by ChrisTurner / photographs by Ashley Bristowe
Downtown Freiburg is an accurate approximation of the mental image conjured up by the term “Europe” in your average North American’s imagination: an Altstadt of narrow, cobblestone streets and half-timbered houses encircled by medieval stone gates, footbridges lined with flower boxes over babbling brooks, bakeries and cafés with little circular tables out front lining compact squares.
The traditional highlight of a tour of Freiburg is the Münster, the city’s towering Gothic cathedral, an imposing edifice of spike-crowned buttresses and leering gargoyles in red-brown sandstone that looms over a broad square in the centre of the Altstadt. Completed in 1513 after three centuries of construction, its 381-foot spire testifying to God’s glory and the engineering genius of medieval Europe, the Münster is the quintessence of the high art and refined culture of its time. But I didn’t come all the way to southwestern Germany by intercontinental jumbo jet and superfast train to gawk at another old church.
Instead, I caught the No. 3 tram down on Kaiserstrasse, passing smooth and electric-quiet through the 13th-century gate to a southern suburb called Vauban. Here I found a new landmark, a temple for the worship of both ancient sunlight and hypermodern science: Heliotrop. A house, actually, but some other kind of house entirely: three storeys high and tubular in shape, a sleek glass drum perched upon a stout pole, wrapped in translucent pipe and crowned by a bank of reflective panels. Heliotrop looks like the misplaced centrepiece of a “Homes of the Future” exhibit at the 1939 World’s Fair or a stage set for a live-action version of The Jetsons. The house was completed in 1994 after much less than 300 years’ work by a visionary architect named Rolf Disch, as a place for his family to live and as living proof of his big idea, which he calls das Plusenergiehaus. Which idea, if you can’t parse the Deutsch, is this: the plus-energy house, the house as power plant. Heliotrop then: the first home in Germany – maybe the first anywhere – that produces more energy than it uses.
The name, from the Greek, means “tracking the sun” – heliotropes are plants whose flowers turn toward the sun’s rays. And that, for starters, is what the house does: it spins on its stilt-like perch so that its triple-glazed, light-welcoming glass front can face the warming sun in winter and its sun-blocking, heavily insulated rear can repel it in summer. When supplemental heating is required, a geothermal heat exchanger makes use of the warm ground below, and hot water heating comes from the translucent solar thermal vacuum tubing that snakes around the building (which doubles as balcony rail). The antenna-like protrusion on the home’s roof is a bank of photovoltaic (PV) panels, which convert light from the sun into electricity; these panels rotate independently to maximize their solar exposure, thereby generating something like five to six times this 2,000-square-foot, intensely naturally lit home’s electricity demand. Beyond this, there’s a rainwater catchment system for the washing of dishes and clothes, on-site composting and chemical-free sewage treatment. Greenhouse gas emissions are essentially nil.
Heliotrop’s price tag was one and a half million euros, with some of that coming from the Baden-Württemberg state government. Disch has built two others in Switzerland as “demonstration buildings” (neither of which is lived in) since he finished his own. Which is kind of incidental, because he has already refined his concept for the mass market on a site just up the street, as a sort of gateway to Vauban – quite possibly the first great model suburb of the Anthropocene Era. (Anthropos, from the Greek, means “human”; this term was coined in 2000 to descibe an age whose defining features – namely our climate, atmosphere and ecology – are manmade.)
Sustainable Vauban was born of a transformation nearly as quick as the fall of the Iron Curtain that set the stage for it. Until 1991, Vauban was a French military barracks, a legacy of the Second World War turned Cold War relic. After the French went home, it passed briefly through the German government’s hands to the city of Freiburg, which in 1993 began the launch of an ambitious redevelopment plan for the old barracks blocks. The core of this new neighbourhood is found at the wide, plaza-like intersection where the southbound No. 3 tram makes a hard right off Merzhauser Strasse into the reclaimed military lands, and it’s at this corner where you’ll find Rolf Disch’s more recent designs: Sonnenschiff (sun ship) and Solarsiedlung (solar settlement).
Sonnenschiff is a five-storey, block-long complex lining Merzhauser, tight to the wide sidewalk and tiled in smooth slate grey, its upper-floor windows bracketed by little flashes of pastel cladding like exuberant shutters. As of the overcast spring day in 2006 when I first laid eyes on it, Sonnenschiff’s ground floor was occupied by an organic grocer and a pharmacy, with the far southern bank of storefront windows covered over by a billboard-like display reading ZUKUNFT – “The Future” – in bright red lettering on a white background, like it was the gateway to a new world. Sonnenschiff’s second and third floors are given over to office space, and at the very top, perched on the main building at intervals, are nine two-storey luxury condos. And atop these lies Disch’s signature crown: roofs paved entirely in PV tile. Sonnenschiff is a bit of a laggard by Disch’s astronomically high standards – it produces only about 55% of its energy requirements – but then its main purpose was to bring mixed-use life to the street and provide a visual and aural buffer between the busy boulevard and the cozy car-free neighbourhood tucked behind it.
That neighbourhood is Solarsiedlung: 59 townhouses tightly packed in five neat rows out back of the Sonnenschiff. Each unit is decked out in bright siding – red then yellow, aqua green then vivid primary blue – and each has its own balcony and small patio and wee patch of garden. More importantly, each is hyper-insulated and triple-glazed-windowed and topped in a sloping south-facing bank of solar panels, so that each is, like Disch’s own green home, a net energy producer. Simple and utilitarian. Plusenergiehaus-ing for the masses.
Category: Know-How
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I (and my partner) built that Earthship between 1999-2002 – it is in Taos, NM. We left because of the prevalence of sociopaths in the community. The Earthship was fun but flawed and the community was a living hell! We lost our entire investment and 3 years of our life. I am now getting ready to build a home out of shipping containers – it’s some sort of disease.