Solar Village in Freiburg

New “plus energy homes” in Freiburg, Germany’s Vauban district produce more energy than they use.

Since the 1970’s, the city of Freiburg has taken proactive steps to become an eco-friendly city with an ethic of conservation, environmentally-responsible master planning, and development of alternative energies – especially solar.

In 1992, the city council mandated that all new municipal buildings must be “low energy” buildings employing both passive and active solar components. Freiburg’s green ethic goes all the way to the top; the mayor is a member of Bundnis 90/Die Grunen, Germany’s green party.

The Solarsiedlung, or solar village, designed by Freiburg Architect Rolf Disch, is powered by a rooftop solar panel array. Each home is considered a mini power station. Electricity produced by each home feeds into the existing grid contributing a net surplus of power, thus producing revenue for the homeowner.

Hot water is used for heating as well as domestic purposes and comes from solar heated tubes on the roof of an adjacent business park designed by the same Architect.

In the winter months, an on-site heating plant fueled by wood chips supplements the solar hot water heating system.

Rainwater is gathered and utilized for toilets and irrigation. Catching storm water in an urban context helps relieve pressure on the city’s storm water drainage system.

And in any good green building, a whole array of passive measures have been employed such as sun orientation, sunscreens to shade in the summer and let winter sun in, and triple glazing to reduce heat loss.

Natural ventilation is also an integral feature of this new breed of homes – an eternal concept that works as well now as before the days of advanced mechanical systems.

For more on this development, including Sonnenschiff, the solar powered nearby business park and other green urban projects, see the Architect’s website. A link to projects:

http://www.rolfdisch.de/project.asp?sid=-1411551097

America's Greenest Cities

The results are in.

Portland, Oregon is the greenest city in the United States according to a new study by Popular Science.

Portland scored high on its use of renewable energy, public transportation, green space, and for its abundance of green buildings. Walking and biking in Portland is an option to many inhabitants, improving the health and air quality of the region.

The Top 10 Cities:

Portland, OR
San Francisco, CA
Boston, MA
Oakland, CA
Eugene, OR
Cambridge, MA
Berkeley, CA
Seattle, WA
Chicago, IL
Austin, TX

The study rated cities with populations over 100,000 in four categories to compile the rankings:

Electricity : Cities score points for drawing their energy from renewable sources such as wind, solar, biomass and hydroelectric power, as well as for offering incentives for residents to invest in their own power sources, like roof-mounted solar panels.

Transportation : High scores go to cities whose commuters take public transportation or carpool. Air quality also plays a role.

Green living : Cities earn points for the number of buildings certified by the U.S. Green Building Council, as well as for devoting area to green space, such as public parks and nature preserves.

Recycling and green perspective : This measures how comprehensive a city’s recycling program is (if the city collects old electronics, for example) and how important its citizens consider environmental issues.

For a list of the 50 greenest cities in the United States and to find out what cities are doing in the area of environmental responsibility, see the article. Here’s the link.

http://www.popsci.com/environment/article/2008-02/americas-50-greenest-cities

Green Roofs

Its a jungle up there – or at least it could be.

Green roofs have their advantages according to Chicago’s mayor Richard M. Daley.

"As well as saving building owners money, green roofs…improve the environment and contribute to a healthy city," said Mayor Daley. "These are the kinds of things that improve the quality of life in a city. Our trees, flowers, fountains and benches soften the city's rough edges, add some color and make people feel more at peace with the urban environment."

What is a green roof? In essence, a green roof is composed of indigenous plant life and soil over a waterproof membrane – all on the rooftop of a building.

Environmentally, green roofs offer many benefits. The insulated thermal mass keeps building temperatures warmer in the winter and cooler in the summer. Vegetation in an urban environment counteracts the “heat sink” affect of concrete and asphalt. Green roofs reduce storm water runoff; they clean pollutants from the air and pump additional oxygen into the urban environment.

Functionally, planted roofs lengthen the lifespan of the roof and provide extra patio space for the inhabitants. And urban gardens, including herbs and vegetables, make great use of city rooftops.

Structure must be considered in any green roof adaptation. Smaller plant life takes less soil and can generally be installed on most roofs. Larger trees with bigger root balls should be located above existing structural elements (a column or large beam) so the weight can be transferred to the ground.

A few years ago, Chicago started a grant program (up to $5000) to encourage the installation of green roofs across the city. Chicago City Hall sports a green roof installed by the city in 2001. Since then, the city has saved tens of thousands of dollars on energy costs for this building alone.

Here’s a link for Chicago’s green roof program.

http://www.artic.edu/webspaces/greeninitiatives/greenroofs/main_map.htm

And a link to a site devoted to green roofs.

http://greenroofs.com/

This Week: Green Cities.

Living green in an urban environment.