German Home-
page of Annex 36
Homepage of the International Energy Agency
Käthe-Kollwitz-School, Aachen
Address Käthe-Kollwitz-School
Bayernallee 6
52066 Aachen, Germany
Year of construction 1951/1955/1978/1990
Year of renovation 2000- 2003
Total floor area 9600 m²
Number of pupils 2200, 85 teachers
Number of classrooms  
Typical classroom 55 m² for about 20 pupils

The Käthe-Kollwitz-School showed very high heating energy consumptions before the retrofit. Together with poorly insulated exterior surfaces, which resulted in not optimal learning and teaching conditions, and damaged building parts, this lead to the idea of taking part in the German retrofit programme "EnSan" of the Ministry of Economy. All demonstration buildings in the programme have the aim to reduce the primary energy of heating and electricity by 50 % by the retrofit. For Käthe-Kollwitz-School this meant to improve the energy efficiency of the exterior surface and of the heating, ventilation and lighting system.

Retrofit features:
  • Composite thermal insulation system using polystyrene foam on the external walls.
  • Replacement of the windows by wooden/aluminium frames with low-E-coating.
  • Insulation of the top ceiling with cellulose, internal insulation of the walls of the heated cellar,    insulation of the cellar ceiling.
  • Transfer of heating system from gas burners to central district heating system with double duct    system.
  • Installation of a decentral mechanical ventilation system with controlled exhaust air fans.
  • Dimmable energy efficient light tubes with electronic ballasts.
  •   total report as pdf-download in English  

    © 2004
    Fraunhofer Institute for Building Physics