Interview with Green Roof for Healthy Cities Founder Steven Peck

20 05 2011

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. 





Quantifying the Financial Value of the Soft Benefits of Green Roofs

6 05 2011

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





Valuing Green Infrastructure

23 03 2011


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.

-Brian Phelps





Eco-roofs in Portland: Creating Habitat [VIDEO]

2 04 2010

Screenshot of KGW News Story

I came across this news segment from KGW News in Portland regarding the City’s eco-roof initiative and the recent visit by Dusty Gedge, president of the European Federation of Green-roof Associations. In addition to many of the other benefits of green roofs, the city is also promoting the creation of eco-roofs to establish habitat for dry riverbed species in particularly the diverse species of birds that migrate through the city. I couldn’t embed the video but here is a link to it and the transcript.  Tom Liptan, an Environmental Specialist with Portland’s Bureau of Environmental Services, summed it up well by saying.

“The benefit of an eco-roof is that it provides habitat for various species that are losing that kind of habitat in most urban environments around the world.”

-Brian Phelps






Olympic Sized Green Roof

17 02 2010

Courtesy Vancouver Convention Centre website

The winter Olympics just kicked off with the opening ceremonies from BC Place Stadium in Vancouver. But serving as the International Broadcasting hub for the games is the Vancouver Convention Centre — the world’s first LEED Canada Platinum rated convention building. The 1.2 million SF center boasts a 6-acre green roof, which also now makes it the largest green roof in North America.

The roof is planted with over 400,000 native plants and collects rainwater for irrigation which contributes to the buildings stormwater credits as well. Other interesting sustainable features include marine and shoreline habitat restoration. Fish habitat was actually built into the buildings foundations. The building also uses seawater for heating and cooling and incorporates on-site water treatment.

The following video “Vancouver’s 6 Acre Living Green Roof”, posted on You Tube gives a great sense of the scale and context of the green roof. The landscape architect who worked on the project, Bruce Hemstock, discusses the plants used, soil media and the idea behind habitat linking into urban centers that is beginning to be made possible with the inclusion of more green roof in our cities. Interestingly enough he says one of the biggest challenges of the project was initially convincing people that it was the right thing to do.





Toronto’s Green Roof Requirements Take Effect Monday

29 01 2010

Downtown Toronto
Photo Credit: istockphoto.com/benedek

On Monday, Toronto’s ambitious
green roof standards will go into effect. Any roof of a building over 2,000m2 will be required to include a green roof for a portion of the building. High-rise tower roofs that are 750m2 or less are exempt. The following is the breakdown of the required percentages of the roof area based on its size:

  • 2,000m2(21,528sf*) to 4,999m2 (53,809sf*) = 20%
  • 5,000m2 (53,810sf*) to 9,999m2 (107,629sf*) = 30%
  • 10,000m2 (107,630sf*) to 14,999m2 (161,449sf*) = 40%
  • 15,000m2 (161,450sf*) to 19,999m2(215,269sf*) = 50%
  • 20,000m2(215,270sf*) or greater = 60%

*square footage calculations are approximate

These standards will initially cover all building types with the exception of industrial. Industrial building requirements will take effect in 2011. To put these standards into context, the 20% requirements would include a typical modern office building to a medium size neighborhood grocery to a smaller big box store. Most stand alone restaurants and smaller residential projects would likely not meet the threshold to require a green roof. The other requirement levels would cover larger big box and larger grocery stores, significant retail centers, and industrial/warehouse facilities.

Interestingly, the available roof area that is used to calculate the requirements excludes areas designated for renewable energy, private terraces, and residential amenity areas (to a maximum of 2m2/21sf per unit).

The City’s eco-roof incentives program that provides $50/per m2 up to a maximum of $100,000 is still in place. According to their website, applications are being accepted starting March 1st. The deadline is April 1st. Award projects will be decided on April 16th.

This initiative is being launched in conjunction with the City’s new Green Standards Program. It reminds me of the United States Green Building Council’s (USGBC) LEED checklist. The program includes three categories, each having their own but similar requirements. The categories include low-rise non-residential, low-rise residential, and mid-high Rise (any use).

Additionally, the new standards do encourage green infrastructure requirements such as:

  • Retain stormwater on-site to the same level of annual volume of overland runoff allowable under pre-development conditions and retain at least the first 5 mm from each rainfall through rainwater reuse, onsite infiltration, and evapo-transpiration or ensure that the maximum allowable annual runoff volume from the development site is no more than 50% of the total average annual rainfall depth
  • Remove 80% of total suspended solids (TSS) on an annual loading basis from all runoff leaving the site based on the post- development level of imperviousness. Control amount of E. Coli directly entering Lake Ontario and waterfront areas as identified in the Wet Weather Flow Management Guidelines

Due to the legal ramifications of a continually evolving third-party system like LEED, we will likely see more city -specific green building programs being developed over the coming decade as cities seek to separate themselves and focus on the particular aspects of sustainable design that have the largest impact in their community.

You can find all of the standards on the City’s website here.

-Brian Phelps





Video Tour of ASLA’s Green Roof

4 01 2010

Back in October 2009 in our post “Green Roofs Address D.C.’s Environmental Problems”, we covered the research the American Society of Landscape Architects was doing with the green roof on its National headquarters and the many benefits it provides. I recently came across this well produced video tour of ASLA’s green roof (see below). It does a wonderful job of showing off the space and the diverse habitat that has been created. I particularly love the areas that use the steel grating to span some of the green roof areas. Enjoy.