This paper addresses the issue of awareness of Green buildings, Green lifestyle and environmental matters with the aim to depict if GM (Green Mark) rating tool operates in a consumer climate that is knowledgeable. The post-occupancy evaluation of 11 office buildings in Singapore documented a range of performance indicators but also included questions concerning well-being, occupants' expectations, awareness of GM and public expectations. This is augmented with a public survey that asked how GM and Green living are perceived. Over 2200 building occupants are surveyed in the 11 case studies, plus another 315 members of public at various locations across Singapore. Results suggest that although the awareness of Green Mark rating tool was not established well the awareness of Green lifestyle is closely connected to self-reported wellness. The implications and possible effects of raising the awareness of GM on strengthening the GM tool are discussed. Since GM buildings should visibly reflect public expectations, a revision of what GM rewards through its credit structure might be required in the future. In conclusion, the awareness of Green lifestyle is connected to positive mood regarding GM rated buildings and therefore essential for further development and fine-tuning of the GM rating tool. (C) 2015 Elsevier B.V. All rights reserved.