Much research and many surveys have shown that building environments have a direct effect upon an occupant’s personal well-being and performance, however, it is only through more recent studies that a clearer understanding of the occupied environment has been discovered. Bako Biro et al. (2008, 2012) have shown that primary school children’s concentration is affected by the CO2 levels between 1000 and 5000 ppm and hence the design for effective fresh air ventilation is vital. Satish et al. (2011) describes research evidence showing that CO2 affects decision making even at levels below 2500 ppm. In the UK, the Building Schools Exhibition and Conference (CIBSE, 1999a) asked head teachers if they felt modern buildings affect learning. Around 78% said they felt there was a clear link between the quality of school design and levels of pupil attainment. Williams (2006) reported a similar conclusion for 12 primary schools which he had assessed using the Building Quality Assessment (BQA) method and comparing the BQA score with examination results. There was a clear correlation between building quality and human performance.