Study project : Improvement of the 9 standard classrooms. Special handicap of the location: noise overload from landing planes on the nearby domestic airport. General shortcoming of public schools: no air treatment/conditioning, only ventilators. Measurements: Replacing the standard windows and doors by well closing and noise damping ones, and keeping them closed as much as possible. Sun shading where needed. Installing a central ventilation system with integrated cooling, heating, dehumidifying and energy recovery unit. Improve the lighting system with energy saving lamps and daylight sensors. Effects: Not only quietness and a steady inside climate with a good O2 level… The expectation is that the improvements can lead to a 15-20% better learning performance of the students. This according to numeral projects and reports from Europe and the US. The project is supposed to become a guiding project on how to refurbish and improve older (school) buildings.