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.





A NEW MEANING TO THE COLLEGE “GREEN”

18 12 2009

Green Roof Dashboard
from Davis Center at University of Vermont

With a son who is a sophomore in college and a daughter as a high school senior, I have managed to spend a lot of time visiting college campuses over the past few years. One of the things that I have paid particular attention to (and seen an huge increase in during the past two years) is the focus on sustainability. My strong hunch is that schools are incorporating sustainable technologies because this generation of smart, college age youth demand it.

Many college campuses now sport LEED certification on at least one building – my son’s dorm at the University of Richmond (Lakeview Hall) is LEED registered and undergoing certification. It is one of nine buildings at the University which is either certified, or in process of being certified as LEED with the USGBC. Locally, Vanderbilt University completed the LEED certified The Commons at Vanderbilt residential housing complex in 2008. As I have traversed the country and seen what must be dozens of (mostly) smaller liberal arts colleges, I have seen organic gardens and solar panels at Whitman College, windmills and biomass generators at Middlebury, local and organic foods at Skidmore, a unique “homestead” intentional environmental community at Denison, beautiful rain gardens at Emory and the list goes on.

I also found a interesting resource online called the College Sustainability Report Card for 2010 (www.greenreportcard.org), This report card basically looks at environmental sustainability at over 325 colleges and universities in the United States and Canada based on 48 indicators used to evaluate performance within four categories.

One of those categories is “green building”. It was heartening to see that 44% of the schools have had at least one LEED-certified green building or are in process of constructing one and a whopping three-quarters of all of the schools have adopted green building policies that specify minimum performance levels such as LEED certification for new construction.

I was particularly interested in taking a closer look at some of the successes that I have witnessed at several of the schools that I have visited especially as they relate to green infrastructure. I found some additional information on Emory, Allegheny, Middlebury, University of Vermont and Macalester.

WATER CONSERVATION

As a part of Emory University in Atlanta’s overall commitment to sustainability (with over 1 million square feet in LEED certified buildings), Emory has incorporated many innovative water-conservation technologies.. Particularly impressive to me was their implementation of rainwater harvesting and condensate recovery, especially in light of the fact that Atlanta suffered an historic drought event in the summer of 2007. On Emory’s whole campus they have to date included 6 cisterns with a collective size of over 350,000 gallons for both toilet flushing and for irrigation as well as a condensate recovery technology for over 4 million gallons of water per year.

In their new freshman residence complex including Ignatius Few Hall and Lettie Pate Whitehead Evans Hall, rainwater and condensate collection is diverted to an 89,000 gallon reservoir underground which can provide adequate volume to provide 2170 gallons per day needed to flush all toilets int eh buildings. The rainwater is collected form the roof, then filtered and slowed through a bioswale system outsde of the building and then into the below grade cistern. The condensate harvest provides a reliable source of water to supplement rainfall during those months from May through September. It is estimated that the condensate harvests is adding 300,000 gallons per year to the system.

At the nearby Whitehead Biomedical Research Facility Building, completed in 2001, the engineers devised a system of piping condensate back into nearby cooling towers to use as make-up water. This system conserves water AND diverts 2.5 million (that’s 2,500,000) gallons a year from the sanitary sewer system.

Video About Emory University’s Sustainability Efforts

GREEN ROOFS

It seems to me that many, many schools are incorporating green roofs as that technology provides one of the most visible elements to show-off sustainable design. In every school we visited, if there WAS a green roof, it was highlighted on the student led campus tours. The green roof were touted for their well-documented benefits such as longer roof life, reduced cost of heating and cooling, stormwater runoff reduction and habitat.

Allegheny College in Meadville, Pennsylvania impressed me with the well designed green roof on the Vukovich Center for Communication Arts. It is located within the topography of the campus site allowing for a fully accessible roof (entering the building at the green roof on the high side and entering on a lower level to the main campus commons or quad –type area. The roof includes extensive and semi-intensive depths and features lawn space as well as sedums and native grasses with an interesting incorporation of stones and cedar decking through the rooftop.

University of Vermont, just on the edge of downtown Burlington, Vermont, recently completed the 186,000 s.f. Dudley H. Davis Center. The Center features a 19,000 s.f. green roof.

Middlebury College, also in Vermont, provided a sloped green roof above the Atwater Dining Hall. I was interested in seeing their notation that in addition to the traditional green roof benefits that I have seen listed in may locations, Middlebury includes improved acoustical insulation, noting that green roof systems can reduce airborne sound levels by 40 to 50 decibels.

Macalester College in St. Paul, Minnesota impressed me, not in size but in determination. The two green roofs on campus were the result of student designs and even some student labor! The first green roof at Macalester was a 300 s.f. tray system installed above a walkway between tow residence halls and the newer 1350 s.f. green roof on Kagin Commons. I happened to be on campus the day the Kagin Commons green roof was unveiled.

I believe the influence of these campuses and so many others will influence the bright minds of our next generation of decision makers and leaders.





New Downtown High-rise Includes Green Roof

30 11 2009

The Pinnacle at Symphony Place, a 29-story office building in downtown Nashville, opened this month. The building includes 520,000sf of Class A office space. It is home to law offices of Bass Berry and Simms and the headquarters of Pinnacle Financial Partners. The building designed by the award winning architectural firm Pickard Chilton with Nashville architects EOA Architects is anticipated to receive LEED-Silver certification from the United States Green Building Council (USGBC). With the inclusion of a 28,000sf rooftop garden, the building contributes significantly to Nashville’s ever growing green infrastructure

The green roof, designed by our office, is located on the 7th floor above the parking garage and includes a series of spaces that can be enjoyed by the building’s tenants. The area is comprised of 9,400sf of pedestal pavers and 19,000sf of vegetated areas. One hundred percent (100%) of the pavers were selected to exceed the minimum solar reflectance standards established by the LEED rating system. The striping pattern continues the prominent vertical fins on the facade of the building into the rooftop garden area. The planting areas are a combination of extensive green roof (planting media depths ranging between 5-9”) and semi-intensive areas (planting media depths ranging between 18”-30”). The semi-intensive areas were planted to reflect a more traditional landscape around each of the gathering areas and provide areas for trees to shade and scale the spaces. In an effort to establish a more pedestrian scaled environment and additional interest a series of 12ft pyramidal trellis structures were incorporated in the extensive green roof areas.

It is estimated that the green roof can retain nearly 67% of the annual rainfall falling directly on it. In addition, it reduces the peak flows, is significantly cooler than neighboring conventional roofs, reduces thermal heat gains in the water that enters the stormwater system, and provides a beautiful space to look upon and enjoy.

We are honored to have been a part of such an exciting project and look forward to watching it grow. We have been pleasantly surprised by the significant growth the plant material has shown in a short time period. As it matures, we will keep you up to date on its progress.

-Brian Phelps





A Different Kind of Green Roof

4 11 2009

Research has begun on a light weight alternative to extensive green roofs (the least intense form of a green roof) for when structural loads or costs might otherwise deter a client from choosing to pursue a green roof. It is being referred to as a ‘green cloak’ and uses fast growing vine species that attach to a trellis suspended above the roof. Laura Schumann, a graduate student at the University of Maryland completed her thesis on the cost benefits for temperature and stormwater using green cloaks. More complete information on temperature and stormwater reduction can be found on the University’s website.

While green cloaks will likely never provide near the benefits of an actual green roof system, a major potential is that they are probably a less expensive option when installing a green roof is just too cost prohibitive and a client is still looking for a way to save on energy costs. In addition to reducing cooling costs and slowing the runoff of stormwater from roofs, one of the most intriguing facets may be the potential for using vine and trellis systems on sloped roofs where it is currently challenging to implement traditional green roof systems. Another aspect is that vines have the potential to provide cover for vertical surfaces and may help provide even greater temperature benefits when combined to cloak walls as well.

The vine species researched in the study included 5 different species: cross vine (Bignonia capreolata), kudzu (Pueraria lobata), Japanese Honeysuckle (Lonicera japonica), porcelain berry (Ampelopsis brevipedunculata), and Virginia creeper (Parthenocissus quinquefolia).

Virginia Creeper

Testing Virgina Creeper's effects on Building Temperature (Photo from Univerisity of Maryland's website)

One drawback may be that green cloaks might not be as aesthetically pleasing to the masses as green roofs and could be a hard sell for more refined urban or retail areas. And it may also be difficult to provide full coverage for large roofs, however even partial coverage could provide huge cost savings in cooling costs for big box retailers or manufacturer’s with large warehouses where load bearing capacities for roofs are low and aesthetics are not as much of a concern. Either way, this is another potential option available for designers to help reduce energy costs, the urban heat island, and reduce stormwater runoff.

– Sara Putney

GreenCloakTilley.ppt

Inspiration (photo from 'Green Cloak' Presentation, David R. Tilley, University of Maryland)