“Choosing an environmentally responsible roofing material can be one of the greatest challenges of green building. Roofing materials tend to be expensive, damage- and failure-prone, and often contribute to demolition waste. An option which has long been popular in Europe, and is gaining increasing favor in the United States, is the vegetative-cover, or green, roof. Designing a roof with plant cover has several environmental benefits. It can reduce rooftop temperature, in turn reducing building cooling costs and even preventing urban heat islands. Additionally, green roofs are an important tool in stormwater management, because they prevent runoff. Finally, plant-covered roofs can play a role in providing urban habitat for songbirds and butterflies, and in improving air quality.”

From the U.S. Department of Energy.

So what exactly is a green roof?

Linda Velazquez writes by email that “a traditional roof garden is a roof deck (concrete, wood, etc.) with potted plants in various types of free standing containers,” while green roof is an extension of the existing roof which involves a special root repelling membrane, a drainage system, a lightweight growing medium, and plants.

“All the green roof component layers cover the entire roof deck surface. Specifically, the roof deck, insulation, waterproofing membrane(s), root resistant layer, drainage, non-woven filter fabric, engineered soil mix, plants (and sometimes a biodegradable erosion control blanket). So, the entire deck has unimpeded drainage over the entire roof, and the weight of soil and plants is more evenly distributed over the entire roof. And the plants are planted directly into the soil, which in effect, looks like the roof deck.

And there will be a few additional layers (protection, vapor barrier board, etc.) that are applied over an intensive green roof system, as the soil depths are deeper, weights are greater, etc. You can also add architectural accents, like paths, arbors, fountains, etc., but these are built onto the roof deck before the layers are put on the roof deck.”

In an article on green roofs, Katrin Scholz-Barth writes:

There are two distinctly different types of green roofs: intensive and extensive. Intensive green roofs require a minimum of one foot of soil depth to create a more traditional roof garden, with large trees, shrubs and other manicured landscapes. They are multi-layer constructions with elaborate irrigation and drainage systems. Intensive green roofs add considerable load (from 80 to 150 pounds per square foot) to a structure and require intensive maintenance. These roof gardens are, however, designed to be accessible and are used as parks or building amenities.

In contrast, extensive green roofs range from as little as 1 to 5 inches in soil depth. Depending on the soil depth and type of substrate, loads can vary from 15 lbs/sf to 50 lbs/sf. For instance, historic green roofs in Berlin, Germany, built around 1900, weigh about 42 lbs/sf. Extensive green roofs are not designed for public use but can be accessed for routine maintenance walks, generally performed once per year. Extensive green roofs are primarily built for their environmental benefits.

Although everything from earth-bermed [partially underground] houses to balconies with potted plants has conveniently been termed a ‘green roof’ at one point or another, this article strictly defines extensive green roofs as elevated roof surfaces that are entirely covered with a thin soil and vegetation layer. They are not necessarily sod or grass roofs... Additionally, the term eco-roofs is not used in this context because products such as wood shingles are also made of natural, renewable materials, and would thus qualify as an eco-roof.

Green roofs can create recreational space while simultaneously address urban environmental issues like smog, climate change, stormwater management, and energy conservation, though there is the additional upfront expense for builders. Europe is far ahead of the U.S. Green Roofs for Healthy Cities:

“In North America, the benefits of green roof technologies are poorly understood and the market remains immature, despite the efforts of several industry leaders. In Europe however, these technologies have become very well established. This has been the direct result of government legislative and financial support, at both the state and municipal level. Such support recognizes the many tangible and intangible public benefits of green roofs. This support has led to the creation of a vibrant, multi-million dollar market for green roof products and services in Germany, France, Austria and Switzerland among others.”

From City Farmer, Canada’s Office of Urban Agriculture:

“In some parts of Germany, new industrial buildings must have green roofs by law; in Swiss cities, regulations now require new construction to relocate the area of greenspace covered up by the building’s footprint to the rooftop - and even existing buildings, some hundreds of years old, must convert 20% of their roofspace to pasture.”

Green roofs also cool down urban areas in summer, saving energy. The combination of dark surfaces and less vegetation in cities creates what’s called the heat island effect:

“On warm summer days, the air in urban areas can be 6-8°F hotter than its surrounding areas. Scientists call these cities ‘urban heat islands.’ The higher temperatures in urban heat islands increases air conditioning and raises pollution levels.”

In 1999, Paul Mijksenaar was hired by the New York and New Jersey Port Authority to change the old and confusing wayfinding systems at the La Guardia, JFK, and Newark airports to more user-friendly systems. His Amsterdam-based firm, Bureau Mijksenaar, is responsible for the signs at Schiphol Airport in the Netherlands, which is consistently rated by travelers as the most well-organized airport in the world. Work for the Port Authority “will ultimately replace more than 5,000 dated and confusing ones, easing the way for some 90 million travelers each year.”

From The New York Times, June 7, 2001:

“His arrival in New York was precipitated by a survey for the Port Authority three years ago by J. D. Power & Associates, a marketing firm. It revealed that among the vast spectrum of bêtes noires at the three major New York airports, getting lost because of confusing directions was second only to unclean restrooms as the most irksome problem.

At Kennedy, for instance, there was no sign telling newcomers how to get to Manhattan. ‘No sign to Manhattan!’ Mr. Mijksenaar recalled. ‘Only to the Van Wyck Expressway! What is this Van Wyck? You didn’t see the word “Manhattan” until the Midtown Tunnel.’...

At the three airports, his mission is daunting: 17 separate terminals with some 300 directional signs each, including signs for garages, airport roads and parking lots. Most terminals are leased to individual airlines with competing agendas and graphics.

The old signs, dating from the early 70’s to late 80’s, almost always had white letters on dark backgrounds, and were indistinguishable from one another. ‘Most airport people don’t have the experience of clients,’ he said. ‘Their solution was to put up more signs and more signs and more signs. So it ended up being a contradictory mess.’...

The new designs are backlit and color-coded into three different modes that peg color contrast to urgency: black letters on bright yellow for “flying mode, the panic mode, the most nervous mode,” used to direct passengers to the gate and from the plane to their baggage; white letters on green for exits, the “the ‘I want to go home’ mode” (based on the color of American road signs); and yellow letters on dark gray, the “waiting mode, the time-to-kill mode,” directing travelers to the restrooms and shopping areas.

Eliminating jargon was [also] a major part of his New York mandate. He replaced the words ‘courtesy van,’ for instance, with ‘free hotel shuttle,’ ‘because that’s what it is,’ he said. ‘Long term’ and ‘short term’ parking were replaced with ‘daily’ and ‘hourly.’ Information areas are now marked with a double pictogram that combines the question mark typically used in the United States with the ‘i’ used in Europe, resulting in a rather existential new sign: ‘i?’...

Mr. Mijksenaar sometimes finds himself at odds with architects. ‘Architects fear visual clutter,’ he said. ‘So there will always be some tension. They think their buildings should speak for themselves. But how can you find a restroom that speaks for itself?’...

In 1963, while Mr. Mijksenaar was an art student at Gerrit Rietveld Academy in Amsterdam, the British highway authority introduced road signs that offered elegantly simple depictions of complex roundabouts. ‘It was a shock for me that road signs could be nice and good-looking,’ he said. ‘Most people think that road signs... are made by civil servants, not designers. That was a real eye-opener.’

Mr. Mijksenaar, now a professor at Delft University of Technology, designed the signs for Schiphol Airport in 1991. Other public spaces bearing his mark are the subways in Amsterdam and Rotterdam, and the Dutch railway, Nederlandse Spoorwegen. He is currently redesigning immigration identity forms, with pictograms that eliminate language barriers, and is studying the ‘tax form of the future’ for the Dutch government.”

Europeans may share familiarity with a common pictogram vocabulary, but as suggested above by the use of the two different symbols for ‘information,’ it remains to be seen how well the imigration form graphics will ‘eliminate language barriers.’ As with any language, systems of symbols must be learned.

Thanks to Stephanie for the heads up.

“I make satirical paintings of bureaucrats and political figures the old-fashioned way: oil paint on canvas. I then transform the paintings into thousands of street posters generated through a offset litho process. Basically I poke fun of ugly old men in suits and ties, like members of the Reagan administration and his cabinet who were abusing their power in the name of representative democracy....

Guerrilla volunteers plaster them onto construction site walls and other surfaces in major cities across the U.S. These poster-plasterings are midnight raids: non-sanctioned, nonscheduled rock-n-roll-garage-band-total-loss poster tours. The volunteers meet in the middle of the night in an all-night coffee shop and plaster my posters all around the streets to surprise people on their morning commute. The posters provide commuters ‘info-tainment’ about politicians that I feel are abusing their power. This allows me to put art in unexpected spaces....

I feel it is an art way to communicate directly to regular people on the street versus a mediated form of distribution, like showing in art galleries.... I am not trying to change people’s minds about issues important to them, instead I try to get people to think along with me and entertain them at the same time. It is not rocket science, I simply try to irritate the powers that be as much as possible without having them squash me like the bug that I am. But it’s the visual buzz on the street that I try to create, because my art is for the people who don’t have the power.”

From LA based guerilla poster artist Robbie Conal. Visit his Web site, check the poster archive, and guerrilla postering guide.

“These photographs, which are from a series entitled ‘No Space at All’, were taken in Kyoto during the bubble and post-bubble eras of the last decade. They document spaces in the city that are defined by concrete, asphalt, cars, metal or chain-link fencing and the absence of what once occupied them — usually an old house or traditional Kyoto machiya. These spaces, which more often than not are used as parking lots to accommodate the growing number of cars, are replacing the warmth of traditional Kyoto blocks with a kind of emptiness. Such spaces are rapidly increasing and can be seen in every part of the city. They are now becoming a characteristic feature of Kyoto’s urban landscape.”

Two projects from the Institute for Applied Autonomy:

“GraffitiWriter is a tele-operated field programable robot which employs a custom built array of spray cans to write linear text messages on the ground at a rate of 15 kilometers per hour. The printing process is similar to that of a dot matrix printer. GraffitiWriter can be deployed in any highly controlled space or public event from a remote location.” See also instructions on how to build your own.

“The StreetWriter project expands on the research gained from the successful Robotic GraffitiWriter project. The system consists of a custom built, computer controlled industrial spray painting unit that is built into an extended body cargo van. The vehicle prints text messages onto the pavement in a manner much like a dot-matrix printer. The expanded width of StreetWriter allows for messages and simple graphics that are legible from tall buildings and low flying aircraft and is capable of rendering message that are several hundreds of feet in length.” Lots of pix and videos at both sites.

See also Bike Writing, a project to turn any bicycle into a printing, street writing device that prints as you ride.

“The bike writer incorporates interchangeable rubber stamps into the wheels so that while riding, the user can inscribe text into public space. An ink roller is applied to the wheel through a simple mechanism, which is activated by squeezing the rear break handle. This activity is extremely covert and effective.”

For the exhibition “We Love New York: Mapping Manhattan with Artists and Activists,” the Institute for Applied Autonomy and the Surveillance Camera Players led workshops on surveillance cameras, public space, and civil liberties. Participants then took to the streets to document the city’s surveillance cameras. The findings were mapped onto an 80 foot map of Manhattan. The group also led walking tours of the City. “Participants [moved] through the city in small groups, using handheld devices to document surveillance camera locations. The cameras will be added to the iSEE community database that allows pedestrians to track the ‘path of least surveillance’ between any two points in Manhattan.”

“The worst airport fire in German history occurred on April 11, 1996, when flames broke out in the busy Düsseldorf airport, quickly filling the terminal with acrid, toxic smoke. Travelers frantically looked for exit signs. In the ensuing chaos, 17 people died and 150 were injured. A spokesman for the Düsseldorf fire brigade, quoted in European news accounts, blamed the high number of casualties on passengers ‘ignoring’ emergency exit signs. For airport management, having the signage singled out as a contributor to the disaster underscored the importance of maintaining a clear communications system in a crowded, public space. Prior to the fire, signage at Düsseldorf had become a clutter of airline logos and retail and service ads, with directional signs lost in the cacophony.”

Traveler safety and ease of movement were key considerations, along with establishing a distinct identity for the airport. The design from MetaDesign pegged levels of the importance of information to the levels of color and contrast, designing for legibility during normal visbility as well as in a smokey environment. As for non-disaster usability? “Over the past year, the airport information counter reports a 50% drop in inquiries.” Sample pix: before and after. From @issue, volume 3, number 2.

“As a young man more than 35 years ago, Jean-Claude Decaux made a living posting bills on buildings around Paris. His modest livelihood came to an abrupt halt after the local government declared this practice illegal. That’s when Decaux came up with a better idea — one that would allow him to continue posting bills and do it in a way that would contribute to the quality of life and beauty ofthe city. Decaux’s inspiration came one stormy day when he noticed people getting soaked while waiting for a city bus to come by. Why not offer to build bus shelters for free in exchange for the right to sell advertising on them, Decaux thought. He took his proposal to the Mayor of Lyon and got permission to go ahead. That rainy day marked the start of the world’s largest street furniture company.... Over the years, the company has expanded its street furniture offerings from bus shelters and kiosks to news racks, traffic signage, light posts, litterbins, benches, interactive information panels and automatic public toilets.”

Through growth and aquisiton, the company now reached 31 countries and more than 11,000 cities in 1999. Driven by advertising sales, its revenues are in the billions.

“JCDecaux sees its role as designing what French architect Jean-Michel Wilmotte calls a city’s ‘interior architecture,’ deserving of ‘as much thought as that given to private spaces.’ It believes that bus shelters, kiosks and other street furniture are too integral to the urban landscape to be built without attention to aesthetics.”

The company adapts its designs to the character of each city and has recruited several blue ribbon designers and architects to contribute designs.

“JCDecaux has even adapted Paris’ renowned Morris kiosk [picture] into a variety of historic and contemporary styles.... Through technological innovations developed by the company’s extensive R&D arm, many JCDecaux advertising kiosks now integrate newsstands, bottle banks, water fountains, telephone booths, clocks, automatic public toilets, ticket dispensers, interactive information terminals and even automatic vending machines.... Another company signature is the scrupulous servicing of its facilities, which provides premium value to advertisers who don’t want their messages desecrated by vandals.... More than 3,500 service employees maintain the company’s street furniture worldwide. Any broken glass is replaced within 24 hours. Graffiti is scoured clean. In places like Amsterdam where graffiti has become a public art form, JCDecaux has equipped its maintenance workers with motorbikes so they can remove it all the faster.”

From @issue, Volume 5, Number 2.

San Francisco’s Boeddeker Park was “designed with safety and security in mind, but in all the wrong ways.” The 2.6-acre park is cut off from the streets by fences and walls, thouch “meant to provide safety instead make the place feel like a cage.” “The main, bench-lined walkway through the park became known as ‘the Gauntlet’ after it was colonized by drug dealers a year or so after the park’s 1985 opening.” In contrast, Harlem’s El Sitio Feliz incorporates “water play, swings, slides and a small picnic pavilion with community gardens, [the site] has become well-known for its creative combination of activities for children and adults. The most popular play equipment is a simple garden hose, which kids use to spray each other and keep the slide slippery. The playground is flanked by community gardens, tended regularly by local residents who seem to enjoy the frequent interaction with children.” Check out Great Public Spaces and the Hall of Shame at Public Buildings & Civic Design, a site with lots of bite-sized case studies brought to you by the Project for Public Spaces, “helping people to grow their public space into vital community places.”

“The Israel—Palestine war is not simply a struggle over territory between two national entities. It is driven by Israel’s systematic denial of modern urban life to the Palestinians. One of the lessons of the battle of Jenin is that the bulldozer that demolishes houses is also a weapon in the wider strategy to prevent the Palestinians from creating a modern, normal, urban society.”

See ‘Clean territory’: urbicide in the West Bank by Stephen Graham on OpenDemocracy.