Sustainable construction on a larger scale

In Stuttgart-Bad Cannstatt, a sustainable urban quarter is being created based on the Active House modules developed and designed by Werner Sobek – the prototype is the modular building B10.

The Efficiency House Plus Quarter planned in Stuttgart-Bad Cannstatt will be a milestone in terms of sustainable and serial construction. With a total of 6 buildings for the staff of the Bad Cannstatt Clinic, it will become the largest wooden house quarter in Germany ever planned by a single investor.

The project was awarded to AH Aktiv-Haus GmbH by Stuttgarter Wohnungs- und Städtebaugesellschaft (SWSG), which stands for architecturally sophisticated, serial modular construction based on the Active House modules developed and designed by Werner Sobek. The basis for this is the Triple Zero principle: a building only requires the energy that it generates itself from sustainable sources (Zero Energy), a building produces no harmful emissions (Zero Emission) and all components are completely returned to technical or biological cycles (Zero Waste).

B10 – the world’s first Active House is the prototype

The prototype designed by Werner Sobek, which fulfils all these requirements for sustainable building and is also characterised by an appealing interior and architectural concept, stood as a research project and experimental housing unit for more than 5 years in Stuttgart’s Weißenhofsiedlung and attracted international attention under the name “B10” – an allusion to the location Bruckmannweg 10. B10 is regarded as the first active house in the world which, thanks to a sophisticated energy concept and a self-learning building control system, generates twice its energy requirements from sustainable sources itself. In the meantime, the experimental building has been transported back to its place of production and rebuilt there within a very short time. The compact module is still considered a showcase project for resource-saving and energy-efficient construction.

Modular prefabrication enables faster construction

The example of B10 already showed that building with prefabricated modules is faster and the living space is ready for occupation in a short time. The residents should also be happy about this. This is because noise and dirt, as with conventional construction on site, are largely avoided. These aspects are particularly advantageous when living space has to be created at short notice. This is also the case with the residential complex in Winnenden, also designed by Werner Sobek, which was planned on the basis of the modular concept of B10 to accommodate 200 people.

Even more extensive planning is now underway in Bad Cannstatt. This is the largest award of a building project for “serial construction” under the GdW framework contract*, which AH Aktiv-Haus was able to win over with the Aktivhaus modules developed and designed by Werner Sobek. A total of 329 apartments are being built in the Prießnitzweg district for employees of the Bad Cannstatt hospital. These apartments are spread over six buildings, each with 4 or 5 storeys. The modular, serial construction method allows for a comparatively fast realisation in two construction phases: The first 157 residential units are planned to be completed as early as spring 2022 – including a large number of micro apartments – and the second construction phase with 172 residential units is to be completed by the end of 2023.

Living value and sustainability

The new quarter should be liveable and sustainable in every respect and meet the KfW 40 Plus Standard. In addition, an annual average energy surplus is to be generated from renewable sources. The planned timber-frame construction method is to use mainly certified timber. Consistent application of the lightweight construction principle will save material. The houses will thus not only serve as CO2 reservoirs through the use of wood as a building material, but will also be distinguished by a significant reduction in their grey emissions compared with conventional construction methods. The plan is to create the most efficient heating system possible based on brine-water heat pumps, photovoltaic modules and solar hybrid collectors. A ventilation system with heat recovery is also planned to support the heating system. Other important aspects that are intended to create a high quality of stay include good lighting, generously designed green and communal areas and a cooling supply of fresh air between the buildings.

*GdW is the central association of the housing industry, which has concluded a framework agreement with the Federal Ministry of the Interior, for Building and Homeland Affairs (BMI) and other member companies on the construction of multi-storey residential buildings, including serial and modular construction with high architectural quality. In this context, an innovative tendering procedure was developed, which was won by nine bidders/bidding consortia, including AH Aktiv-Haus GmbH. The aim is, among other things, to build quickly, cost-effectively and in high quality; the sustainability aspect also plays an important role.