From Fish Tank to Facade


Green slime, while still a nuisance in the fish tank, is making its debut in the architecture world as a "smart" building material.

That’s right, millions of microalgae now clad—and energize, shade and help control light in—a new five-story residential building in Hamburg, Germany.

Called the “Bio Intelligence Quotient” house—the €5-million ($6.5 million U.S.) structure is billed as the “first building in the world to have a bioreactor façade as part of an overall regenerative energy concept,” according to the city agency managing the project.

Designed by Splitterwerk Architekten from Graz, Austria, the algae-covered 15-apartment complex is one of 16 buildings planned to demonstrate the city’s commitment to green growth and serve as world models in experimental building and climate change.

The city’s transformation of the industrial Wihelmsburg area is part of the Internationale Bauausstellung (IBA), or “The International Building Exhibition,” a multimillion-euro project funded by the government of Hamburg.

BIQ is a "Smart Material House", a collection of buildings that IBA Hamburg is using in the exhibition to demonstrate new and intelligent materials used in buildings and facades.

Green Facade: How it Works

The Bio Intelligence Quotient house has two different facades, according to project details.

The southwest and southeast facades each contain glass elements covered in crops of microalgae. The algae are cultivated through the supply of sunlight, liquid nutrients and carbon dioxide—a process that produces heat. The microrganisms then produce biomass and warm the building through photosynthesis and solar thermal energy, according to IBA’s website.

The covered “bioreactor facades” create the energy for the building, but also help to control the light and provide shade.

algae facade
SSC GmbH / Dr. Martin Kerner

The bioreacter facade consists of glass elements with microalgae growing in them. The components provide energy and shade.

Because the algae grow steadily, the biomass is in constant movement and the facade changes color, according to IBA organizers.

An aesthetic contrast to the algae facades, the northwest and northeast facades are plastered, according to project details.

“Generous loggias with views form exclusive outdoor areas for each of the 15 apartments, and future occupants will be able to experience the bioreactor facade up close from there,” IBA said.

Hamburg: Model Houses

"The BIQ clearly demonstrates how right the decision was to build 21st-century model houses in line with the International Building Exhibition, and that it makes IBA Hamburg the world leader in experimental house building,” said Uli Hellweg, the managing director of the project.

One of the project’s most “intriguing aspects” was the choice of Hamburg, a city “famous for its long winters and inconsistent summers, as the testing ground for its sunlight-dependent façade,” one local newspaper reported

But Dr. Stefan Hindersin, a biologist with Strategic Science Consult, a firm behind the development of the façade’s technology, rebutted: "It isn’t the best location; it’s even quite bad, if we compare it with southern Europe or the sub-Sahara.

"But, our belief is that if we can get this running in Hamburg, we can do it nearly everywhere.”


Tagged categories: Architecture; Building envelope; Building Envelope; Cladding; Design; Research; Solar energy

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