roofs are a topic of conversation! More information can be found on their website here.
Green Roofs on “Earthrise”
Check out this video from Al Jazeera English’s “Earthrise” on green roofs in New York City: All across New York City roofs are turning green. In the last few years residents of the Big Apple have converted the tops of hundreds of buildings into gardens. As well as providing a retreat from city life these gardens help reduce water runoff.
Bibliographic Reviews
You can now find the first batch of Greener Heights bibliographic reviews in the “Our Work” section, and here. Below is the list of our initial sources, and make sure to contact us via Twitter, Facebook, or greenerheights@gmail.com if you would like us to include your source in our research!
1) About green roofs. Green roofs for healthy cities. Retrieved March 10, 2012, from http://greenroofs.org/index.php/about-green-roofs
2) Getter, Kristin L. & Rowe, D. Bradley (2006). The Role of Extensive Green Roofs In Sustainable Development. HortScience, 41(5): 1276-1285. 2006. from: http://hortsci.ashspublications.org/content/41/5/1276.full.pdf
3) Kokogiannakis, George, Annegret Tietje, and Jo Darkwa. “The Role of Green Roofs on Reducing Heating and Cooling Loads: A Databate across Chiense Climates.”Procedia Environmental Sciences 11 (2011): 604-10. Www.pubmed.gov. Web. <http://ac.els-cdn.com/S1878029611009170/1-s2.0-S1878029611009170-main.pdf?_tid=ea9dae3f0e234cebc3a13060bc7e4258&acdnat=1333026505_80c4bcff8591594a410605f8e4175583>.
4) Martin, A. (2005). Green roof manual. Retrieved from http://www.pomegranate.org/wp-content/publications/Pomegrante-Center-Greenroof-Manual-2005.pdf
5) Martin, B. (2012, February 28). Lofty ambitions: why green roofs are the future of urban gardening. Ecologist, Retrieved from http://www.theecologist.org/green_green_living/gardening/1261593/lofty_ambitions_why_green_roofs_are_the_future_of_urban_gardening.html
6) Oberndorfer, E., Lundholm, J., Bass, B., Coffman, R. R., Doshi, H., Dunnett, N., Gaffin, S., & Köhler, M., Liu, K., Rowe, B.(2007). Green roofs as urban ecosystems: Ecological structures, functions, and services. BioScience, 57(10), 823-833. doi: http://dx.doi.org/10.1641/B571005
7) Sonne, Jeffrey (2006). Evaluating Green Roof Energy Performance. ASHRAE Journal. Vol. 48, February 2006. from: http://www.fsec.ucf.edu/en/publications/pdf/FSEC-CR-1659-06.pdf
8) Susca, T., S. R. Taffin, and G. R. Dell’osso. “Positive Effects of Vegetation: Urban Heat Island and Green Roofs.” Environmental Pollution 9th ser. 159.8 (2011): 2119-126. Www.pubmed.gov. Web. http://www.ncbi.nlm.nih.gov/pubmed/21481997.
New Canadian Report on Green Infrastructure
A report released yesterday by the Green Infrastructure Ontario Coalition says that green infrastructure is a cost solution that policy makers should pay attention to in the coming months: “The Case for Green Infrastructure in Ontario argues taxpayer dollars spent on green infrastructure offer a greater return on investment because of the multiple economic, health and environmental benefits. The report, co-written by the Coalition and Ecojustice, examines how other jurisdictions in North America are leveraging the rewards from public policies and investments in green infrastructure, and makes specific, practical recommendations to the provincial government on how to similarly benefit.”
See the full report here
Potential interview subjects
Here are some of the people we would like to talk to for background research and our video. If you are an expert on green roofs, the environment, or just think they’re pretty cool, email us at greenerheights@gmail.com. Don’t forget to like us on Facebook and follow us on Twitter too!
Keith Agoada – Sky Vegetables, Founder
Nick LeVigne – SAIC – Sustainability Lead
Peter Ensign – Executive Director, DC Greenworks
Jeanette Stewart – Founder and President, Lands and Waters
Michael Perry – Building Logics
Dr. Hamid Karimi and Rebecca Stack, District Department of the Environment District of Columbia
Robert Goo, Office of Water Environmental Protection Agency
Jennafer Bonello – General inquiries contacts for World Wildlife Fund, who has the biggest green roof in the District
Welcome to Greener Heights
Welcome to the Greener Heights blog! We are part of a group project exploring the technology of green roofs, and this is where we will post updates on our project, recent news on green roofs, and link to our video and poster. If you have any questions please feel free to contact us at greenerheights@gmail.com, and follow us on Twitter, @greenerheights.
greenerheights 