The American Society of Landscape Architects recently released 479 Green Infrastructure Case Studies. The case studies provide an informative snapshot of the type of green infrastructures are being implemented across the country. We are excited the two projects we submitted (The Pinnacle at Symphony Place green roof and Deaderick Green Street) were included in the list. You can check out the entire list here.
-Brian Phelps
Philadelphia’s Green City, Clean Waters Plan ,submitted to the EPA last September, has been signed by the PA Department of the Environmental Protection (PADEP) and the Philadelphia Water Department (PWD). According to PDW’s press release, it happened on June 1st. The approval of the plan is a big step in furthering green infrastructure’s legitimacy as a tool to address stormwater issues. The following are links to past post about the plan:
Triple Bottom Line of Green Infrastructure
Philadelphia Green Infrastructure Video
-Brian Phelps
Pinnacle at Symphony Place Green Roof , Nashville, TN
The following is a brief email interview we conducted with Steven Peck, founder and president of Green Roofs for Healthy Cities, a non-profit industry association promoting the planning, designing and building of green roof, and green walls.
GrID: It was good news to hear the green roof market continued to expand in 2010. We hope the trend continues. You were recently quoted in The Dirt, stating this expansion constituted an addition of 8-9 million square feet of green roofs. Can you provide more detail into what characterized this expansion (i.e. type of green roofs, clients, project types, etc)?
Steven Peck: We just posted a report on the industry survey at www.greenroofs.org that contains more detailed information about what types of buildings are green roofs being implemented on, the types of green roofs being installed, locations etc. It is a free, downloadable report that contains all of this information.
GrID: You acknowledge a lot of this growth is taking place in cities that are encouraging the development of green roofs through “significant public policy support”. What best policy or program practices are you seeing used most effectively in the United States? Any others you would like to see instituted?
Steven Peck: Most of the policy tools being used in the United States are economic in nature, in the form of tax incentives, increases in floor area for new developments, and grants averaging $5 per square foot. There are also procurement requirements for government buildings – a good place to start – as well as for any building that is receiving some for of government financial assistance. For publicly owned buildings, the fact that green roofs, if properly design, installed and maintained by a Green Roof Professional (GRP) extend the life expectancy of the waterproofing by two times or more, is a significant economic benefit for tax payers. Billions of square feet of flat roofs are torn off and replaced each year at enormous public and private cost.
The new versus retrofit markets are different, and the nature of the incentives to encourage green roofs varies from building type to building type, because the economics are very different. This makes it difficult to generalize about effectiveness. In buildings where green roofs can provide more direct benefits to the building owner – like condomiums, buildings that are air conditioned, schools and hospitals, the economic case is stronger. In buildings that are very cheaply constructed, not air conditioned, and the roofs are innaccessable to the occupants or public, greater government incentives are likely to be required owing to the fact that the benefits are more in the public realm. For example, green roofs are widely regarded as a best management practice by governments in dealing with the need to reduce and slow down stormwater, which in many cities results in significant water quality problems. So building owners can meet regulatory requirements by installing green roof systems.
In Canada, two jurisdictions, the City of Toronto and the City of Coquitlam have made green roofs a requirement in various classes of new development. The Green Roof By-Law in Toronto requires that all buildings over 2,000 square meters of floor area (with the exception of new industrial buildings) must install a green roof. This policy has already resulted in an estimated 1 million square feet of new green roofing that is now in the planning phase. It also levels the playing field and provides the design community with the opportunity to skip the ‘justification’ of the green roof and move right to ‘how do we get the most benefit’ from the green roof stage.
GrID: The new ANSI Fire and Wind standards seem to potentially have a big impact on the aesthetics of green roof design. Can you give us some insight into why and how they were developed? What has been the reaction to the new standards from the design side of the industry? Are they being widely used?
Steven Peck: The standards were developed because of largely unfounded concerns about these issues, but we need to address them in order to remove a potential regulatory barrier. During the development of the standards, we tried to maintain as much flexibility as possible in terms of design. It remains to be seen how widely these standards will be adopted, and ultimately what effect they will have on the aesthetics.
GrID: Green roofs can be initially significantly more expensive than traditional commercial roofing. As the green roof market has matured, are you seeing pricing coming down and/or seeing creative financing mechanisms that make it easier for property owners to choose to build a green roof on a new or existing building?
Steven Peck: Generally speaking, as a market begins to mature prices drop as a result of competitive pressures, more efficient implementation, and innovation in product and service delivery. This has happened in mature markets like Germany, and it is happening in more mature markets in North America. There is a danger however – buyer beware – that in just using price as a determinant, you may end up with a green roof system that fails to work effectively. These are engineered systems and all of the parts have to work together to achieve water tightness, structural integrity and the long term health of the plants. We’ve spent 10 years developing professional training programs in order to establish and promote best practices in the industry. This has culminated in the development of an occupational standard for a Green Roof Professional. There are more than 450 GRPs in the marketplace, so make sure that you are working with a GRP to help to ensure that your green roof doesn’t disappoint you.
GrID: What trends are you seeing in the green roof industry? What will the future of green roofs look like?
Steven Peck: We have recently developed three new courses that reflect some of the trends in the industry. Advanced Maintenance we launched in April in Washington to provide more detailed information on how to design, budge and implement effective maintenance practices. Maintenance neglect is one of the main causes of problems on a green roof. In November of last year, we launched a half day course on Urban Rooftop Food Production, a hot topic these days. We’ll be providing training in Toronto and New York this summer, two jurisdictions where there is a strong urban food movement. Water. In many regions, water shortage is already a problem, and only likely to get worse. Last year we developed an introductory course on Integrated Building and Site Water Management, in partnership with the American Society of Irrigation Consultants. This half day course will be available online, in our Living Architecture Academy, in June. Increasingly, green roofs will be integrated with other forms of green infrastructure, like green walls, and be designed to perform multiple functions – cool cities, biodiversity, food, improve photo-voltaic efficiency. We’ve still only scratch the surface of the full potential of these technologies.
Steven Peck, Hon. ASLA, and Founder and President of Green Roofs for Healthy Cities was recently interviewed by The DIRT while in Washington D.C. for the Living Architecture Symposium, (“Despite the Economy, Green Roofs Bloom“). In the interview, Mr. Peck quoted a recent survey of the green roof industry which reported that 8-9 million square feet of green roofs were built last year. This figure represented a 30% increase in market growth. Most of this expansion was focused in cities that have public policies in place that encourage and support green roof installation. The most intriguing statements in the article are those that helped quantify the economic impact of green roofs.
The post included some assertions that quantified the financial value of some of the soft benefits of green roofs. These included
“…average stormwater mitigation benefit is $4.26/sf” and a view of a green roof improves property values of nearby buildings by 11%”
These figures are based on research by Smart Cities Research Services, Montreal. “The Monetary Value of the Soft Benefits of Green Roofs” report prepared by Ray Tomalty, Ph.D. and Bartek Komorowski, MUP with the assistance of Dany Doiron, published last year. The report includes research on developing heuristic methods for quantifying seven soft benefits of green roofs: including: change in property values, marketing benefits, food production and food security, sound attenuation, stormwater retention, air quality, and green house gas (GHG) sequestration. The following is a summary of their findings:
I did not include the marketing figures in the table above, due the complexity of their findings.
Since there is little to no research specific to green roofs, the heuristic methods described in the report rely on other related research. Examples include:
Supply and demand play a critical role in determining one values and this is not any different for green infrastructure. For urban areas that may incorporate little to no green infrastructure (i.e. parks, green roofs, street trees) and are predominantly unsightly parking lots and roofs, projects that include green roofs should be more valuable and those properties surrounding it should benefit in some way as well. The report provides a great starting point for financially quantifying the soft benefits of green roofs. Over time, data specific to green roofs will eventually become available and we will be able to more accurately quantify their specific benefits.
-Brian Phelps
Earlier this year the Center for Neighborhood Technology (CNT) released the publication “ The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental and Social Benefits”. The publication is a great summary of the benefits of Green Infrastructure and goes a step further by providing data to help communities quantify many of its benefits.
The document includes two example demonstration projects. The first is for a green roof project on a single site and the other seeks to illustrate the benefits of the green roof site if expanded to a neighborhood scale. The authors point out that full life-cycle analysis was not a part of the scope of the analysis included in these demonstrations.
In addition, they offer a series of considerations and limitations of the data included. These points are helpful to consider when applying the information within the report. These include considering the full life-cycle analysis, local performance and level of benefits realized, spatial scaling and thresholds, temporal considerations and scale discounting, operation and maintenance, price variability, and double counting.
The concept of “discounting” described in the report was interesting. It recognizes that society typically values present benefits over future benefits. The following is an excerpt describing this concept:
“The term “discounting” refers to the adjustment one makes to account for future uncertainty (or the opportunity cost of money: a dollar today is not worth the same as a dollar five years down the road). Our society generally values what an investment gives us in the present more than what we might get for it in the future. The reason for this is future uncertainty, and as such, the future value or benefit of an investment must be adjusted or discounted. It is a technique widely used in benefit-cost analyses to understand and compare a project’s implications (its rate of return) over a given temporal scale.”
Overall the report is a helpful resource in quantifying the benefits of green infrastructure. The additional external links and resources provide additional tools and are worth exploring. You can find the full report on CNT’s website.
Last week, the Economist in an articled titled “Trees grow in Brooklyn” reported on U.S. cities implementing green infrastructure strategies to address the pollution of their waterways from storm water runoff. The article focused primarily on New York City and Philadelphia.
According to the article nearly 27 billion gallons of untreated water overflows into the New York harbor each year. NYC’s recently released green infrastructure plan seeks to address run-off from 10% of the impervious surfaces in the City with green infrastructure storm water strategies that range from rain barrels to pervious pavements to green roofs.
The plan estimates that on average the cost per gallon of Combined Sewer Overflow (CSO) avoided ranges between $1 to $2 per gallon. In addition, the City calculates that over a twenty-year period, it will receive between $139 million and $418 million in additional triple-bottom line benefits (i.e. energy savings, increase in property values, health) from the green infrastructure.
While NYC’s strategy is also employing grey infrastructure, they see the combination of the two costing less than a grey only approach. The cost of the green-grey strategy is approximately $5.3 billion of which $2.4 billion makes up the cost of the green infrastructure. This is $1.5 billion less than the grey only solution.
Chris Strickland, a deputy commissioner with the New York’s Department of Environmental Protection sums it up in the article saying that this (green infrastructure plan) is a way of achieving more than one thing with tax dollars.
Link to NYC Green Infrastructure Plan
-Brian Phelps
Last week I attended the American Society of Landscape Architect’s (ASLA) annual meeting in Washington D.C. It was invigorating to hear about promising green infrastructure related projects being plan and constructed across the United States. One favorite was Herbert Dreiseitl’s presentation on the promise of water. His approach and sensitivity to water was inspiring.
Many of the conference sessions reinforced the multiple benefits of green infrastructure projects and the importance of continuing to build the data supporting these benefits. In addition, it was clear that green infrastructure projects are addressing multiple political agendas and problems facing our cities. As a result, municipalities are able to seek funding from a variety of traditional and non-traditional sources. When considering these sources, it is critical to understand and quantify the benefits of a project.
While all green infrastructure projects have multiple benefits, depending on the approach, site, and its context, each project will have a unique combination and varying impact. Understanding this “benefit fingerprint” is helpful in successfully targeting funding sources. It also opens up the possibilities of non-traditional sources and helps others see the project with a broader perspective.
I recently came across this video covering Philadelphia’s Green Infrastructure Efforts. It was created by GreenTreks, an award-winning Philadelphia-based non profit communications organization dedicated to educating people about the interconnectedness of environmental, societal, economic, and individual health. For more information and links to other resources on Philadelphia’s triple bottom line green infrastructure strategy see our past post Triple Bottom Line of Green Infrastructure.
Metropolitan Nashville-Davidson County’s Green Infrastructure Master Plan is now available on Metro Water Services’ website. The plan was prepared by amec, Hawkins Partners, Urban Blueprint, and the Low Impact Development Center. The plan includes the following:
Click here to download the entire plan in PDF format
Kim Hawkins, a principal with our office, recently spoke at this years StormCon in San Antonio, TX. She and Jim Snyder P.E., who at the time of the design and construction of the street was with Metro Nashville Public Works and who is now with Metro Nashville Water Services , spoke about the process of bring Nashville’s 1st Green Street to fruition. The following is the abstract about the presentation.
ABSTRACT: DEADERICK STREET – TENNESSEE’S 1ST GREEN STREET
Nashville, TN
Nashville Metro Public Works, Client
Hawkins Partners, Inc worked with the Office of the Mayor and Metro Public Works to transform a historically and civically significant corridor in the downtown area which serves as a physical connector between the city/county courthouse and the state legislative arm of government. Prior to the renovations, the street had become most widely known as the central transfer point for the Metro bus system. In the fall of 2008 the bus system’s hub was relocated one block north to the ambitious Music City Central, presenting an opportunity to re-envision the street itself.
Deaderick Street sits within the Kerrigan Basin, one of Nashville’s Combined Storm Sewer (CSS) basins, that has historically been subject to overflows., it is Nashville’s first implementation of LID features in the public right-of-way, the first green street in Tennessee and one of the first green street applications in the southeast. The renovations to the street primarily focused on addressing stormwater issues and urban trees. Pervious surface within the right of way was increased by 700% through the use of rain gardens, pervious concrete and .bioswales were implemented in pedestrian bulbs at the intersections. The site design worked within the context of the existing street and the existing storm drainage system, retrofitting existing storm drains to serve as overflow only. Rain gardens and bioswales were designed with engineered soils to allow infiltration and planted with plants, including many natives, that are adaptable to the extremes of wet and dry conditions. Based on Nashville’s historical rainfall patterns, infiltration rates and variable design factors, it is estimated that over 1.2 million gallons will be removed from the CSO system on an annual basis through this three block urban street..
In addition to the stormwater aspects of Deaderick, a number of other sustainable features were incorporated into the street, including LED lighting, recycled steel site furniture, crushed concrete as base aggregate material, fly ash for concrete and solar powered parking meters.
Green Infrastructure Digest 
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