New construction project De Treffe in Warns (The Netherlands) is a good example of how sustainable energy technology can be applied. In this multifunctional building, two primary schools, a physiotherapist, and an elderly shelter are located. The Topvex air handling units SR04 and SR09 are a logical choice for this project. Firstly, this series of balanced ventilation units is specially designed for offices, shops, schools and daycare centers. Secondly, the Topvex SR has a high efficiency heat recovery with low energy consumption and therefore fits perfectly in this sustainable project.