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Haven Kiers, MLA, LEED AP, GRP, is our Design Editor (2005).  She writes an occasional column entitled "Chic Sustainability," and co-writes and co-presents the "Top 10 List of Hot Trends in Greenroof & Greenwall Design" series with Linda Velazquez.  She feels the "Greenroof challenge lies in finding the right balance between idealistic principles and cutting edge design."

Haven is a Mom and lives and works in Davis, California, with her husband, daughter, and son.  Haven is a lecturer in landscape architecture at UC Davis and the special projects manager at the UC Davis Arboretum.   She has worked as a landscape architect, a city and environmental planner, and a consultant.  Haven designs and presents nationally about greenroofs and other green infrastructure, and is also a trainer for the Green Roofs for Healthy Cities Green Roof 101, 201, & 401 Courses.

Also see Archives of Haven and Linda's Chic Sustainability Watch Sky Gardens Blog posts.

email: haven (at)
View Haven's Profile

Chic Sustainability Column

Back to Nature ~An Alternative Approach to Planting Green Roofs

By Haven Kiers, Design Editor

Originally published in the Fall 2013 issue of Pacific Horticulture; reprinted with permission.

The prolific green roofs of Switzerland’s major cities meld even their most industrial edges with the surrounding landscape. Photo: Jeff Joslin.

If the phrase “green roof technology” calls to mind ice cube-like trays sandwiched between layers of plastic sheeting and synthetic fibrous mats topped with highly engineered growing medium, and a pre-grown sedum carpet you’re not alone.  This is an apt description of most American green roofs and the economic backbone of the contemporary green roof industry.  So this past summer when several Bay Area living architecture specialists were invited to travel and learn about green roof planting and policy in Switzerland, we thought we knew what to expect.

Instead, we were introduced to the polar opposite of what we had anticipated.  There were no systems, no plastic trays, no manufactured “moisture retention layers,” or synthetic filter fabrics.  The Swiss green roofs that we toured employed a simple layering of straw, or China reed (Miscanthus sinensis), topped with native soil from the site (sometimes mixed with lava rock or gravel), and planted with a wildflower seed mixture.  That’s it.

This project for a roofing company in Sins, Switzerland, is integrated with ponds, hydroponics, and solar technology, demonstrating the flexibility and potential synchronicity of such systems.
Photo: Jeff Joslin.

And these green roofs were spectacular!  They were nothing like the sedum-covered extensive roofs that look so much alike you can’t tell whether they’re from Boston or Berkeley.  One 100-year-old roof boasted 175 different species of flora, including 10 species of endangered orchids native to the wet meadow regions of Switzerland.  Another provided habitat for ground-nesting lapwings, a native bird population that has been decimated by foxes and urban growth at ground level.  And still others provided pollinator plants for local bees and butterflies.  The roofs were literally teeming with wildlife—from the tiniest spiders hidden in a nook of a rotten log to the sheep grazing on top of a small family farm building.

Swiss policy dictates that most new construction must include green roofs.  What is interesting is that the motivation for requiring green roofs in Switzerland has very little to do with energy savings, reduction of the urban heat island effect, or extending the life of the roof membrane.  Instead, the main driver is promoting biodiversity—typically an afterthought on North American green roof projects.  The Swiss understand the benefits of creating a lasting ecology on the roof by providing habitat for the plants and animals that will make it thrive.  Through basic principles of soil science and horticulture, they are employing effective technologies that allow roofs to develop their own ecosystems over time.

Planting on Zurich’s Sihlcity shopping mall roof. Photo: Jeff Joslin.

Here are a few of the lessons we brought back with us:

A green roof doesn’t need to have an expensive “system” in order to work effectively.

Swiss green roofs cost significantly less than their American counterparts, primarily because they don’t rely on manufactured systems that require you to purchase a variety of components regardless of the roof ’s particular needs.  None of the sites we visited used a plastic system to artificially create the layers of a green roof, and all them functioned perfectly well without it—including ones that had been around for over 100 years.  The roofs we saw were neither flashy nor expensive.  Instead, they incorporated straw or gravel for drainage—materials that are readily available, cheap, and work better to create a sustainable ecosystem on the roof.

Don’t let a “what if ” distract you from the “what can be.”

Local substrates are far more effective at creating healthy ecosystems
than engineered soils.

Integrating displaced soil from the site as a part of a roof ’s substrate helps recreate previously existing habitat.  Native soils can then be mixed with sand, lava rock, or loam in order to meet specific ecological needs on the roof.  Lightweight, engineered soils create sterile, harsh environments for microorganisms and insects.

Plant roofs with perennial and annual seeds and ephemerals that will thrive in the local climate.

We need to start observing our local ecologies and landscapes and incorporating these plant palettes into our roofs.  It is not necessary to install pre-grown green roof plants.  We can take the time to plant some seeds and see what works and what doesn’t.  The Swiss are patient.  They are willing to wait for a finished product and are not nearly as addicted to the principles of instant gratification as we Americans are.  We need to be willing to experiment and go beyond both the “natives only” and “sedum mat” dominating dogmas.

Logs and stones provide habitat niches for fauna on a green roof in St. Gallen.
Photo: Lisa Lee Benjamin.

Green roofs don’t have to be green.

If biodiversity is your main driver, plant coverage is not always the most important component of a green roof.  Open substrates provide habitat for nesting bees and other insects and can vary in height and depth.  Branches, logs, and rocks can provide visual interest while simultaneously improving habitat value on the roof with annual seeds providing short bursts of seasonal color.

A simple overflow system ensures drainage and water transfer between planted roof areas at the Sihlcity shopping mall in Zurich, Switzerland. Photo: Jeff Joslin.

There is nothing to be afraid of.

The North American green roof industry is built on fear.  Fear that the roof will leak and the building will collapse.  Fear that the plants will die.  Fear that the green roof will cost too much money.  The greater the fear, the more “mitigating” products can be sold.  If we just trust our informed instincts, we’ll be so much better off.  The reality is that as long as you have a solid underlying structure and a competent roof membrane, the rest doesn’t need to be complicated.  Don’t let a “what if ” distract you from the “what can be.”

Agricultural green roofs, like this one in Mohlin, provide additional area for crops and grazing.
Photo: Jeff Joslin.

Haven Kiers

Publisher's Note: See "Back to Nature ~ An Alternative Approach to Planting Green Roofs" in PDF from Pacific Horticulture Magazine.

Also see Archives of Haven and Linda's Chic Sustainability Watch Sky Gardens Blog posts.

A Look Back at the
2008 Top 10 Hot Trends in Greenroof Design Survey

By Haven Kiers, MLA, The Design Editor
January 17, 2009

Hello Greenroof Designers!

It’s time to start the New Year in green roofs with a look back at the one we just had.  Remember in the early days of 2008 when Linda and I asked you to tell us about the latest trends in green roofs in our Survey?  Well, we took the year to let them develop and grow and have now compiled them into a nifty summary of the past year’s biggest green roof trends. 

First off, here's a a review on "How do we decide the final Top 10 List of Hot Trends in Greenroof Design?" Essentially, we decide from our own design and editorial experience, exposure to the media, and from you, our readers!  How do we determine the number of projects in each category?  That one's easy - time constraints for presenting an albeit fast-paced PowerPoint in about 20 minutes.  In 2007 we were a bit over zealous and had 10 examples in each category (not to mention the intro), so for 2008 we limited ourselves to "just" six or seven to illustrate each trend.

As a recap, here are the final results from 2008: 2008
Hot Trends in Greenroof Design
Top 10 List:

10) Client Specific ‘Boutique’ Greenroofs

9) PreFab Modular Homes are Fabulous

8) Greenroofs as Art & Architecture

7) Parks & Interpretive Greenroof Spaces

6) Solar & Vegetative Roofs as High Performance Buildings

5) Greenroofs for Biodiversity

4) Institutional & Office Parks - Setting the Example

3) Eco-Communities & Eco-Cities

2) Sky High Cool Green Schools

1) The Influence of LEED on Design Professionals = Pushing the Green Envelope


Without further ado, here is a Summary of the 2008 Top 10 Hot Trends in Greenroof Design Survey (projects which were included in either our 2007 or 2008 Top 10 Hot Trends Lists are noted with the corresponding year):

1. What do you see as the current market drivers?

There were quite a number of market drivers propelling growth in the green roof industry in 2008, including everything from “major weather events” and “desperation” to “trendiness” and “aesthetics.”

Differences were most noted across countries, as Mathew Frith of Peabody Trust said, "In Britain it is now probably climate change, but also still with strong emphasis on biodiversity conservation (which has been the stimulus to renewed interest over the past 10 years)."  And while Dusty Gedge of agreed, adding, "In the UK biodiversity is still the big driver along with stormwater," Manfred Köhler of Hochschule Neubrandenburg believed client needs included the extremes of "sophisticated high end design - on the one other hand: the tree hugger, and the other, the urban gardener."

Overall, the two drivers that came up most frequently, however, were environmental sustainability (with an emphasis on stormwater management) and marketing. 

Chris Scott of GreenTech stated, "Environmentally conscious end users drive the demand for greenroofs," and Joe DiNorscia of Skyland USA, LLC feels "The tipping point has been reached in North America in terms of thinking about long term care of the environment and green roofs fit that mind-set."

It seems that the recent success of green roofs relies on these two interconnected notions – one, that green roofs are inherently good for the environment, and that two, because of this, their installation can increase the “green” credibility (and therefore marketability) of an organization.  It’s also interesting to note that “cost savings” were only mentioned by one survey respondent.  Apparently, the long term savings of a green roof still aren’t all that appealing or at least perceptible to most people.

Since there will always be a wide range of drivers and desires for green design, with as many innovative ways to incorporate them, this question demanded this category on the list: # 10) Client Specific ‘Boutique’ Greenroofs, which in fact will probably always hold this position as a catch-all for the truly unique projects of the world.

2. How important do you see the proliferation of LEED™ buildings as a market driver?

There is no question that LEED is an extremely important market driver for the green roof industry.  In fact, LEED responses were so popular that we placed it at the number 1 spot on the 2008 List with:

1) The Influence of LEED on Design Professionals = Pushing the Green Envelope

According to most respondents, LEED is “a huge driver,” “very, very important,” and “almost every LEED project has a green roof.”  One of the reasons for this is that many LEED buildings earn points for incorporating practices or materials that aren’t observably “green.”

However, green roofs provide a visual cue to people and let them know that they are looking at a “green building.”  As Dr. Bill Retzlaff, of G.R.E.E.N. at SIUE, stated, “A green roof makes a statement, gets LEED points, and is visible.”

Another benefit to the proliferation of LEED buildings is that people are beginning to realize that up-front investment is “more economical than cutting corners.”  Although LEED buildings (and green roofs) may cost more initially, they tend to pay for themselves and even save money down the line.

Yet let's not forget the human element, as eloquently expressed by reader Martha Shaw: "LEED buildings increase in importance when they champion the people living in them, just as architecture has always done when it takes a populist and humane step."

In any case, "The Influence of LEED" clearly deserved the number one spot as a category of its own, but there were numerous examples of LEED certified buildings throughout all of the Top 10 List.

3. What are the directions sweeping our design profession?  Why are we building greenroofs?

The answers to this question were all over the board and covered nearly every possible reason for building green roofs, from stormwater, heat island and cooling benefits to long term cost benefit analysis.  Here is just a sample of some of the responses:

“Wider acceptance of an overall impression that environmental degradation is real and can (must) be dealt with at the local level (one project at a time) to make a difference in the future,” Martin A. Haber, ASLA, Roy Ashley & Associates, Inc.

“Housing today -- and I live currently in suburbia -- has been revealed like the naked emperor as being ridiculously impractical in so many ways.  We need smarter designs that can cope with the future and yet allow us to comfortably thrive.”

"Growing in intensity is housing developments. This has the potential to dwarf any previous aspects of green roof benefits due to the shear scale and broad application.  Commercial green roofs, the current vast majority of examples, are usually located in developed areas - no clear cut forests, not overturned farm land.  Farm land and forested lands are the province of housing developments.  Increasingly these resources are becoming battle grounds, whether over water or habitat or a number of other concerns," Patrick Carey, hadj design.   This type of comment contributed to: # 3) Eco-Communities & Eco-Cities.

“Design professionals are becoming more focused internally on sustainable buildings, which means that the client is getting a more environmentally preferable building which can include greenroofs.”

“Homeowners are considering greenroofs because city dwellers need green space to recreate.  People also want to decrease their carbon footprint, especially when there are incentives to do so.”

“In terms of energy, there are some businesses that are facing spiraling costs and have needs that can not even be met by conventional buildings.  Internet Service Providers, for example, are finding conventional HVAC systems inadequate to keep their server rooms cool enough for good operational efficiency.”

"Greenroofs as a BMP for stormwater credit.  More incentives are necessary so builders and developers find it cost efficient to do greenroofs.  Money talks.  If it doesn't make the builder/developer money, he/she won't do it (generally)," Bill Brigham, ASLA, City of Atlanta.

And the simply flippant, "It's hip to have a green roof."

4. Which built innovative projects have informed clients and spurred additional market interest, and what types of greenroofs are clients now demanding?

It’s no surprise that many of the respondents chose either their own projects or projects that were locally accessible to them as the ones that have informed clients and spurred additional market interest.  Highlighted projects included the Minneapolis Public Library (2007), ASLA Headquarters in Washington, D.C. (2008), Millennium Park in Chicago (2007),  the Laban Dance Centre in Deptford, London (2007), the Ford Motor River Rouge Plant (2007) and Silvercup Studios in New York City.

Minneapolis Public Library, highlighted in 2007's
# 4) Government and Big Box Retailers as Big Environmentalists

ASLA Headquarters, highlighted in 2008's
# 4) Institutional & Office Parks - Setting the Example

Millennium Park, highlighted in 2007's
# 2) Bigger is Better – Mega Greenroofs

Laban Dance Centre, highlighted in 2007's
# 10) Unique Market Drivers: Boutique Greenroofs

Ford Motor River Rouge Plant, highlighted in 2007's
# 2) Bigger is Better – Mega Greenroofs

Silvercup Studios

As for the types of green roofs clients are now demanding – usable roof space, low maintenance and pre-planted dominated the results.

5. Which greenroof projects received the most press & why – and do you feel it was justified?  In other words, how important is media exposure?

The green roof media darlings were the ASLA Headquarters, (2008) above, the Clinton Memorial Library in Little Rock (2008), and the Sidwell Friends School in Washington, D.C. (maybe Obama will fall in love with green roofs now that his daughters attend).  Most respondents felt that any and all green roof press was justified.

Clinton Memorial Library, highlighted in 2008's
# 4) Institutional & Office Parks - Setting the Example

Sidwell Friends Middle School

Cindy Marso, of Ann Rieff Garden Design, put it best, “The more we hail these types of plantings and show the myriad benefits and the beauty to the general public, who will be able to resist?”

And according to Greg Long, of Capitol Greenroofs, LLC, the importance of media exposure cannot be overstated.  “I can not emphasize how important publicity is for the design community when promoting greenroofs.  On a couple of my projects, jurisdictions have even devoted a web site where people can view the roof through an on site camera.  It even seems like on some projects I have been asked to help with communication plans and press kits.”

6. What new plant types (grasses, for example) or design palette styles (Asian-inspired or native communities, for example) have you seen?

The big trend here is with native and rare plants that provide biodiversity.  As green roofs mature in the marketplace, so do the types of plants that are used.  More frequently, designers are shying away from the ubiquitous sedums towards regionally adapted plant palettes.  Projects like the California Academy of Sciences (2007) in San Francisco boast native wildflower mixes, and organizations like the Lady Bird Johnson Center (2008) have launched research programs to study the use of native plants on green roofs.

California Academy of Sciences, highlighted in 2007's
# 5) Physics-Defying & Cutting-Edge Applications

Lady Bird Johnson Center, highlighted in 2008's
# 7) Parks & Interpretive Greenroof Spaces

But fear not for the much maligned sedums!  These sturdy workhorses will always have a secure spot on a green roof.

7. Share some of the innovative technologies that you've seen incorporated into greenroofs.

Many of the innovative technologies our respondents described make use of stormwater runoff.  Examples include: greywater irrigation technologies, cisterns, and detention ponds and dry creek beds to capture roof water.  Respondents were also excited by new lighter weight growing medium mixtures and pre-vegetated modules that were light enough be used on retrofit projects.

For example, Nathalie Hallyn of The Kestrel Design Group, Inc. said, "Green roof projects with holistic design that maximizes function and aesthetics; e.g. green roofs that are planted with wetland plants to maximize evapotranspiration and building cooling; unique habitat features in urban areas where there is no space for them on the ground."

And Sarah Murphy of Canopy likes the idea of mixing high tech with low tech by using construction debris, such as old bricks, to create a patio on a green roof and then incorporating photovoltaics into the design as well.

8. Who are the influential and creative designers driving design and fostering growth, expression, or awareness?

We didn’t get an overwhelming response to this question.  Many respondents simply left it blank.  In fact, not one designer received more than a single vote.  Some of the answers included: Paul Kephart and Rana Creek, Stephen Brenneisen, Reid Coffman, Paul Mankiewicz, William McDonough, Steven Peck, Linda Velazquez, Ed Snodgrass, Perkins + Will, HOK, Fox + Fowle and universities such as the University of Georgia (UGA) and Penn State.

As one response succinctly stated, “Remarkably, the design community in my opinion isn't doing as much as they could to promote these systems...”

Should this be taken as a call to action?  Is it time for green roof designers to step up to the plate and make their voices heard?

9. Share with us what you consider “Visionary” Built Projects - why, where are they, and by whom?

Again, slim pickings.  People responded with the types of projects they would like to see, not necessarily ones that had already been built.

Here’s a taste of the reality and perception: “I feel that every greenroof is visionary in its own right because on every project you always have to find creative ways to fund the project and then during the design phase have to make critical decisions on what components and elements either remain in the design or get "value engineered" and removed from the job.  ‘Visionary’ projects come at such a cost that many clients could never afford such an undertaking.”

10. Share with us thoughts on Visionary Proposed Projects - why, where are they, and by whom?

There was a little talk about William McDonough’s proposal to grow rice on rooftops in China (2007), but beyond that, this group of respondents is not impressed with any proposed or conceptual projects.

Rooftop Rice Paddies, Liuzhou, China (Conceptual); Architect: William McDonough + Partners, highlighted in 2007 in the # 1) Visionary Proposed Projects category.

11. If you had to just name one, do you have one favorite greenroof project overall, as well as just one from 2007 – and a quick why?

The "quick why" was quick indeed, usually described with a one-word adjective including: meaningful, stunning, important, experimental.  Notice how many of these fall into the "institutional" category - it would seem people are looking for leaders on a grand scale.  Readers didn't differentiate their preferences by year, but the contenders were:

Clinton Memorial Library, Little Rock, AR (2008) see above, in # 4) Institutional & Office Parks - Setting the Example.

Zurich Central Railway Station, Zurich, Switzerland.  We had too many examples of biodiversity already in this category, especially from über-biodiversity-friendly Switzerland.

North Park 500, Atlanta, GA.  Our Institutional & Office Parks category was full here, too.

Ballard Library, Seattle, WA (2008) in # 4) Institutional & Office Parks - Setting the Example.

Church of Jesus Christ of Latter-Day Saints Conference Center, Salt Lake City, UT (2008) in # 4) Institutional & Office Parks - Setting the Example.

Ballard Library, highlighted in 2008's
# 4) Institutional & Office Parks - Setting the Example

Church of Jesus Christ of Latter-Day Saints Conference Center, in 2008's # 4) Institutional & Office Parks - Setting the Example

ACROS Fukuoka Prefectural International Hall, Fukuoka, Japan (2007).  "Asian Crossroads Over the Sea" was highlighted in 2007 in # 8) Living Roofs and Living Walls = a Living Skin for Green Buildings.

328 Euclid, Toronto, Canada.  328 Euclid was highlighted in 2007 in # 3) Cool Green Residences: Organic Integration of Mind, Body & Soul.

ACROS Fukuoka Prefectural International Hall, highlighted in 2007's # 8) Living Roofs and Living Walls =
a Living Skin for Green Buildings

328 Euclid, highlighted in 2007's
# 3) Cool Green Residences:
Organic Integration of Mind, Body & Soul


The Stunning School of Art, Design and Media at Nanyang Technological University , in 2008's
# 2)
Sky High Cool Green Schools

School of Art, Design and Media at Nanyang Technological University, Singapore (2008) - although this project could have represented # 8) Greenroofs as Art & Architecture, we placed it in # 2) Sky High Cool Green Schools.

The Top 10 List Itself

At the end of the survey, we also asked respondents to review and edit our preliminary, Working List that we had been compiling since mid-2007, which initially was:

10) Client-Specific Boutique Greenroofs
9) Do-It-Yourself Greenroofs
8) Pre-Fab Modular Homes are Fabulous
7) Greenroofs as Art and Architecture
6) Parks, Zoos & Botanical Gardens - Outdoor Living & Research
5) Solar and Vegetative Roofs as High Performance Buildings
4) Museum and Corporate Greenroofs - Setting the Example
3) Luxury Green Homes, Eco-Communities & Eco-Cities
2) Cool Green Schools of Higher Education
1) The Influence of LEED on Government and Design Professionals

Only a handful of people suggested position changes or new categories altogether, in particular from Mathew Frith, who contributed this list:

10) Greenroofs as Art and Architecture
9) Do-It-Yourself Greenroofs
8) Code for Sustainable Homes; what can green roofs do to assist in meeting this?
7) The Influence of LEED on Government and Design Professionals
6) Solar and Vegetative Roofs as High Performance Buildings
5) UK-based green roof research to meet demands of policy-makers
4) Client-Specific Roof gardens (boutique and otherwise!) for luxury residences
3) Green roofs to meet the impacts of climate change
2) Development of green roof policies in regional planning
1) Green roofs for biodiversity

In addition to Mathew's list above, the one standout from everyone's overall input was that we had to include biodiversity as its own trend, resulting in 2008's # 5) Greenroofs for Biodiversity.

Our initial # 9) from the Working List, "Do-It-Yourself Greenroofs," while an ever-increasing trend among homeowners, simply didn't have enough momentum yet so we included examples in # 10) Client Specific ‘Boutique’ Greenroofs.  Another reworked category was # 4) Museum and Corporate Greenroofs - Setting the Example, just a bit too restrictive, which morphed into 4) Institutional & Office Parks - Setting the Example.

One particularly funny Brit's comments followed these categories, which he obviously didn't care for: # 10) Client-Specific Boutique Greenroofs, # 8) Pre-Fab Modular Homes are Fabulous, and # 7) Greenroofs as Art and Architecture:  "urghhhhhhhhhh."

So what does this all mean?

It’s clear that the green roof industry is growing and that there are a number of market drivers propelling it forward.  The main aspect that seems to be missing (and made apparent though the results of this survey) is a strong and purposeful sense of design in green roofs.

Clearly, we need visionary projects.  And we won’t have visionary projects within visionary leaders to design them.  The last thing we want is for green roofs to fall by the wayside because a downturn in the economy is making them less attractive.  The way to save green roofs is to build their visual and aesthetic appeal.

Any thoughts on what 2009 will bring to the industry?  Should we send out another survey?  What questions would You like to see asked?  Send us your perspectives by January 31, 2009 and we'll compile some more questions for you to contribute to the 2009 Top 10 List of Hot Trends in Greenroof Design.

Now get out there and design!!!

~ Haven Kiers
The Design Editor

Publisher's Note:
  Haven't seen the actual paper from 2008?  Download the lengthy PDF THE 2008 TOP 10 HOT TRENDS IN GREENROOF DESIGN by Linda S. Velazquez, ASLA Associate, LEED AP, Publisher/Editor & Design Consultant and Haven Kiers, MLA, Design Editor & Design Consultant.

Click to see the Lists and PowerPoints for either the 2008 or 2007 Top 10 List of Hot Trends in Greenroof Design.

Chic Sustainability
A Look Back at the
Hot Trends in Greenroof Design for 2007

By Linda S. Velazquez and Haven Kiers

Last May, Publisher Linda Velazquez and Design Editor Haven Kiers presented a lively and fast-paced session of the hottest avant-garde greenroofs around at the 5th Annual Greening Rooftops for Sustainable Communities Conference, Awards & Trade Show in Minneapolis, Minnesota.  Our completely subjective choices were based on our exposure and opinions in the greenroof world here on and from a multitude of multimedia including architecture and design magazines, news articles, websites, blogs, radio interviews, TV shows, you name it!

Revisiting our Top 10 List and these project vignettes is a great way to have a little fun and hopefully jumpstart everyone's creative juices for the new year.  These are both new and rediscovered projects that we can draw inspiration from, talk about, delight in, and emulate in 2008 and beyond.  To learn more about each project, click the hyperlink and see the complete profile in The Greenroof Projects Database.

We are presenting our updated original paper here from the Design Track, Session 2.4: Innovative Uses of Green Roofs along with new photos and projects from our actual PowerPoint presentation from the Minneapolis conference.  It's hard to be cutting edge and avant-garde with the latest design trends when the paper is due months before the conference!  By presentation time we had added and edited projects according to new information hot off the presses.

Look for our second installment, aptly titled "The 2008 Top 10 Hot Trends in Greenroof Design," at next year's Greening Rooftops for Sustainable Communities Conference, Awards & Trade Show in Baltimore, MD.  And new this time around will be our Greenroof Design Trends Survey ~ we want your opinions on what you consider to be the latest greenroof trends.  What projects do you consider noteworthy, pushing design limits, sexy, awesome?  What living roof applications are no longer just unique but you see becoming actual trends within the market and industry?  Who are the designers to keep an eye on?

Participate in our 2008 Greenroof Design Trends Survey, now available online.  We expect to hear back from you!


Greenroofs are constantly touted for their ecological benefits but rarely for their contribution to the current architectural vernacular. This inaugural yearly list will look beyond the function of greenroofs and instead focus on the top 10 hottest architectural trends in vegetated rooftop design.

Greenroofs deliver much more to the urban landscape than just the obvious ecological, economic and aesthetic attributes of stormwater management, temperature and energy reduction, and provision of additional green space. Why do clients want a greenroof? Should a greenroof be defined solely by its function as an ecological cover? Can greenroofs also be sexy and outrageous? Are they the next big design trend in architecture? How are designers pushing the limits? These are the questions that underpin our collection of innovative projects and market drivers from across the globe.

We offer a fast-paced Top 10 List of vignettes that thrum with oppositions of our established perceptions and experience, highlighting out-of-the ordinary applications, specialty designs and even bizarre projects on the boards. Looking beyond stormwater and heat islands, we'll explore plans for innovative recreation, including a rooftop ski slope in Delft, the Netherlands, and a converted helipad-turned-temporary grass tennis court 692 feet in the air in Dubai. We’ll look at less typical greenroof market drivers, such as a 670 SF doggie greenspace for a 10-year old, 9-pound Yorkie and a rooftop garden with plants from the Bible as a teaching laboratory for ministers. See a native desert greenroof in the American southwest and an old fashioned front porch perched on a greenroof in the middle of Manhattan, complete with squeaky screen door and a rocking chair. Explore greenroofs that defy expectations of sedum and wildflower meadows and instead integrate sleek and sexy vegetation with the building form. Proposed projects we'll delve into include plans for rice paddies on rooftop farms in China and the 2010 Vancouver Olympic Village with 50% greenroof coverage...

The Top 10 List of Hot Greenroof Design Trends for 2007:

10) Unique Market Drivers: Boutique Greenroofs

9) Sports & Recreation in Unexpected Places

8) Living Roofs and Living Walls = a Living Skin for Green Buildings

7) Eco Resorts, Hotels & Therapeutic Gardens

6) Food on the Roof: Skyrise Urban Ag

5) Physics-Defying & Cutting-Edge Applications

4) Government and Big Box Retailers as Big Environmentalists

3) Cool Green Residences: Organic Integration of Mind, Body & Soul

2) Bigger is Better – Mega Greenroofs

1) Visionary Proposed Projects

Favorites not on “The List”
On a lighter note, and before we get to the real thing, here are some categories and projects that for one reason or another just couldn’t cut it for our 2007 Top 10 List. But we’re going to show them, just for fun…

A new organic way to green the skyline: The “Green Gherkin,” Inhabitat's April Fool’s ‘07 Inspiration – CHIA vegetated wall and roof panels?
Too bad it’s not real!

Greenroof Transportation?  Leave it up to the Swiss! Interestingly, the company advertised is a medicinal herb company. Photo Courtesy:
Rob Berghage from Penn State.

Fashion & Décor:  What to wear at your next green party from Inhabitat…And how to dress your tablescape and surroundings for green chic sustainability and success, too!

And our favorite fantasy living roof of all time not on “The List” is...Edible Residential Greenroofs in Middle Earth: Unfortunately, Hobbits were not eligible this year, but were encouraged to try again…

And now without further ado, back to the real thing - download the complete PDF:


Chic Sustainability
Inaugural Column, October 2005

Green, Chic, and Sexy - And Good for You, Too!

By Haven Kiers
All Photos Courtesy Haven Kiers unless otherwise noted.

Let’s face it. The current mental image most Americans have of green roofs is one of scraggly overgrown plants that turn brown in the winter and make the house below look messy and poorly maintained. In most minds, a green roof is for hippies who want to save the world. It belongs in places like Berkeley, atop a straw bale house half buried in the earth with solar panels lining the driveway. Unfortunately, the green roof industry hasn’t done much to try and change that perception. Rather than actively working to package the green roof as the latest innovation in design, the green roof industry has instead been focusing on how good it is for the public (environmentally, economically, and educationally). And as we all know, no one wants to invest in something simply because it is good for them.

The challenge, therefore, lies in finding the right balance between idealistic principles and cutting edge design. My goal is to try to present the green roof as something sleek, chic, and sexy, without sacrificing its social and environmental appeal. I want to give green roofs the attention and fanfare they rightly deserve from people that otherwise wouldn’t give them a second glance.

Grasses and succulents reflecting the Frasier River beyond

Photovoltaics, colorful wind turbines, and a greenroof

Left: Vancouver Public Library in Vancouver, B.C., Canada; Photo Source: Landscape Architecture Magazine of 5.98;  Right: BedZED in London, England; Photo Source: Beddington Zero Emission Development

For this first column, I’m going to highlight a mixture of green roofs that don’t fall into the typical mold. Let’s start by looking at a few green roofs that make use of color as a means of expression. In Bordeaux, France, architects planted the entire roof expanse of an air traffic control center with rows of lavender. The intense purple is a stark contrast against the gray tarmac and concrete of the runway system (I should know; I snuck through the security booth to get a gander at it!). Not only does it stand out as a beacon for pilots looking to land, but it also provides a sense of regionalism.

At the Vancouver Public Library, in Vancouver, B.C., Cornelia Oberlander used cool colors to create serpentine bands of contrasting grasses that provide visual relief for office workers above. Architect Bill Dunster followed a different tact for the BedZED - Beddington Zero Emission Development (an environmentally-friendly, energy-efficient mix of affordable housing and work space in Beddington, Sutton, England), combining brightly painted vents with cobalt blue photovoltaics and a rainbow hued mat of sedums to create an explosion of color on the rooftop.

Photo Courtesy Haven Kiers

Photo Courtesy Haven Kiers

Left: The Palais Omnisports de Paris-Bercy in France;
Right: Mowing the Roof.

Construction of green roofs has come a long way from the leaky earth sheltered homes of the seventies. In Paris, France, architects Andrault, Pavat, Prouvé, and Guvan used a stepped system of plastic grids to contain panels of turf across the 45 degree slope of the Palais Omnisports de Paris-Bercy. The close-cropped grass of the pyramidal building seemingly defies the laws of gravity and begs the question, “How do they mow that lawn?” Luckily, I happened to be visiting the site on a day when they were mowing and saw the technology in action: a cable and pulley system rigged to a standard push lawnmower does the job.

Vertical supports, above and below; Photos by Haven Kiers

In Southern France, architects Jourda and Perraudin created one of the world’s suspended green roofs, an 8,000-square meter umbrella-like roof, hanging from poles like a circus tent. Blanketed with a mixture of wildflowers and grasses, the roof of this international school in Lyon creates a giant canopy for the classrooms below. I visited this site during a week when school was not in session and so was unable to go inside and really experience the building. Still, just being able to see the immense poles required to support the roof up close was pretty spectacular.

One of the world’s suspended greenroofs in Lyons, France.*  Photo above by Haven Kiers;
Photo below Source:  Green Roofs & Earth Sheltered Buildings

While some green roofs rely on color or technology to intrigue and attract, others depend on form and space. At the main terminal of the Schiphol Airport in Amsterdam, sedum covered glass pyramids seem to explode from the roof, peeling back the structure of the building and revealing windows into the bustle of the terminal below. Like most airport terminals, the structure consists of two levels, a level below for departing passengers and a level above for arriving passengers. Entering taxis and cars on the second level are therefore afforded an eye-level view of the green roof (as a departing passenger, the roof is a little trickier to find; I had to take an elevator all the way to the top of a neighboring hotel before I realized that I had been under it all along!).

Amsterdam International Airport Schiphol Plaza Greenroof

The proposed Renzo Piano redesign of the California Academy of Science in San Francisco’s Golden Gate Park creates a roof of mounds and valleys that dip and rise in various heights and sizes, creating pockets of shade and opening vistas into the parkland beyond. The building is supposed to be completed by 2008, and I, for one, can’t wait to see it. Visitors will be able to climb up onto a viewing platform and study the roof’s topography up close.

Proposed Renzo Piano Redesign of the California Academy of Science

Redesign of the California Academy of Science in San Francisco’s Golden Gate Park; Graphics: California Academy of Sciences

Many environmentally-friendly technologies here

But not all green roofs need to be chic and modern to capture attention. In less urban settings, green roofs can help blend structures in with their natural surroundings. The architect Peter Zumthor used the setting of the Swiss Alps to its best advantage by seemingly merging his thermal baths into its slopes.

Architecture by Peter Zumthor; Photo by Haven Kiers

Thermal baths below a greenroof

Peter Zumthor's naturalistic approach in the Swiss Alps.

The turfed roof becomes a natural extension of the grassy hillsides above it, and the local quartzite and concrete building juts out like a rock embedded in a quarry. So complete is the blending of architectural structure and landscape that the sight of goats grazing on the roof does not seem out of context. If there is one green roof that I recommend going to visit, this is it!

Winterscape of the thermal bath greenroof

Goats welcome!

Sloped greenroof echoes hillsides

Goats, grassy hillsides, and grassy greenroofs blend together in Switzerland with ecological beauty.

Let me conclude by reiterating the main premise of this column: The fact that green roofs are environmentally friendly does not preclude them from being aesthetically appealing.

Japanese architect Terunobu Fujimori says it best:

"We often see plants on roofs of modern buildings, but they hardly ever blend in with the architecture. This is because rooftop gardens are usually designed by ecologists, who dislike artificial things. They would rather suppress the artificial to better express the plants. But I think both the plants and the building have to look good. It's not easy, but I want them to get along well."

~ Haven Kiers
The Design Editor

* Reader Email From: Philosophically Understated in Stuttgart
Sent: Tuesday, March 14, 2006 6:57 AM

Subject: The world's only suspended greenroof in Lyons, France

Dear Writers,

Just Another Suspended Greenroof in the World!

Photo Source and Credit: Jörg Breuning, Green Roof Service LLC.

I really enjoy reading the articles, especially when people aren't quite correct.  The "world’s only suspended greenroof in Lyons, France," for example, is actually a rather typical roofing method here in Europe.  Here in Stuttgart, Germany, we have a 130,000 sf suspended greenroof, see above.  I believe it was built in 1995 or earlier.  On this particular project I have been up on the roof only once and I took this picture in August, 2005, from a spot where you can see many other greenroofs.  As a local you know all the good places to go within a city :) and when I offer greenroof tours this isn't a place where I go (because you have to walk 30 min. and most guests are not used to that).

This suspended greenroof is an extra heavy system to keep the roof down during heavy storms because underneath it is open space, as parking lots for buses.  The building is owned by the public transportation company and they have at least 2,000,000 sf of greenroofs on all their buildings together in Stuttgart.  I will find out more when I am in Germany in mid July - mid August.

I know that Americans like all the superlatives while the Germans prefer the understatement.

When talking about greenroofs the word "only" sounds good but most likely you will find that it has been done before; usually "new" designs have already happened elsewhere, although it may be hard to believe.  Suspended roof construction with or without greenroof is a common technique in Germany or at least in Stuttgart.  Maybe you have seen a photo of the DaimlerChrysler V6/V8 engine plant?  On this project they combined this roof technique with a kind of traditional factory design.

Prof. Jörg Schlaich (70 years old) and his former teacher Fritz Leonhardt started out with all kinds of suspended construction (actually both are from Stuttgart).  With projects all over the world (many prototypes in Stuttgart) they have taught this technique to many, many people all over the world, too.

Basically I wanted to say that in Stuttgart many things are just accepted as normal, although they may be celebrated every year somewhere else (whether it was the place where the first car was built - Gottlieb Daimler, Porsche = VW Beetle, Robert Bosch, etc.).  As I said, perhaps it is the simply the philosophy of German understatement of the people, or it could be the lack of marketing skills - who knows?

Regards, Philosophically Understated in Stuttgart

Publisher's Note:  I did change the captions on Haven's Lyons greenroof just a bit to reflect this fact.

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