New Case Studies on Sustainable Landscape Design

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Sherbourne Commons / ASLA 2013 General Design Honor Award. Sherbourne Common / Phillips Farevaag Smallenberg

A newly expanded and now mobile-friendly version of ASLA’s Designing Our Future: Sustainable Landscapes online exhibition highlights real-world examples of sustainable landscape design and its positive effects on the environment and quality of life. These spaces use natural systems to provide ecosystem services, transform untapped assets into vital community spaces, and create new economic opportunities — they ultimately provide significant environmental, social, and economic value.

Ten new case studies that range from a coastal ecological restoration project to a volunteer-run urban farm illustrate just what sustainable landscapes are and how they provide important benefits on a variety of scales. In the process, the case studies, written in clear, understandable language, also introduce users to what exactly landscape architects do.

The new case studies were carefully selected to show a diversity of landscape types and scales and reflect geographical diversity. There are now a total of 40 case studies.

New case studies include:

Burbank Water & Power Eco-campus, Burbank, California, a sustainable landscape for employees and visitors in the midst of a working power plant.

Drs. Julian and Raye Richardson Apartments, San Francisco, California, a safe and welcoming apartment complex, with beautiful design elements, for the chronically homeless.

Lafayette Greens, Detroit, Michigan, a volunteer-run urban farm in downtown Detroit where 800 pounds of fresh fruit and vegetables are grown every year.

Living Breakwaters, New York, New York, an innovative coastal ecological restoration project that won $60 million in the Rebuild by Design competition sponsored by the U.S. Department of Housing and Urban Development (HUD).

Pete V. Domenici U.S. Courthouse Sustainable Landscape Renovation, Albuquerque, New Mexico, an underused plaza that has become a model of sustainable landscape design in the desert.

Quarry Garden, Shanghai, China, a derelict, polluted quarry that was transformed into a garden visited by more than 3 million people in its first year.

Sherbourne Common, Toronto, Cananda, a multi-functional park and wastewater treatment plant that includes an underground Ultraviolet (UV) water purification system.

The Steel Yard, Providence, Rhode Island, an abandoned steel manufacturing facility that has become a beloved community arts space.

Sunnylands Center and Gardens, Rancho Mirage, California, an extension to the Annenberg Estate that captures every drop of stormwater, with some collected in underground cisterns for later use.

Woodland Discovery Playground, Memphis, Tennessee, an immersion in nature play for children that features surfaces made of recycled athletic shoes.

The Web site also 30 other case studies; 10 animations created by Daniel Tal, ASLA, using Google Sketchup; and companion sustainability education resources that enable users to explore sustainable design concepts in greater depth.

Designing Our Future: Sustainable Landscapes was originally made possible with a grant from the National Endowment for the Arts (NEA).

The Humble Public Bench Becomes Comfortable, Inclusive, and Healthy

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The Plaza bench / Stoss Landscape Urbanism

“People now want to be comfortable when they sit on a bench,” said Erik Prince, ASLA, Stoss Landscape Urbanism, in a session on urban furniture at the 2013 ASLA Annual Meeting in Boston. “It’s no longer about making benches uncomfortable for vagrants and the homeless.” In a tour of the humble public bench’s past — and its potential future — Prince, along with Jane Hutton, assistant professor of landscape architecture, Harvard University, and architect Robyne Kassen, Urban Movement Design, explained how a shift in public furniture design may reflect broader societal changes and could be leading us towards healthier, more inclusive public spaces.

Prince said some contemporary benches, like the one Stoss just hand-designed and fabricated for The Plaza at Harvard University, provide a “new organization of social space” (see image above). These “more ergonomic” benches allow for “multiple functions, like stretching, playing, and lounging.” These new functions are only made possible through a revolution in design practices, like 3D modeling and fabrication. Some of these new benches are designed to be inherently flexible, with “changeable forms” that can create a “new sense of community.”

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The Plaza bench / Stoss Landscape Urbanism

The History of Public Furniture

Hutton said the many types of benches throughout history have offered unique ways of sitting and interacting with the surrounding environment. “Different materials and inclines generate different social realities.” Benches can either be “solitary or social, exclusive or inclusive.” While they are often “invisible in the landscape,” public benches are actually central to our appreciation of landscapes, as they “organize the scope and our scoping strategy.”

In the 14th century, Tuscan civic benches were built into plazas, enabling small public spaces to form for “theatrical or tribunal purposes.” These benches helped “convey the sense of civic action and stimulated popular use.” They were about half a meter wide, so you couldn’t sleep on them.

In the 18th and 19th centuries, communities started creating the “rustic twig bench,” which reflected a “transcendental, natural philosophy.” As an example, “crude” benches in Central Park, NYC, worked with a “pastoral ideology.”

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Park Bench by William Merritt Chase / Wikipaintings

In the 19th and 20th centuries, garden chairs started to be mass produced. Carved wood chairs, which were never comfortable, were now made out of iron, with “intricate plant and animal motifs.” Hutton said these were “very uncomfortable,” largely because they were meant to be “show seats when not occupied.”

In the 1860s, the first comfortable, mass-produced, iron garden chair was created, along with a low-cost folding chair, which was iconic in the military arena and also featured prominently among colonizers in Africa and Asia. These light-weight garden or foldable chairs were soon available for rent in public parks. In the gardens of Versailles, there was a garden chair with a fold-able back.

The Central Park settee, one of the first designed, stationary public benches, was made with a mix of iron handles with wood slats. “It was just under relaxing,” Hutton added. From then, there was a proliferation of “benches in street furniture.” None were particularly comfortable because then the thought was “you should hold your own posture, not rely on the chair.”

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Central Park settee / Central Park Conservancy,

In the 20th century, there were experiments about the human figure and ideal reclining positions. Furniture studios examined “free-form ergonomics,” exploring how a mix of “rigid and contoured” cement and fiberglass could be created to create an ideal form. This era led to some of the “iconic chaise lounges” that populated Garrett Eckbo’s “modern landscapes for living.” Marcel Breuer created his famous lounge recliner. Later, Panton explored the use of plastics. “These were for play and pleasure.”

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Panton Chair / Wikipedia, Holger.Ellgaard, CC BY-SA 3.0

For a period of time, public benches were purposefully made uncomfortable in order to deter unwanted elements. “They were defensive or deterrent furnishings.” But today, Hutton said, the shift is towards more comfortable and relaxing public furniture, which even enable “splaying in public,” a posture once only allowed in the “medical or residential spheres.” There’s now a potential for “new positions in public spaces.”

Ergonomic Positions Made Possible by New Technology

With 3D modeling and fabrication, new possibilities like Stoss’ benches for Harvard are now possible. The bench, Prince said, has “numerable, inter-changeable seating positions,” which were mapped out using the software program Rhino, with a Grasshopper add-on. “We use parametric modeling tools.”

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The Plaza bench / Stoss Landscape Urbanism

There are 17 benches, made up of 7 types, each with similar ergonomically-sound geometries. Some have high backs, some have low. Some are upright, while others are low-to-the ground. Prince said Stoss “applied rules to the types.”

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The Plaza bench / Stoss Landscape Urbanism

Each bench type was created as a 1-to-1 prototype to “incredible precision” using advanced fabrication technologies. Getting all the joints to meet properly required an incredible attention to detail.

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The Plaza bench / Stoss Landscape Urbanism

The wood used was found in one of Harvard’s depots. Leftover from a new Renzo Piano-designed building, the “temple-grade cedar wood” was Alaskan first-growth forest wood. While he said they would never usually use wood like this, it was local sourcing of reusable materials in this instance.

The Bench That Boosts Your Health

Robyne Kassen, an architect and yoga instructor, said a bench or chair changes your body as you sit in it. She said we are “constantly becoming our bodies,” so a chair or bench has significant impact.

Sitting at a computer all day long — and not getting up to move around — is the health equivalent to smoking a pack of cigarettes a day. Spending all that time in one position is particularly dangerous, given we are “always training our bodies and they are becoming. We are the filters through which we experience the world.”

Our nervous system — a key part of how our bodies experience the world — is also taxed all day long. Blinking, loud signage affects our nervous systems. Too much stress from the built environment can damage our sympathetic systems’ flight or fight response. Our para-sympathetic system, which enables relax and release, can then get out of balance, causing illnesses.

To maintain health and well-being, “we must nourish our para-sympathetic system,” which she said involves sitting at your “zero point” for a period of time during the day.

To enable the public to reach their zero point more often, Kassen and her team created Unire/Unite, an installation in a plaza near the new MAXXI Museum in Rome. The plaza’s benches are made of wood frames covered in “concrete canvas,” a special material that has concrete on the inside and canvas on the outside. The material was invented to help with water conveyance in infrastructure projects.

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Unire/Unite / © Cecilia Fiorenza via Urban Daily

The installation features an “infinity system,” which enables visitors to take on a variety of body positions and do yoga-inspired exercises meant to “activate, strengthen, cleanse, and balance the mind and body.” Here’s Kassen’s zero point:

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Unire/Unite / © Cecilia Fiorenza via Urban Daily

The plaza was purposefully designed to be accessible to everyone, with pathways of recycled rubber and low access points that enable even visitors in a wheelchair to transfer to the edge of the benches. “This landscape, play, park, space enables 66 different positions,” said Kassen.

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Unire/Unite / © Cecilia Fiorenza via Urban Daily

In contrast with the 14th-century Tuscan plaza-bench or the purposefully-uncomfortable iron garden chair, these zero-point-inducing benches clearly reflect today’s obsessions with comfort, technology, health and well-being.

Landscape Architects and Their Clients Tackle SITES

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We often hear from landscape architects about the cutting-edge sustainable design practices they are bringing to their latest Sustainable Sites Initiative™ (SITES®)-certified works, but we rarely hear from their clients. In a session at the ASLA 2013 Annual Meeting in Boston organized by Liz Guthrie, ASLA, professional practice manager at ASLA, landscape architects and their clients together discussed their motivation to become certified Sustainable Sites Initiative (SITES) projects, the challenges involved in working with this new 200-point rating system, and the lessons learned.

Why a Sustainable Landscape?

For Richard Piacentini, Phipps Conservatory and Botanical Gardens, the goal was to apply “systems-thinking” to their new Center for Sustainable Landscapes, which received the first four-star rating from SITES (see image above). “We wanted to know how we could truly integrate the building and landscape.”

He said too many buildings are “completely isolated nature.” This is a real problem because humans now spend about 80 percent of their lives in buildings of some kind. With the new center designed by landscape architecture firm Andropogon Associates, “nature is now not that far away.”

In the Bronx, Hunts Point Landing, a two-star SITES-certified landscape developed by the New York City Economic Development Corporation (NYCEDC) and designed by Mathews Nielsen Landscape Architects, shows how a “dead-end” in an isolated and unhealthy neighborhood can be turned into a park, said Kate Van Tassel, NYCEDC. The park is meant to ameliorate some of the health problems in the community, which has some of the highest rates of asthma and obesity in New York City.

The new Hunts Point Landing took shape on the site of an old coal gasification plant. Van Tassel said this little bit of “green space amid industry is very important.” To boost neighborhood health, NYDEC wanted a sustainable park. Old local materials were re-used within the park. Stones from a nearby bridge taken down were turned into blocks to sit on. The waterfront park helped “transform the shoreline into a recreation area.”

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In the case of Taylor Residence in Chester, Pennsylvania, Margot Taylor, ASLA, is both the client and landscape architect. Taylor wanted to create a public demonstration project for sustainable landscape best practices on her own property. Her property includes wood systems and meadows. Ecological systems were re-established, with a focus made on soil and plant health. The landscape, which used to be a farm, now “directs, holds, absorbs, and cleans water.” She now has hundreds of people, including lots of school groups, touring the landscape each year.

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One of Taylor’s goals in the move to a sustainable residential landscape was to reduce annual maintenance. She wants to get maintenance down to 55 hours a year. She has also “completely gotten mowing out of the system.”

Representing both himself and his client, Hunter Beckham, ASLA, SWT Design, described the design of the Novus International campus in St. Charles, Missouri. He said a “huge number of stakeholders” were involved in creating a sustainable campus, which was designed to yield many benefits for both employees and the environment. There’s a productive, edible landscape: a vegetable garden with bee-friendly plants. There are two bee blocks that provide home to seven different local species. In the first year, the landscape yielded 65 pounds of honey.

This vegetated garden terrace is accessible via a walking loop that circles the entire campus. The loop enables both employees and visitors to take a break from the office and get out in nature. Within the landscape, an old concrete-lined water detention pit was turned into a natural water habitat that manages stormwater and attracts a wide range of wildlife, including snakes.

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What Were the Challenges?

For Jose Alminana, FASLA, a principal at Andropogon and one of the guiding forces behind SITES, the benefits far outweighed the challenges. He said achieving 4-stars for the Phipps’ Center for Sustainable Landscapes was no small feat, but perhaps made possible by the fact that “we started with no site.” The design team then had “complete control over the materials used,” which helped them improve site performance and earn points under SITES.

Still, “procuring the sand-based soils was a challenge, given the firms involved in fracking are very interested in applying the same soils to sites where they are extracting gas.” Separately, he added that it was “hard to change the plant palette to accommodate the new soil pH.”

For Signe Nielsen, FASLA, SITES seemed to be an exercise in frustration. She said there were three categories of SITES credits that deeply-urban brownfield sites like Hunts Point Landing “couldn’t take advantage of,” so the project could only get two stars.

She said she couldn’t preserve existing soils and vegetation because “they were highly contaminated.” There was “no structure to adaptively reuse,” so points couldn’t be gotten there either. Lastly, there were no “cultural resources to reuse or enhance.”

She added that working with public authorities, in effect, means “limited opportunities for integrated site design teams,” as many local governments don’t incentivize such groups.

More broadly, she thought that achieving many of the credits related to “recycled content materials will be challenging given the landscape industry has very few competitive vendors in this field.”

Urban public projects may have a challenge earning maintenance points as well, as the landscape architecture firms creating these projects often have “no control over future maintenance.” A firm could create a detail maintenance manual for a park, but then that’s it.

Taylor said working with a historic farm was a challenge in itself. The native vegetation had been stripped and topsoil eroded or compacted. The solution was to “rebuild healthy soil and native plant communities appropriate for different micro-climates.” SITES, she said, “didn’t want to give credits for the landscape’s past use as pastureland.”

She certainly ended up getting credits, though, for the 27 tons of barn stone she cut up and re-purposed on site by hand. “I lost about 15 pounds shifting all that stone out of the dirt.” Still, she thinks she needs to find a “smarter way to manage materials that were unearthed.”

What Lessons Were Learned?

Alminana believes that “integrated design is really the key” to achieving a return on investment for your clients and site performance. “SITES really puts an emphasis on this.” He said, unfortunately, this approach is still not “happening among a majority of the profession or in the public sector.”

Directing himself to those who complain they haven’t earned enough points for their projects using SITES, he said “if you are only focused on points, you are missing the point.”

Nielsen believes SITES can have a potent impact, given “metrics are crucial” and SITES really forces landscape architects to collect data and measure themselves against benchmarks. She said putting all that time into collecting metrics was worth the effort because it helps “clients understand the value of our work.” Landscape architects can measure how well they’ve “reduced noise, saved water, and reused materials.” Beckham reiterated how valuable SITES is as a “framework for accountability.”

Taylor learned that it’s important to “integrate a long-term land management perspective from the beginning,” something that SITES promotes.

The landscape architects all hoped that governments — both local and national — will get moving on incorporating SITES guidelines into their request for proposals (RFPs), which can also help push the landscape materials industry to provide more sustainable options. It will be a back-and-forth process to make SITES more mainstream: landscape architects, and their clients, must push for change among providers of landscape materials, but the market must also provide opportunities to enable that change.

Image credits: (1) Phipps’ Center for Sustainable Landscapes / Denmarsh Photography, (2) Hunts Point Landing / Mathews Nielsen Landscape Architecture, (3) Taylor Residence / Mark Gormel, (4) Novus International / SWT Design

More Paver Power

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Landscape architects in Europe are doing really innovative things with pavers, perhaps more so than in the United States. Some recent contemporary urban plaza projects from Amsterdam, Copenhagen, and Barcelona show the amazing visual effects that can be achieved with bold paving patterns.

In a barren lot where there used to be a railway station, just west of Amsterdam’s city center, LANDLAB created Funenpark, a new courtyard for a residential complex. The standard Dutch courtyard, which usually has separate streets, pavement, parking and front and back-gardens, instead gets a contemporary take, created as one “continuous, luxurious” place. This Dutch landscape architecture firm purposefully kept things simple in order to create a distinct space residents and passers-by can easily wander through.

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To achieve this, the firm writes in Landezine, “we designed an intensive network of paths made of two specially designed pentagonal concrete paving stones in three shades of grey. These were laid down in a random fashion which resulted in a directionless, rugged pattern that looks like an unidirectional stretched fishnet from above.” The green parts of their landscape also really make the pavers pop. Among the grass are scattered groups of Robinia pseudoacacia and odd daffodils.

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In Copenhagen, a busy downtown shopping street gets a contemporary update. A long, curved street set in the “labyrinthine medievel city center,” Købmagergade shopping street uses “strong materials such as natural stone” in a few different colors to create a “harmonious appearance,” writes Karres en Brands and Polyform in Landezine.

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There are reasons behind the use of different colors: “The layout of the three squares is varied, just as their historical situation and their location in the city are varied. On the Kultorvet the dark – almost black – paving pattern of the stone is inspired by the 18th century coal trade. On the rather more peaceful Hauser Plads square, the exciting grass play mounds form a green oasis in the urban fabric. At night, the Trinitatis Church square with its famous observatory Rundetårn is transformed by artificial lighting into an enormous starry sky. The three squares are diverse in colour, from dark coal to bright stars: ‘From Kultorvet to the Milky Way’.”

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Finally, Passeig de St. Joan boulevard, a project in Barcelona, makes wonderful use of grass and pavers together to create a stunning visual effect. The boulevard was first laid in 1859. Over the years, it began to fall apart, creating accessibility problems. In remodeling the street, the Barcelona city government also wanted to revitalize Ciutadella Park, a set of small urban parks alongside it.

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In Landezine, landscape architects with Spanish firm Lola Domènech write that they first re-organized the pedestrian routes. “Some 17m of pavement have been organized so that 6m are allocated to a pedestrian pavement, while the remaining 11m under the rows of trees are for recreational uses (benches, children’s play areas and bar terraces). As part of the new layout, the two-way 4m bicycle lane is physically segregated, protected and signposted, located in the middle of the road.”

Together with the new street, the park was revamped to be more sustainable. The use of pavers and vegetation works together in the park to aid in stormwater management. “In order to guarantee the sustainability of this new layout, we needed to ensure proper drainage of the subsoil and take on the challenge of incorporating a mixed pavement system in the tree-lined zone. The treatment of the soil with mixed pavements and the automatic watering system that uses phreatic water are key to ensuring substrata drainage that will guarantee the survival of the vegetation. The incorporation of local shrubs to this tree lined zone will contribute to enriching subsoil biodiversity.”

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Different pavers are also associated with different human uses: “The pedestrian section the pavement is made of ‘Panot’ paving slabs (typical ensanche paving), while, in the recreational zones, a new prefabricated pavement with draining joints was laid down.”

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See more interesting uses of pavers in Europe.

Image credits: (1) Funenpark / Anne ten Ham, (2) Funenpark / Jeroen Musch, (3)  Funenpark / Anne ten Ham, (4) Købmagergade shopping street / copyright Ty Stange, (5-6) Købmagergade shopping street / KBP, (7-10) Passeig de St. Joan, Barcelona / Lola Domènech

Paver Power


A number of bold new works of contemporary landscape architecture in Europe show the power of pavers, those small, sometimes interlocking sets of paving materials. Creating a sense of depth and quality with simple geometric forms, these projects are subtly elegant. Here are a few offering unique textures that may draw you in:

In the new city center of Nieuwegein, Netherlands (see image above and below), Dutch firm, B+B Urbanism and Landscape Architecture, turned an outmoded shopping mall into a new “vibrant heart” for this relatively new city. The theme, a “blooming city”, is represented in the bold paver patterns, says the firm in Landezine. Natural stones are used in a mixture. “The pattern breaks free of both plan and architecture by means of an abstract representation of such natural elements as branches and flowers.”



Another form of city center, a new town hall square in Solingen, Germany, by German firm scape Landschaftsarchitekten, is an “urban living room” for the municipal workers in the surrounding building. Again, a bold geometric pattern is used to create a striking landscape. The design team writes in Landezine: “To build a coherent area, a pattern of black and white lines traces the whole public open space. Like a marquetry, a connecting concrete carpet integrates various functional elements and provides zones with different characters and uses.” The central square is defined by the pattern, as are the sides of the green spaces, which allow for movement. 



Four courtyards then serve as a “counterpart to this open, lively square.” The courtyards are arranged as “abstract gardens.” Notice how the black and white pavers transform into less hard-edged strips of gravel, with plants coming into the mix. In fact, wherever nature appears, the black and white pavers seem to disintegrate.

 

In Pas-De-Calais, France, the old textile mills along the banks of the Haute Deûle canal are being transformed into a new park. Designed by Atelier des paysages Bruel-Delmar, the project pays honor to the canals and irrigation ditches, but creates something new as well. Working class factories and dorms are now office buildings for high-tech workers. Public spaces and a new water garden filled with phytoremediating plants draw in residents from the community and techies taking a break. 



The design team wanted to create new public spaces without “depriving this quarter of the charm that resides in the proportions of the streets bordered with worker houses.” A new courtyard creates the sense of a hard linear park that respects the working class vibe, while pavers made out of concrete and industrial basalt create texture along paths. 



Image credits: (1-3) Blooming City Center / Renee Klein, Frederica Rijkenberg, (4-7) Town Square, Solingen, Germany / atelier 2, Gereon Hofschneider scape Landschaftsarchitekten, Rainer Sachse, (8-12) Haute Deule / Atelier de paysages Bruel-Delmar

Why Use Ipe When You Can Have Black Locust?

Black Locust planks. ASLA 2006 Professional General Design Honor Award. Small is Beautiful. Michael Van Valkenburgh Associates / Elizabeth Felicella

Michael Van Valkenburgh, FASLA, and his fellow speakers got multiple rounds of spontaneous applause at the 2011 ASLA annual meeting for hosting a session on a topic near and dear to many design professionals and wood experts: how to end the unsustainable harvesting of ipe wood and scale up the use of sustainable alternatives. The real alternative may be black locust (Robinia pseudoacacia), which Van Valkenburgh and other progressive landscape architects, architects, engineers, and wood manufacturers have already been using for some time.

In addition, domestically-grown black locust may offer new opportunities for local sustainable forestry businesses. The trees grow fast and are hardy (in fact, in many areas, they are treated as invasives) and can even take root in urban areas. So they could provide a new source of employment in cities like Cleveland and Detroit, where populations are collapsing and landscapes aren’t as productive as they could be.

Ipe is a tropical hardwood often used in outdoor decks and furniture because it’s so resilient to rain, insects, and weather changes. Its special properties also mean that it lasts a long time. However, there is a dark side to this wood, which is all too often still used in park and residential projects. Just a few ipe trees are found per acre in dense, lush tropical forests, which means foresters must wreck havoc on the forest to extract and process those single old trees. Van Valkenburgh and others argue there must be better alternatives.

Why Black Locust?

Stephen Noone, ASLA, senior associate, Michael Van Valkenburgh Associates, said black locust lasts just as long as ipe. He said it’s a “pioneering, not invasive” plant that “takes root on sites that other plants don’t like.” Unlike ipe, the tree grows together in densely planted areas. In Europe and Asia, it’s already treated as an acceptable crop. In fact, a number of countries are moving forward with planting large groves for wood production, a business that, oddly, has failed to take root in the U.S.

A research project by Michael Van Valkenburgh Associates’ interns found a plantation in Hungary producing a range of different quality black locust woods, including top quality woods. They found that black locust can “only be planted in marginal areas where oak can’t be established.” In a smart move, a local forestry research organization and local wood producers afforested a massive area. Now, 8,500 hectares of dense black locust forests are being harvested in one area there.

Black locust has “high natural durability, is heavy and hard, but has a tricky kiln drying process,” said Noone. It’s “not going to rot and is insect resistant.” Noone delved into the details of moisture content, and the process needed to achieve the desired content levels. There is a complex multi-step process that involves letting the freshly cut wood air-dry to reduce moisture and then using a “dehumidifier kiln.” Noone said “the process is very strict,” and “diligence is required on the part of the drier.” There’s also a long lead time for landscape architects: 40-50 days until the wood can be used. But it’s worth it: Beyond the sustainability benefits, black locust is also cost-effective. In bulk, it’s $5.44 per square foot, while ipe is more than $7 per square foot.

Black Locust planks. ASLA 2006 Professional General Design Honor Award. Small is Beautiful. Michael Van Valkenburgh Associates / Elizabeth Felicella

Building a Bridge in Brooklyn

A new pedestrian bridge made entirely of black locust and designed to move people from neighborhoods in Brooklyn into Van Valkenburgh’s Brooklyn Bridge Park is now taking shape. Ted Zolli, HNTB, said in this case, “black locust is better than concrete in terms of its compression, strength, and flexibility” and an “incredibly viable structural material.”

Walkway into Brooklyn Bridge Park, HNTB / Curbed NY

Zolli showed how timber bridges aren’t a new thing. Some 20 percent of current bridges are made up of wood and some are more than 100 years old. This 400-foot long bridge is comprised of pre-fabricated pieces created off-site and the delivered and installed in BK. Some parts of the bridge span 120 feet. All together, there’s about 30 tons of wood. He said for this gangway, black locust was the right way to go.

HNTB purposefully tested how vulnerable the wood is to fire and found that it doesn’t lose its strength as it burns. “It’s better than steel and will do better in a fire than the cable wires we are using.” For him and his firm, the real challenge was getting a hold of longer planks and finding the right connector systems for the bridge components.

The Properties of Black Locust

Don Lavender, Landscape Forms, a man Van Valkenburgh called a “national treasure,” discussed the opportunities and challenges in scaling up a domestic black locust industry. He said there is great potential for the tree in the U.S. but it’s about “obtaining prime examples and taking selections.” Lavender said the best trees are found in the Appalachian region.

Black locust was originally given to settlers by the government during the early expansion of the U.S. because it’s very fast growing. Within 15-20 years, the material can be cut down and burned. At 30 years old, it can be used for materials in homes. Lavender said the best of these trees “competed for sunlight with other trees.”

The tree can be used for many products, and even lesser-grade woods aren’t wasted. “100 percent of the tree can be purposefully used.” Lavender said lower grades can be used for mulch, biomass fuel, parquet, and greenhouse poles. The higher grades, #1 grade, premium and premium plus (the top 5 percent), are the result of a more challenging “kiln drying process” that requires “patience.” The wood is tough and resistant to drying for the “same reason it’s so resistant to decay.”

Once dried properly, it can easily be “cut, sawed, drilled, sanded, and shaped.” No outdoor finishes are needed and its screw retention is good. Its Janka hardness also compares favorably with other woods. At 1700, it’s better than red oak (1290), but a bit less than tropical hardwoods like jarrah (1910) and ipe (3684).  It’s also difficult to glue. But biologically, black locust is “remarkably decay resistant.”

Scaling up Cultivation and Production in the U.S.

Van Valkenburgh said the U.S. is falling further and further behind globally. “The country is losing its edge.” Currently, there are 5 million acres of black locust under cultivation worldwide, but “virtually zero in the U.S.” Korea has 1.2 million acres, China has another 1 million, while Hungary has 270,000 acres. “This is something that has the potential to be an economic engine in many parts of this country.”

Instead of being viewed as an invasive, as it is in many parts of the U.S., Van Valkenburgh said it should be grown in set-aside areas. Lavender added that the Amish, who “don’t waste anything,” has been using black locust for ages. The Amish, who have perfected techniques over generations, are in fact a perfect model for black locust production: “proper kiln drying is not something you just get into one day. It takes generations to learn this.” He added that a number of firms have “blundered into kiln drying” and ended up with kindling. “It needs to be done methodically” if an industry is going to bloom here.

Van Valkenburgh is currently using black locust imported from Hungary. A firm in Massachusetts is importing containers from Hungary and “taking it upon themselves” to expand the domestic market. While using this wood puts him out of the 500 mile range the Sustainable Sites Initiative (SITES) calls for in sourcing sustainable materials, he said “we have to think bigger about sustainability. The lifespan of these woods is several multiples higher than others.” Still, he wants to see the woods grown domestically.

The black locust market in the U.S. is “still in its infancy” despite the advocacy efforts of Van Valkenburgh and others. Hopefully, some smart city officials will see an opportunity. As one audience member said, Detroit and other cities could not only turn their abandoned lots into forests, but black locust forests. Van Valkenburgh went even further: “Planting on reclaimed sites is a great idea.”

Van Valkenburgh, Noone, Zolli, and Lavender kindly shared their 84-page presentation (8MB) full of rich content, photos, and data. Download and help spread the word.

Solar Decathlon 2011 Innovations: Constructed Wetlands, Edible Landscapes, Rain Gardens, and More


The Solar Decathlon, a design competition and public education program run by the U.S. Department of Energy, returns to the National Mall this year, where it will be open September 23 – October 2. Like the competition two years ago (see earlier post), teams of architecture and landscape architecture students from universities around the world compete to design, build, and then operate the most “cost-efficient, energy-efficient, and attractive” solar-powered home. The team that reaches optimal energy production, maximizes all efficiencies, and combines design excellence with affordability, takes home the top prize. 

In 2009, Team Germany beat out all the top talent from the U.S. and Asia with their innovative cube home entirely covered in solar panels. Given all the fundraising needed to create these projects (some of these model homes cost hundreds of thousands to create), not many of the schools from 2009 appear again this year. A whole new set of competitors are in play.

All projects have the requisite solar photovoltaic or solar thermal systems installed in various places on or around the home, but in terms of integrated site design, the University of Maryland’s WaterShed was the most innovative project this year. An attempt to create a “micro-scale ecosystem,” the project truly integrates building and landscape and uses “living systems,” or constructed wetlands to recycle and reuse greywater from sinks and showers. In combination with the wetland, exterior native plantings, edible gardens and walls, and a green roof mean the site will not only be highly energy efficient but will also be extremely water efficient and have zero stormwater run-off. 

Using plants native to this region, which creates habitat for local birds and insects, architecture and landscape architecture students at UMD constructed the wetland right outside the home’s floor-to-ceiling bathroom window so it’s clear that water from the sinks and shower flow outside to the wetlands, where the water is then cleaned and reused to irrigate the landscape.

However, their landscape also does more than clean and recycle wastewater, it also produces food. Veronika Zhiteneva, a student with the UMD team, explained that a garden plot with vegetables can help a family in their model home “live more sustainably and with greater self-reliance.” Near the garden plot, there’s also an edible wall made of twisting grape vines. 


The building’s green roof, which was grown by LiveRoof, is comprised of 150 2.5-inch deep trays, which feature six different types of sedum. Placed on the north side, the green roof not only reduces energy use by 25 percent, but also slows down and absorbs any stormwater. Any excess rainwater not captured by the roof is then soaked up by the surrounding native plants. 


In fact, the entire project, from the wetlands and native plantings to the garden and edible wall to the green roof, are designed to ensure the home only offers positive impacts on the surrounding environment. Scott Tjaden, another team member, said “our inspiration is the Chesapeake Bay,” which has suffered major impacts from agriculture and stormwater run-off. Indeed, of all the projects in this year’s Decathlon, WaterShed seemed to offer the more thoughtful approach — it places high value not only on energy efficiency, but stormwater management, water efficiency, and biodiversity too.  

Among the other 19 model homes on the Mall, a theme this year was edible landscapes. A student from the Middlebury College team (see below) said these homes “offer an opportunity to produce your own food.” Their project had an indoor “greenhouse wall shelter” for growing herbs and seedlings that could be moved outside to the garden plot once they grow larger. “The local food movement is part of living sustainably.” The team from the University of Illinois at Urbana-Champaign also added an edible garden around the exterior of their home.


Parsons The New School of Design and Stevens Institute of Technology worked with Habitat for Humanity to create a real home that will be turned over to a family in the Deanwood neighborhood of Washington, D.C. once the competition is over. Parsons said the family was actually brought into the design process early on and they requested a rooftop food garden, which will be accessible via the second floor of the home. One fun element was a Parsons-designed cookbook offering recipes for the foods grown in the home. In addition, their home is designed to have zero stormwater runoff: a rain “spigot,” which funnels water into a rain garden, captures any stormwater coming off the roof. Any excess runoff will be stored in a 2,000 gallon tank buried under the house and then reused for irrigating the landscape. Eventually, when the home is put in place in Deanwood, two bioswales will be installed at either ends of the house to capture stormwater. Their project is also designed using PassiveHaus technologies, including extra thick walls and glazed windows.

Victoria University of Wellington, which is representing New Zealand in the competition, elegantly integrated a range of New Zealand landscapes into the form of their home. As visitors enter the house, they “begin at the beach,” with a landscape of grasses and sand-binding plants that “mimics the New Zealand coastal landscape.” Further in, around the home, there are a “mosaic of shrub land,” here innovatively incorporated into plots around bench seating. Behind the house, there’s a “forest edge” that replicates the “conifer-broadleaf forest which the most complex and diverse in New Zealand.”


Lastly, there are alpine zones featuring “unique flora” and another productive landscape offering opportunities for growing herbs, veggies, and fruits. The landscape provides water efficiency and stormwater management value.


Team New York from the City College of  New York came up with another unique approach that uses 30 percent less water than the conventional home: Shower and sink wastewater is recycled and reused. Also, some 30,000 gallons of rainwater will be captured via external banks of native plants that a landscape architecture faculty advisor helped select and install. New York’s project is designed to be placed on top of the roof of an existing New York City building in an effort to “increase density and encourage car-free living.” This approach is made possible by a “dunnage” system that distributes load through steel beams. The idea is to then plant a green roof around the rooftop home that will function as a yard and garden.


Innovative use of materials, including non-conventional materials and building waste, was another big theme running through the homes. The best example of this was the team from Appalachia State University, which beautifully reused corrugated iron as siding and internal walls, along with a natural, locally-sourced bark siding that is “soaked, flattened, and then kiln-dried” into sheets that last up to 80 years. One student said the bark is a “by product of the lumber industry.” Very smart reuse of a little-considered material.


Explore the 20 teams on the National Mall this year. In 2009, more than 300,000 visited the Decathlon in 10 days. Get there early this year to avoid long lines.

Image credits: Krista Sharp / ASLA