Recent experiments have shown that poor indoor environmental quality (IEQ) in office buildings can reduce the performance of office work by adults. It is thus reasonable to suspect that poor IEQ can also negatively affect the performance of schoolwork by children. It is well documented that IEQ in schools is both inadequate and frequently much worse than in office buildings. Since the performance of school work affects learning, they also imply that improving classroom conditions can have lifelong consequences both for pupils and for society. This is why the School of the Future project takes into account both, the energy efficiency of the school building and the indoor environment, in the research and dissemination work, but even more so in the demonstration buildings. One of the main goals of the demonstration buildings is the improvement of the indoor environment quality (air, daylight, acoustic, thermal comfort) with impact on the pupils' performance to be analysed by short-term measurements and questionnaires. This report forms the basis of the evaluation of the indoor enviroment before and after the refurbishment of the 4 demonstration buildings. However it can be also a useful tool for other similar projects and the assessment of the indoor environment of any school building in Europe.