GPW: The American Society of Landscape Architects (ASLA) Headquarters

May 7, 2010 at 1:16 am

The American Society of Landscape Architects (ASLA) Headquarters  in Washington, D.C. was our Greenroof Project of the Week (GPW)  from April 25 through last Sunday, May 2, 2010.   When I asked  ASLA  for some updates on the roof, they explained they were in the midst of midyear meetings, so I knew I would be a bit late reporting on this beautiful rooftop space, but here we go!   I chose this particular project to end April, aptly befitting since it was Landscape Architecture Month.   Founded in 1899, ASLA chose April  because it is the birth month of the “Father of Landscape Architecture,” Frederick Law Olmsted, and in any case it’s certainly a perfect  example of thoughtful, sustainable design to end Earth Month on a positive note, too.

Being an associate member of ASLA (I’m not full ASLA because although I have a degree in landscape architecture, I’m not licensed as a landscape architect –  aka LA), I was very proud that our professional organization became a greenroofing pioneer when they decided to retrofit their headquarters with a living roof back in 2004.   Under the leadership of landscape arcitechture firm Michael Van Valkenburgh Associates, Inc.  (MVVA) and in typical LA fashion, a creative, design-focused team of practitioners was  established to determine functionality and design intent with all the stakeholders. Multiple charrettes  afforded an open invitation to collaborative feedback and re-design.   One of the main priorities was for the roof to provide educational, viewing,  and recreational opportunities to employees and visitors – in effect, a landmark demonstration project to showcase the many benefits of greenroofs and  what landscape architects contribute to this project type.

Since weight was a potential  issue on the older building as well as accessibility, the project began with a structural assessment to ensure that the roof could accommodate the additional load of a greenroof, around 40 lbs/sf for an extensive roof.   Limitations became opportunities for creative design:

“The designers made maximum use of the structural capacity of the building, varying soil depths and plantings to take advantage of differing load capacities. For example, the elevator shaft has the greatest structural capacity and could accommodate 21 inches of soil; plantings on the elevator shaft include sumac trees, which may grow as tall as 30 feet at maturity.” ~ ASLA Green Roof Demonstration Project Fact Sheet

The ASLA greenroof is unique in so many ways!   As stewards of the Earth,  landscape architects promote native plants, which always positions a plantscape – whether on land or roof – to  accurately portray  its genius loci, or sense of place.   And yet as we all know, greenroofs most certainly are not set in native environments – the “soil” is not native as it is a highly engineered growing medium designed to  supply drainage and retain moisture, secure and anchor plant roots,  and provide aeration and nutrients in a highly unnatural environment – a rooftop usually separated from the ground plane by many feet.

 

Balancing this responsibility, ASLA decided to inform the public regarding  both options and the roof contains both native and introduced plant species – the more proven,  non-native greenroof  plant material, which for the most part has been the true survivors of the harsh effects of wind, frost, heat, and drought found on a roof, and various native selections researched to perform well under this stressful conditions.   Here’s a look at the changing aesthetics of nature, even on designed spaces – the two  photos  above show the South Wave in bloom: the top photo is from early May, 2007, and the bottom from June, 2009, which sports its current look.

[The] “desire to make the green roof feel like a garden also guided MVVA’s approach to planting the space. The idea was to use the roof as a kind of laboratory for identifying species, beyond the typical green roof sedums, that could thrive in shallow soil, and under the harsh environmental conditions typical of many urban rooftops, without extensive maintenance or watering.   We were particularly interested in plants that might offer increased environmental and experiential value.

“In addition to a variety of succulents, therefore, the plantings included flowering perennials like Goldenrod, Spiderwort, Black-eyed Susans, Artemesia, and Butterfly Milkweed, as well as a variety of grasses, including Blue Gamma Grass, and Virginia Wild Rye.   For the first two years during the establishment of the plants, we had a member of our staff make periodic visits to evaluate the success of the planting, making adjustments to the plans based on our observations.” ~ Michael Van Valkenburgh Associates, Inc.

So their design features two different but equally stunning elevated  “waves” featuring a 6″ deep semi-extensive system with both native (flowering herbaceous perennials and grasses) and non-native plants on the North Wave, 6′ high,  and non-native plants (mostly sedums)  on the 4.5″ deep  extensive South Wave system, 5′ high.    From the central viewing platform, plants are brought up to eye level and an aluminum grating was added so sedum is literally blooming at  visitors’ feet from another extensive greenroof system underneath.

The waves  also act as  noise insulators from the a/c units and the roof provides an urban habitat for birds, pollinating insects and butterflies.   Completed in 2006 and open to the public almost  five years now, visitors have come from around the world to view the 3,000 sf greenroof, including past First Lady Laura Bush.

MMVA provided the axonometric drawing (thumbnail) at left of the various layers of the greenroof which  shows how the design uses typical green roof materials, but in a way that is layered and exaggerated to create a space that is visually engaging and multi-functional (originally posted in the April, 2006 USATODAY.com article “Green roofs swing temperatures in urban jungles” by April Holladay  under “Anatomy of a Green Roof“).    Rachel Gleeson, Senior Associate with MVVA, explains that the  spatial innovation of the design is an extreme vertical exaggeration of the roof insulation (Styrofoam) to create the two large sloping landforms that are the “waves,” rising to heights up to six feet.   Covered with only a thin soil profile, they create a rare kind of rooftop topography that has a profound influence on the space.

 

Yet the waves posed technical challenges.  After the application of the Styrofoam, a perforated soil retention membrane was added to allow water to stream through but still   hold the plants in place.   A cable was then run through the system to prevent it from becoming airborne.   Rachel continues:   “Strong winds on the small roof threatened to shear the lightweight foam from its anchors, and the shape and angle of the landforms’ walls compounded this threat. Robert Sillman Associates, the structural engineer on the project, devised an ingenious solution that used the arcing steel frames of the landforms as armature.    [The cable] elegantly secures the two foam objects to the roof trusses below, preventing the foam from blowing off the building.”

“One of the things that MVVA felt was important with the ASLA Green Roof was to establish a precedent for a hybrid green roof garden that celebrated the unique pleasure of an urban rooftop garden without sacrificing the utility and low weight of a typical green roof.   Some of the most exciting aspects of the ASLA Green Roof are the ones that demonstrate ways that the human uses and the green roof functions could really support each other – most notably the “waves” of raised planting and also the grating that allowed for open walking surfaces above planted areas.” ~ MVVA

 

Each wave is distinct and beautiful at different times of the year and serves double-duty by not only offering all of the ecological, environmental, aesthetic and psychological benefits pertaining to greenroofing, but showing the public options for creating a living roof of their own.   And the innovative metal grating walkway system over the middle greenroof plantings allowed ASLA to utilize 90% of the greenroof by planting sedum and other succulents below the grates!  

“For the most part, sedum and green roof plants cannot be walked on, which often times creates a trade-off between having a green roof and creating an occupiable space for people.   The experimental system used in the ASLA Green Roof floats a super lightweight aluminum grating, low in heat conductivity, 3″ over a thin green roof system of sedum.   The sedum selected usually reaches about 6″ in height, so the plants are not hidden, but can poke up through the aluminum grating a bit.   In the areas of high traffic the plants that emerge through the grate get trampled a little, but this results in regeneration, rather than destruction.” (MVVA)

One more  unique feature of the project is the buy-in received from not only members of ASLA who  contributed money, but also the greenroof industry  – the majority of the products and services were donated.   Major donors include:   American Hydrotech and their Garden Roof Assembly;    Emory Knoll Farms/Green Roof Plants for vegetation; and St. Louis Metal Works for edging and drains, to name a few (see  the complete list  here).

ASLA also received a $25,000 Chesapeake Bay Small Watershed Grant from the Chesapeake Bay Program, a partnership between Virginia, Maryland, Pennsylvania, the District of Columbia, the Chesapeake Bay Commission, and the federal government.

Keith Swann, Special Assistant to the Exec. VP, American Society of Landscape Architects, shares the following info with us:

The American Society of Landscape Architects Green Roof Five Years Later

The ASLA green roof still continues to amaze all who visit it. And those visitors have come from as far as the Middle East, Far East and Australia to witness its beauty. With its wide variety of soil depths and diverse plant selection, this green roof offers many microclimates for the plants to thrive. From the terrace level with three inches of growing medium, the sedums have thrived under the innovative grating system as well as the in the other areas. This grating, aluminum, light-weight and recyclable, allowed a maximum planting area and walkable space on the roof. The bonus is the sedums bloom at your feet in addition to on the “waves” bringing a wide abundance of plants and color to eye level for everyone to enjoy.
 
In addition to the terrace level and waves, the newly added staircase, which makes this a popular public project, has 12 inches of growing medium and flourishing shrubs of fragrant sumacs, Pasture rose, and New Jersey tea. The elevator shaft has 21 inches of growing medium and houses the Flame sumac and the trumpet vine that is covering the trellis for additional shade as you enter the green roof.

By using the Hobo temperature monitoring system, the green roof has shown a maximum temperature difference of 43.5 degrees lower than from a nearby tar roof.   As the plants have matured, this temperature has risen from the initial reading of 39.5 degrees lower. The expectation is that as the plants mature even more over the years, the temperature difference between the two roofs would continue to increase.   As a demonstration project, this type is data is very useful in determining the just one more attribute of how green roofs are healthier for the environment than conventional roofs.

The roof has been monitored for stormwater runoff, water quality (to determine the concentrations of contaminants of concern leaving the greenroof), and air temperature  and is  compared with data from the conventional roof on the building next door.   See a synopsis of comprehensive water monitoring data from the first year of the ASLA Headquarters’ greenroof here  or the full briefing report (both .doc files).

The ASLA is  very committed to promoting the work of landscape architects and greenroofs, so much that they have a  section of their website  devoted to the subject – Green Roof Central, where you can learn all about greenroofs in general as well as their own.    There’s a webcam showing the HQ greenroof and a page for educators and students – the ASLA Green Roof Education Program, The Roof is Growing!   The program provides print and web-based educational materials geared to a middle-school age audience (grades 6 –  8) and their teachers.   Key goals of the program are to raise awareness of environmental issues and the role green roofs can play in reducing storm water runoff, mitigating the urban heat island effect, improving air quality, and providing important biohabitat for birds and insects.   (In 2007 I  was one of the expert reviewers of the four segments of the  “The Roof Is Growing!” web component.)

Advocacy  is a also a big item for the ASLA – they focus on  state and federal issues that impact the profession of landscape architecture.  Advocacy efforts are organized around these key issues: economic recovery, transportation, sustainable design, livable communities, water & stormwater, and historic landscapes.

 

Greenroofs.com highlighted the ASLA HQ greenroof in our 2009 Greenroofs of the World™ Calendar for the month of August with the photo  above (but we Photoshopped out the ad on the brick wall per their request), and as familiar as I am with this roof, I haven’t yet visited this lovely, warm green space created with humans and nature in mind – but I promise, I will!   See a one and a half  minute video of the ASLA Green Roof from the organization  below for a quick visual of this beautifully designed, ecologically inspired, showcase of responsible architecture:

The  American Society of Landscape Architects (ASLA) Headquarters  is located at 636 Eye Street NW, Washington D.C. 20001.   Tours of the ASLA greenroof are available for groups or individuals on Tuesdays, Wednesdays and Thursdays between 10:00 am and 2:00 pm by calling ASLA at 202.898.2444 or filling out a form.

 ~ Linda V.

GPW: Westview Condos

April 25, 2010 at 9:40 pm

Where can you find urban rooftop sophistication that meets a native Tennessee landscape on a rehabilitated condo building?   Greenroofs.com’s Greenroof Project of the Week is the Westview Condos in Nashville, Tennessee –  a wonderful example of urban renewal by incorporating  beautiful and  much needed nature on an exclusive,  10-unit residential  building  in the heart of a bustling city.   Originally a corporate office building, the renovated property was converted to high-end, mid-rise condos in 2005.

 

The first residential greenroof in Nashville,  the 8-story  structure was redeveloped to provide exclusive and luxurious loft condominiums with spectacular views of downtown.    A lobby and commercial space occupy the first floor with indoor parking on the second level, leaving six floors for residences, topped off with a lush vegetated roof used by residents as recreational space.

The eco-friendly project won the 2006 residential award for greenroof design from the  USGBC Tennessee chapter.

Developer Ron McClaron of McClaron and Associates chose to replace the  previous roof with a greenroof because he considered the Westview a prime location for launching an environmental demonstration project.   I met Ron in August, 2003 when he came to visit my first built greenroof project in downtown Atlanta, the 3TEN HauStudio.   He was starting research into the possibility of renovating  this former Southern Bell building into condos and wanted to pick my brain about costs, plants, etc.

The Nashville roof was in poor condition and as he looked at options, he desired considering greening the roof to take advantage of the environmental advantages and as a means of possibly enhancing the building’s value and marketability.   He knew that weight wasn’t a particular consideration in this application since the basic structural support was pre-stressed concrete –  the building was designed with the idea that Southern Bell might have desired to add additional floors at some point.

Yet, the process wasn’t as easy as might have been expected, given all the environmental and economic benefits of living roofs:

“…city officials had to be convinced this project’s benefits would outweigh difficult logistics associated with downtown construction and transportation of greenroof building material, and potential fire safety hazards.” ~ Southeast Watershed Forum Case Study

The Tennessee Valley Authority  (TVA) contributed funds in the form of grants in order to use this as a demonstration project of their commitment to sustainability.   You must agree that Ron’s original vision for a more sustainable redevelopment was successful – the condos range from 2,300 to 5,00 sf and all ten units were sold quickly.    In fact, many homeowners had identified the greenroof as their top reason for buying in The Westview.

The private roof top garden provides a 360 degree vista of Nashville including the State Capitol,  and homeowners entertain their guests in four separate sitting areas, including  a gazebo, while watching butterflies and listening to birds.   They even have a gas grill and wine chiller for comfortable dining al fresco, surrounded by trees, shrubs, grasses, and blooming perennials!

As you may know, Ralph Velasquez is our Sustainable Roofing Editor, but in 2005 he was the Greenroof Consultant for the Westview Condos project as president of  his previous company, Integrated Building Technologies (currently he is now Director, Sustainable Technologies  Group with Tremco Inc.).   FAMOS GmbH  greenroofing membranes and two-ply modified bitumen built up system were used, supplied  through Building Logics  (see more details in the project profile).
 

The RD Herbert Roofing Company installed the roof system and provided metal edgings and other custom metal products.   And the case study  on their website adds that “wall flashings were covered with a soy-based reflective coating for aesthetic and environmental reasons.”   Another ecological feature is the pavers, which are made of recycled tires.   Landscape architectural services were provided by Lose & Associates.
 

Landscaped with all native southeastern U.S. plants from GroWild, the  peaceful retreat  includes American Smoketree, Serviceberry, Blueberry, Prairie Dropseed, Little Bluestem and the federally endangered Tennessee Coneflower.   Owned by the husband and wife team of Mike Berkley and Terri Barnes, GroWild  is a Tennessee plant nursery specializing in native North American plants.   GroWild has over 850 species and cultivars of native perennials, wildflowers, trees, shrubs, vines, and grasses.

The growing media from Mr. Natural contains Permatill, an expanded slate,  and  other rooftop mixtures, provided by Ernie Higgins of  ItSaul Natural, with a depth that  ranges from 6″ to 30″ .     The lightweight “Roof Planting Soil” for intensive greenroofs provides the native plantings all they need for sustained health and growth.

Metro Nashville now has many greenroofs in place, with more planned or on the boards.   I haven’t been to Nashville in many years, and would love to see this gorgeous vegetated roof, along with several others here, the next time I’m in the area.   You’ll be happy to know that this roof is available for occasional viewing, by appointment only.   To schedule a tour of the  Westview Condos greenroof, please contact Mike Berkley at GroWild, Inc. at: 615.799.1910 or growildtb@aol.com.

 ~ Linda V.

GPW: Asphof Hen Unit

April 17, 2010 at 10:58 pm

Our Greenroof Project of the Week (GPW) is the rustic extensive 1,000 m ²   “Asphof Hen Unit” greenroof in the beautiful countryside of Rothenfluh, Switzerland.   A conglomeration of seven medieval villages, Rothenfluh is a picturesque municipality in the district of Sissach in the canton of Basel-Country in northern Switzerland.

Aramis and I had the pleasure of visiting the lovely area in September, 2005  where I presented my paper “An International Call for The Greenroof Projects Database” at the first  The World Green Roof Congress held at the University of Basel,  Switzerland.   The Congress was co-organized by ZHAW – Zurich University of Applied Sciences Institute of Environment and Nature Resources, Centre Urban Greening, Competence Centre Green Roofs (Hochschule Wädenswil) – and the  International Green Roof Association (IGRA),  among others,  and the tours were led by graduate students and volunteers from ZHAW/The World Green Roof Congress.

We jumped at the opportunity to join one of the local tours that encompassed “Green Roof Week” from September 12 -17.   Congress attendees had a choice of a wide-ranging excursion program ranging  from one to three-day trips, “showing examples of good practice on famous green roofs in Switzerland and the surrounding area of Basel.”    We opted for a one-day tour and wonderful host and guide was  Nathalie Baumann, MSc / Biogeograph, ZHAW Research Associate, who specializes in the ground-breeding Lapwing bird population nesting atop various brown and greenroofs in the area.

We visited six very different applications, from one of Nathalie’s research sites atop a huge pharmaceutical manufacturer to the largest solar roof installation with greenroofs in Switzerland, to a greenroofed cattle barn and this organic chicken farm with two greenroofed structures, where we enjoyed a fantastic Swiss lunch, too.

The owner, Matthias Eglin, really wanted to tread lightly upon the land in terms of blending the large chicken barn/coop into the landscape and providing  a literally cooler environment for his 2,000 organically-raised chickens.  

He turned to renown biodiversity researcher Dr. Stephan Brenneisen of Hochschule Wädenswil (also the coordinator of the  World Green Roof Congress and president  of the  Green Roof Competence Centre), who served as project consultant for the Canton Basle Rural’s Nature and Countryside Protection Commission – see the federal service project on ZHAW’s website.   Their intent was to establish  an extremely  low maintenance xeric landscape  on top of an agricultural utility building and have it eventually naturalize  to mimic the surrounding terrain.

So in 2002 they constructed the Asphof Hen Unit using inexpensive local materials – so local in fact that they harvested and shred Miscanthus sinensis (China grass/reed) from Mathias’ own property to serve as an inexpensive lower substrate and water retention layer.   They excavated  5 cm of loamy humus topsoil from their former orchard area and used it  as a free growing medium.   The annual Phacelia tanacetifolia (Lacy Phacelia), used extensively in Europe both as a cover crop and as bee forage, was included in the grass  seed to break up the soil mix and act as erosion control.   Other herbs were included in the roof as well.   Here’s the roof, below,  in 2002:

And below, three years later, in 2005:

The  natural temperature control reduces the heat by up to seven degrees in the summer (relative to outside temperatures), due to cooling effects of evaporation, resulting in more stress-free chickens!   When we were there it was fun to watch them roam freely about the property, hopping from one roof to the next.

Getting up to the roof took some care and trust that people were holding the ladder on both ends – and as usual I didn’t have the best shoes on..but it was fun!   And it was very grassy:

The second 1,200 sf greenroof is found on the Hay Shed Greenroof, constructed in 2005,  which shelters hay rolls used on the farm property.

Christine Thuring served as a Congress team member and guide on one of the other tours during the Congress.   Co-founder of Green Roof Safari (and Chlorophyllocity and, of course, one of our contributing editors), along with Jörg Breuning (of Green Roof Service, LLC)  she has lead tours here since, as well.   Green Roof Safari offers special access to the European greenroof industry with custom designed tours with multi-lingual guides specializing in highlighting current and historical trends in policy, research and design for the areas visited.

Christine shared these two photos with me and informed me that the roof continues to be monitored, especially the soil substrate and how it has developed with time – Dr. Brenneisen above with the group, and measuring the roof soil below:

Christine succinctly says of the project:

“The Asphof chicken shed demonstrates innovative, economic, simple success.” ~ Christine Thuring

So successful that they don’t even mow it – the roof meadow acts as a self-sustaining system, fully integrated into the landscape.

If you’re interested in seeing this project, you’re in luck.   Now in its sixth year Livingroofs.org Ltd will be again partnering with Hochschule Wädenswil for their famous “Swiss Green Roof Tour 2010” which  will be held on May 6-7, 2010.    You’ll not only get  Dr. Stephan Brenneisen, but also the indomitable Dusty Gedge, Director of Livingroofs.org, both of whom are internationally recognized for their work on greenroofs and biodiversity.   Much of the focus of the tour is how research in Switzerland has developed an approach to green roofing that has biodiversity at the heart of their design.

From roofs designed for lizards, to those that have been designed for rare bees, beetles and spiders, this year the tour includes visits to roofs where Swiss researchers are studying ground nesting birds – and to where chickens are happy, too, on the ground and on the roofs.

~ Linda V.

GPW: Private Seattle Green Roof Garage

April 11, 2010 at 11:57 pm

The Pacific Northwest in general is known for eco-friendly, sustainable building policies, high-performance green architecture, and local innovative building designs.   In fact, Seattle holds the distinct position of being the first U.S. city government committed to Silver LEED™ facilities, adopting its Sustainable Building Policy requiring new city buildings over 5,000 sf to  obtain the U.S. Green Building Council’s certification rating in 2000.   But the Seattle area also distinguishes itself in that it has an unusually high number of residential greenroof applications.

Our GPW through today is the lovely 280 sf “Private Seattle Green Roof Garage,” built in 2003 by architect Rob Harrison and his wife, Frith Barbat.   Located in a geographically diverse southeast Seattle neighborhood,  the area is filled with parklands, lakefront, wooded hills, and quiet residential streets and boulevards.   Aside from the living roof, construction methods were eco-conscious from the beginning as the homowners  capitalized on the property’s existing carport  foundation and built  the garage mostly with materials salvaged from the previous deck.   It’s really not surprising, since Rob Harrison, AIA, is a Certified Passive House™ Consultant and principal of HARRISON architects.  

The  Seattle, Washington firm  has been in business since 1984, with the last 18 years devoted to sustainable design.   HARRISON architects’ work is based in “lyrical sustainable design”: conserving energy and resources, using healthier materials and finishes, reducing long-term costs, and making poetic places.   By working with consultants, contractors and suppliers who share their values, the  experience  results in a convivial, collaborative design and construction process.    And when you’re the client/architect, and it’s easy to be creative in this environment.

“Since it was our own house (rather than a client’s!), we thought it would be a great opportunity to experiment with a less expensive residential alternative to $15/sf proprietary (and warrantied) green roof systems used on commercial projects, and so promote the use of green roofs in residential applications.” ~ Rob Harrison

And since Rob was a  member of the local chapter of the Northwest EcoBuilding Guild, he had plenty of local expertise and volunteers for help.   The Northwest EcoBuilding Guild is an alliance of builders, designers, suppliers, homeowners, and partners concerned with ecological building in the Pacific Northwest.   Their mission is to provide leadership in education to transform the built environment and build a sustainable society.   In those years, hadj design  directed the greenroofing efforts for the Guild,  and the firm’s principal, Patrick Carey  (also our Architecture Editor), was one of the consultants and volunteers on this project, as seen below in the bucket brigade system used to haul the growing media up to the roof.

Originally, Rob designed the space to call his own for a “manly” workshop (the garage is featured on the cover of the book ManSpace: A Primal Guide to Marking Your Territory by Sam Martin, about “dens, caves, lairs, hangouts, hideaways, workshops, studios, drinking sheds and man houses”).    The one-car garage  housed space for tools, one bicycle, two vintage motorcycles and  their  Mini Cooper.

But things have changed – at present, the garage now holds just one motorcycle (a new gas-efficient model with a catalytic converter) and the family’s six bicycles.    They sold  the car seven months ago, and have  been giving the car-free life a try – so far, so good!

Originally planted with Eco-Turf (a mixture of baby blue eyes, red clover, yarrow, and fescues) and a variety of drought tolerant sedums, they’ve also added strawberries, nasturtiums and poppies to the greenroof.

Venturing onto YouTube this past February, Rob came across the above advertisement for Pepsi’s new humanitarian/environmental effort, the Pepsi Refresh Project, and was surprised to see his own green-roofed garage!  He explains that a couple years ago fashion/rock star photographer Karen Moskovitz came over with a young model family to shoot some stock “lifestyle” photos and video using his garage as the backdrop.  He’s quick to point out that it’s not him watering the roof!

“We might do that if we’ve planted new plants up there and need to get them started, but otherwise, not,”  Rob says.   Actually, maintenance has been  really minimal – they only watered the first year during establishment and have only spent about one  hour’s worth total weeding and the occasional introduction of new plants during the first three years.   He adds, “It’s a bit odd to be shilling Pepsi, even if very indirectly, but I do like the idea that we are clearly living in some one’s idea of a better future!”

By the way, the Pepsi Refresh Project  is looking for people, businesses, and non-profits with ideas that will have a positive impact in their communities, and is giving millions of dollars in grants in the categories of Health, Arts & Culture, Food & Shelter, The Planet, Neighborhoods, and Education.

Any lessons learned with a greenroof so close to home that you can see daily?   In the more recent photos that Rob sent me, see above and below,  it’s obvious the roof has seceded to mostly grasses, so I asked him if is it still that way – Yes.

Rob says now that the roof is seven years old, in retrospect he would not have introduced any grasses on the roof at all, as the area planted in Eco-Turf has spread over the entire roof and overtaken the sedums, which  are still there, but are hard to see.   But he muses,  “The wavy grass does have its own attractions, especially in the dry summer here, where it reminds me of the Palouse in eastern Washington.”

Does he plan to keep it as it has naturalized or does he have other designs?   Rob’s response:  

“I’m of two minds on the secession of the roof to mostly grasses.  On the one hand I like the look of the grass, and the way the motion of the grass in the wind animates the building, and it’s tempting to let the roof do its own thing and see what develops naturally.   On the other hand, grass forms a dense mat of roots that is surprisingly impermeable.   We haven’t made a big decision to replant the whole roof yet, but we’ve been pulling out clumps of grass here and there, and planting more sedums as we acquire them from friends and neighbors.”

This beautiful private  Seattle vegetated roof  is one example of sustainability on a smaller scale in a city full of greening efforts.   It has been featured in many  publications  and tours, both public and private. The photo above  resulted from an AIA Seattle seminar on greenroofs held at  the architect’s  home in 2006, in conjunction with folks from Bohlin Cywinski Jackson.

Visible from the alleyway behind it and, more importantly, from the home’s  kitchen window, the Harrison/Barbat family agrees their Seattle garage greenroof is a pleasure to behold every day – in all seasons and all forms.

~ Linda V.

(Note:   See Patrick Carey’s  article about the Northwest EcoBuilding Guild  from June, 2003 here, and my August, 2004 Sky Gardens ~ Travels in Landscape Architecture column about Seattle’s early sustainability leaders and efforts here.)