Trained in building physics and building services, but with a clear interest in the closely related research fields, here at the Eindhoven University of Technology my research and teaching activities are directed to the application of the performance based building approach and use of sustainable energy in the built environment, all with a focus on the indoor environment. Originally the performance assessment related more to simulation (CFD) and experimental work. With energy use of building always in close sight, the current focus also lies in the further exploration of the (long-term) in-use indoor environment performance through objective evaluation (measurements) and its perception by its users (subjective and objective). This knowledge should help us to enable the development of real healthy buildings and in the end serve the individual building user better! At the same time the performance approach also allows us to come up with product innovations! There is still a lot to be gained... In line with this interest and activities I was proud to be president of the successful international Healthy Buildings 2015 Europe conference (http://hb2015-europe.org/), which I recently organized on behalf of ISIAQ and ISIAQ.nl together with a perfect team!I tried to write down my drive for my current and future work in a reflection which you can find in the pdf. Please feel free to contact me and discuss about this!