Sustainability Spinning: The Heliotrope

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The Heliotrope rises out of the hillside slope and comes into view as we summit the hill.



Another sweatdrop rolled down my forehead, landing softly in the lush grass beneath my feet that carpeted the small hill I now summited. I gazed at the rolling vineyards, which ended only in the dense Black Forest, and, turning, saw my destination, the Heliotrope, rising out of a verdant sea where understory and multistory were indistinguishable.

A canal in Freiburg invites visitors to observe an "alligator" popping his head up (top center) as they stroll leisurely alongside.




I had set out seven hours earlier with two other American students to explore Freiburg, one of the most sustainable cities in the world and certainly a model for German sustainability. Walking through the narrow streets and watching children playing with sailboats in Freiburg’s famous canals, I hardly saw a car; 68% of all trips taken in the city are taken via public transportation (source). After stocking up at a gummy bear store, I entreated my comrades to journey to Vauban, a neighborhood of Freiburg which holds the impressive title of Freiburg’s most sustainable district.  




This is a residential street in Vauban that leads right up to a resident's house and demonstrates the intermingling of vegetation and pathway common across the neighborhood.




Vauban was first developed as a military base in 1937 and then held by the French forces until 1992. Today more than 5000 residents enjoy Vauban’s car-less streets and many parks (source) and walk daily through vegetated paths and around trees to get to their homes, over 100 of which are passive, a type of building style that reduces energy consumption over 90% (source).


It was down one of these overgrown streets that we finally found the Heliotrope, a large cylindrical home with sleek glass windows and supported by a large pole made of spruce timber. This home turns more than just heads though. The roof’s large solar array - accompanied by a roof garden - turns independent of the house to maximize its sun exposure. Meanwhile the whole building turns around its wooden support pole in order to affect heating and cooling; the home’s windows differ in their insulating properties, and the building turns so that the less insulated windows are positioned to face the sun in colder winter months, while the heavily insulated windows are given maximum exposure in hotter months. The home boasts balconies whose railings have thermal collectors to even further increase solar energy production and heat up water for the home’s use. Inside, a spiraling staircase connects the many floors in an open layout which allows you to see the chief building material for the home: wood (unfortunately, we were unable to go inside the home, but you can view it via this video!)

Indeed inside the building many other sustainable features jump out. Garbage and bathroom waste are both composted and sewage water is filtered in a pond in front of the home. Rainwater is collected, filtered, and reused. With all these features, Rolf Disch’s home is CO2-neutral and 100% regenerative. In fact, it produces five times more energy than it consumes (for more information, view here and here)!

This street in Freiburg gives the visitor a sense of how the town does not seek to distinguish "nature" as separate, but rather invites it to be a part of daily life. 

Not all of these environmental features were visible to me as I stood atop that hillside, but the roof alone was enough to convince me I was seeing a Space of Sustainability. The space has another important attribute which to me establishes it formidably as our Space of the Week: its ability to inspire. Disch’s spokesman Tobias Bube recalls the initial days for the Heliotrope when “no German bank would give us a loan. Too expensive, too risky, too crazy” (source), but despite adversity the team set out to prove banks wrong and created a house that has certainly made its money’s worth in reduced energy costs, even making money selling energy back to the grid. It also serves as an example to countless others looking for innovative building techniques and was a forerunner to many other Disch creations, including several passive houses in Vauban.

So there we were, a little sweaty (but well nourished from our gummy bears), enjoying the view and the grass beneath our feet. The Heliotrope in Vauban, Freiburg, is the most sustainable home in the most sustainable district of the most sustainable town in the world’s most sustainable country and our inaugural Space of the Week. Check back Friday for our Face of the Week!


A panorama shot of Freiburg, the town the Heliotrope calls home.