These houses in Herzogenaurach will generate more energy than they consume.
These houses in Herzogenaurach will generate more energy than they consume.
Sustainability Report

Precision work in construction

On this sunny but cool spring day, these particular row houses in Herzogenaurach, Bavaria, aren't very warm—not yet, at any rate.

Eight families will be moving into these modern brick houses, but not until the end of 2017. Till then, the workmen will have a lot to do. They are wielding their screw-drivers, saws, spatulas, planes, and other tools at many points in the shell structures. These are normal routine activities. Nonetheless, this construction site is very special, because the new buildings are part of a research project at the Technische Hochschule Nürnberg. Evonik is participating in the project. Together with other companies, the partners are planning and constructing innovative energy-storing houses that generate more energy than they consume. It's an unusual project that points out one path to the future of construction.

The heating, hot water provision, and lighting of public and private buildings account for 40 percent of overall energy consumption in Germany. They also represent almost 20 percent of the country's total CO2 emissions. Innovations from companies such as Evonik are making a key contribution to Germany's effort to reach its climate protection targets. For the construction sector, scientists at Evonik have developed an innovative insulation material that significantly boosts buildings' energy efficiency: CALOSTAT®. Evonik launched this high-performance insulation material, which is based on silicon dioxide, on the market three years ago. Building contractors and architects are very interested in this product.

They use CALOSTAT® not only for new buildings such as the ones in Herzogenaurach, where the facing bricks of the shell structures, for example, have been filled with the insulation material, but also for the subsequent thermal insulation of older houses. That's because most older buildings are insulated either inadequately or not at all. Energy-saving renovation can reduce an older building's energy needs by as much as 90 percent.

CALOSTAT® is an insulation material characterized by very low thermal conductivity. That makes this product especially attractive for building renovation in city centers, where houses stand close together and in many cases there's no room to apply thick layers of insulation material. “With our product, the insulation thickness can be reduced by up to 50 percent by comparison with traditional materials—with the same level of insulation,” explains Bettina Gerharz-Kalte, who heads the Thermal Insulation unit at Evonik. A shell structure insulated with CALOSTAT® keeps heat inside the house in winter and outside it in summer. That also reduces air conditioning costs. A further benefit of this high-performance insulation material is that CALOSTAT® is nonflammable and thus fulfills increasingly stringent fire prevention requirements.

But the team of experts that developed CALOSTAT® has set its sights on more than just the purely technical properties of this material. They also consider the needs of customers and users, and they work with partners to develop system solutions. Thanks to a facade panel that can be used to insulate public buildings or high-rises, Evonik was included in the KlimaExpo.NRW exposition in 2016, a climate protection initiative of the state government of North Rhine-Westphalia. This insulation panel makes it possible to save energy in many ways. For example, a building in which it is used as a facade element can reach the passive- house standard, even though the element is only 12 centimeters thick.

“Feedback from our customers and partners is important for the further development of our product,” says Gerharz-Kalte. The impressively small environmental footprint of CALOSTAT® has also made it popular on the market. The insulating material can be recycled without any problems or disposed of as normal construction waste, because it consists almost entirely of mineral raw materials. For CALOSTAT® , Evonik has received the Material Health Certificate in gold from the Cradle to Cradle Product Innovation Institute in the USA.