New Marienrealschule: Renovation with Extension, Cham, Germany

New Marienrealschule: Renovation with Extension

The district town in the Upper Palatinate in Eastern Bavaria had two secondary schools, which have now merged. The former landmark "St. Josef" boarding house from 1924 was incorporated into the new church-run school on the Chamer School Hill now called "Marienrealschule". The renovated building also has an extension in towards the North. Teachers and pupils of the former Maristen and Gerhardinger secondary schools moved into their ‘new’ school in fall 2021.

The goal of Transsolar's climate and ventilation concept was to optimize the building design in terms of thermal and visual comfort for the users. The technology used was to be kept to a minimum to keep energy and operating costs low.The classrooms in the new and old buildings now have so-called shaft ventilation via individual exhaust ducts in each room. These join under the roof and discharge centrally in the old building, which is particularly effective because the exhaust shaft there ends far up in the former bell tower. The system is known in Germany as "Berlin ventilation” and is an optimized version. All windows have a motorized upper part to be able to centrally control supply air entering when necessary. This function can be overridden individually in each classroom, which may be important in winter to minimize drafts. In the summer, the night flushing cools down the thermal mass of the classrooms. To properly utilize the effect of night ventilation, at least 60% of the ceiling area is open, i.e. not suspended.

The shaft ventilation works without mechanical support, making use of the Bernoulli effect. So, it is particularly important that the ‘air ducts’ are designed for very low-pressure loss; the target value here was two Pa pressure loss including all built-in parts. The windows are defined with a high light transmission of 70% to exploit the existing daylight potential. Excessive solar radiation in summer is kept out by an external sunshade. User control, which allows individual opening and closing, is also important here.