It has been argued that the “green” building has a better indoor environment quality than the conventional building. This concern for the poor indoor environment quality of the building will cause symptoms of “sick building syndrome” and will affect the health of occupants. In addition, energy efficiency is fundamental to attain sustainability in green buildings. But there is no evidence directly showing us that a green building is more comfortable and satisfactory than a conventional building. This research determines the difference in indoor environment quality (IEQ) of both buildings through finding out the parameters of IEQ and testing the occupants' perception and satisfaction. A green building and a conventional building will be targeted, and a list of questionnaires will be given to the occupants to obtain their perception and their satisfaction level. The responses from the occupants of the different buildings will be compared to look into the difference.