Plus energy quarter made of wooden modules in Bad Cannstatt - record material and CO2 savings!

ARCHITECTURE

Innovative, sustainable, modular! Germany's largest residential project in sustainable timber modular construction comprises 330 apartments for the employees of the Klinikum Stuttgart. This lighthouse project combines an architecturally sophisticated concept, high design, structural and functional quality with the aspiration to create sustainable, affordable and livable living space. The Plus-Energy-Quarter generates more energy from renewable sources on an annual average than it consumes itself and was built with a minimum of material expenditure using serially manufactured wooden modules.

SUSTAINABILITY

At the Klinikum Stuttgart, urgently needed, affordable and at the same time modern living space for employees* is being created in the immediate vicinity of the workplace. The innovative and lightweight modular timber frame construction method was able to save 75% in material mass compared to a conventionally constructed building. The total weight of the wooden buildings could thus be reduced to 1/6 - the associated CO2 reduction is considerable. The wooden modules are completely degradable and can be separated by type. Used materials can be recycled to 98%, 82% of which can be reused without additional processing. They can be returned to biological or technical cycles.

REGENERATIVE ENERGY CONCEPT

On an annual average, the Plus Energy Quarter generates more energy from renewable sources than it requires. In order to implement the buildings in the KfW-40-Plus standard, the most efficient heating system possible was developed based on brine-to-water heat pumps, photovoltaic modules and solar hybrid collectors. Additional heat pumps on the roofs ensure heat recovery from exhaust air and minimal energy loss. The roofs of all buildings are covered with PVT collectors, and the south facades of four buildings are also equipped with facade-integrated PV modules to maximize energy harvesting. Battery storage is part of the energy system.

WOOD MODULE CONSTRUCTION

The six buildings of the quarter have been constructed using an ecological and sustainable wood module construction method. The wooden modules used are serially manufactured in the factory and connected to each other at the construction site. This reduces material consumption and waste generation in production and enables end-to-end quality assurance. Due to the innovative modular construction method and the high degree of prefabrication of the wooden modules of up to 95%, it was possible to complete the first construction phase with 157 apartments for the employees of the Klinikum Stuttgart in a record time of six months and to hand it over to the client.

TARGET

The goal was to create an energy-efficient, sustainable and ecological residential quarter with affordable rents for the employees of the hospital in Stuttgart Bad Cannstatt in a short construction period. After an extensive analysis of the operating and maintenance costs, it was determined that in the long term a plus-energy house system would be more economical and sustainable and would protect the residents from rising energy prices in the long term. The entire urban quarter was then planned as a plus-energy quarter. The project on Prießnitzweg thus does not consume more energy in the annual balance sheet than it generates itself from sustainable sources. On the contrary, it even produces more energy than it needs! The supply of the quarter is based on a completely regenerative energy concept. This energy is generated, among other things, by façade-integrated PV modules on the south sides of the four buildings, as well as PV panels on each balcony roof. On the main roofs are the PVT collectors which generate not only electricity but also heat and serve as a source for the heat pumps. Exhaust air heat pumps also feed heated exhaust air into the primary loop of the main heat pumps. With the combination of highly efficient serially produced buildings, with high living quality, excellent energy standard and innovative energy concept, we set new standards in affordable housing.

Our goal was to significantly reduce CO2 in production and operation. The timber module construction method in a lightweight timber frame construction contributes to this, because this construction method with timber modules saves 40% of greenhouse gases in production, which would be produced in a conventionally constructed comparable building. Due to the significantly lower loads of the building structures, the concrete/resource consumption for materials and greenhouse gas emissions due to gray energy for the construction of underground parking and basements could be reduced. A full 75% of material mass could be eliminated as a result. Via the building resource passport to the quarter it could be proven that 98.3% of the total material mass of the houses can be recycled. 82.5% of the material mass can even be reused directly without additional processing. The wooden modules used are manufactured in the factory - this reduces material consumption and waste generation in production and enables end-to-end quality assurance. Almost all raw materials come from sustainable sources. This construction method has cut the construction time in half, as the production of the residential modules takes place on site in parallel with the construction of the basements. It also reduces noise and dirt pollution at the construction site, which meant that the regular operations of the adjacent hospital were not disrupted. The neighborhood thus consumes a minimum of our finite resources, is durable and fully recyclable. It also generates no CO2 emissions during operation. The Quartier is not only sustainable, but also intelligently designed with surplus energy. With the KfW-40-Plus standard, the building envelope made of renewable raw materials minimizes the CO2 footprint, as well as the life cycle costs (ancillary costs including operating costs).

CHALLENGE OF URBAN DEVELOPMENT

The new residential space to be created is carefully integrated into the existing urban structures in Bad Cannstatt. The new residential buildings, with their invitingly designed green zone for neighborly encounters, connect the hospital park to the north of the construction site with the "Galgenberg" green area to the east, which is important for the climate. At night, the cooling fresh air from the Galgenberg flows through the green zone between the buildings and also ventilates the adjacent neighborhoods. In order to preserve the view from Galgenberg of the Stuttgart city panorama, the buildings were staggered in their height development. The apartment buildings have an east-west orientation, while the buildings with larger apartments for families and residential communities face south towards the diversely designed communal green space. The open space concept includes generous green spaces, playgrounds and meeting areas with seating. The car-free neighborhood is very well connected to public transport.