The UK government is committed to make a positive contribution in reducing global warming through sustainable development. In a public commitment to this, the previous UK, Government started the ‘Building Schools for Future’ (BSF) programme in 2004, to rebuild or renew every secondary school in UK by 2020. To support sustainability, all new school proposals were required to attain a minimum ‘very good’ rating in the Building Research Establishment Environmental Assessment Method (BREEAM) to qualify for funding. This underlined the significance of BREEAM ratings in identifying minimum sustainability criteria for new school buildings. This paper describes the results of post occupancy evaluation of three BREEAM certified BSF schools where the users reported dissatisfaction with the internal environment. A detailed comparative study of comfort standards highlighted shortcomings within the BREEAM assessment process. In the BREEAM education manual, the factors which are found to have a profound impact on students’ performance (daylight, Indoor air quality and thermal comfort) are included in the health and well-being section but none of them are compulsory to qualify for certification. The assessment is also based on predicted building performance rather than actual. Recommendations are made for the improvement of the BREEAM rating system, to support design teams in identifying achievable targets. The abstract should be state briefly the content, methods and results only. Define abbreviations and acronyms the first time they are used. It should be free from formulae, acronyms and references.