Zero is Not Enough

Can a building really produce more energy than it consumes?

By Barbra Murray, Contributing Editor

Sustainable development practices, from the recycling of construction site waste to the employment of water conservation measures, are practically commonplace in the U.S. commercial real estate industry. While sustainable development features such as low-flow faucets and Energy Star-rated appliances now have a solid place in the American vernacular, solar architecture, beyond high-performance windows and well-placed overhangs, does not. However, courtesy of the work of German architect and solar energy pioneer Rolf Disch of Rolf Disch Solar Architecture, the sun-centric design concept will certainly become a bright light in the U.S. real estate development industry—eventually.

To say that Disch takes the business of energy-efficiency in design seriously is an understatement. Zero-energy buildings produce an amount of energy equal to the amount they use, but that’s not good enough for the solar energy maverick. “We do more than zero; we have zero-plus in all the projects that we do,” says Dr. Tobias Bube, director of marketing and international relations for Disch, commenting on behalf of the German-speaking Disch. “We don’t do zero, zero is not enough.”

Not only has Disch been a long-time, active proponent of solar architecture, he has taken it to new heights with the development of Plusenergiehaus, or PlusEnergy, a design practice that calls for a property to be supported by 100 percent renewable energy and to generate energy exceeding the total it utilizes. Simply put, the buildings produce more energy than they consume. Naturally, the sun is the central component.

In general, solar design capitalizes on the greatest natural energy resource—the sun—to perhaps the highest degree currently possible. The design method, as described by the U.S. Department of Energy, relies predominantly on a building’s windows, walls and floors to collect, store and distribute solar energy to provide heat in the winter and reduce the impact of the hot sun in the summer. Indeed, it is not a novel idea. In fact, as the agency notes, ancient civilizations incorporated principals of passive solar design. “What is new are building materials, methods and software that can improve the design and integration of passive [and active] solar principles into modern residential structures.” Disch has been in the solar architecture modernization game since the early 1970s.

Photovoltaic panels are just one component of Disch’s PlusEnergy projects, the first of which was the Heliotrope—the architect’s 2,200-square-foot home in Freiburg, Germany, built in 1994. In addition to active solar energy features like photovoltaic panels, Disch’s PlusEnergy properties make use of the sun—and ward it off, when appropriate—through such components as canopied roofs, heat-absorbing windows and glazing and thermal insulation. In 2000, Disch conceived The Schlierberg Solar Settlement, a housing community in Freiburg’s über-green Vauban district. The development features 85,000 square feet of residential space consisting of 50 two- and three-story units and, on the roof of the complex’s Sun Ship office building, nine penthouses. Other high-performing, Disch-designed properties include Bürkle-Bleiche Senior Center Living Center in Emmendingen, which offers 59 independent-living apartments.

If the rest of the world is waiting for advances in solar architecture before fully embracing the practice, they’re wasting time. “We don’t need a lot of new technology or new concepts; it’s all there now, it’s all in the market,” Tobias asserts. “When we started doing these things 20 years ago, we had to invent a lot of the things that we needed, like certain window frames with good insulation, but this is state-of-the art and you can get it—you just have to apply it. The innovation is done and we have to spread it. We just have to apply it.”

There hasn’t been a great deal of action outside of Germany, but the interest is there. Representing Disch Solar Architecture, Bube recently traveled to Mexico and Russia, and he has been asked to share his presentations in China on many occasions. “We all have the same problems,” he explains. “We have climate change. In countries like the U.S. and in Germany, buildings account for almost one-half of energy consumption and we are running out of fossil fuels. Everyone has the same problem, so they’re interested in energy efficiency.”

Bube has also spoken in the U.S. on PlusEnergy. “My impression is that the U.S. is really several years behind the development here in Germany and Switzerland and Austria and Denmark and all these countries where we have done some things [in solar architecture],” he recalls. “I was talking to developers and architects there and they’re discussing things now that we solved 15 years ago. It was very similar to the things that I was talking to people about in Russia. But of course, in the U.S., there are architects who are innovative and who want to do things.”

One of the issues responsible for the delayed reaction in solar architecture is, not surprisingly, money. “I think the problem is the development companies, really. They are rather conservative. They want to try to earn money with the kind of project that they have always done and they don’t want to change that.”

But change is good, and the trail-blazing Disch is hardly finished providing an example to the architectural industry across the globe. “Sooner or later residents will want more, even the developers will, because nobody can afford the energy costs anymore,” Bube notes. “And also, the prices for the energy technology are going down, so that’s good news.”

The famed architect’s work is not done in Germany, either. “The real problem is not the new buildings; it’s the existing buildings,” Bube says. “We have a refurbishment rate in Germany of one percent, which means we need 100 years until we have done energy optimization for all the buildings that we have, and we don’t have these 100 years. So we have to speed up there.” Rolf Disch and team will speed up, and the rest of us, sooner or later, will follow.

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