Post-occupancy evaluation of green buildings: the measured impact of over-glazing

This article presents the findings of research carried out on user response, from external evidence, in highly glazed office buildings and analyses the impact of this on predicting the environmental performance, productivity and energy consumption of office buildings. With high proportions of glazing, there is a significant difference between the theory and actual performance of a building envelope, in particular because of user preferences.

Excessive glazing increases the probability of blinds being operated to reduce the impact of glare or direct sunlight. This significantly reduces the amount of daylight while only marginally reducing excessive heat gains. In the case of buildings in this research, it was found that blinds were extensively used and that artificial lighting was also used to supplement the loss of daylight, even on bright days.

The additional energy used for both cooling and artificial lighting results in high proportions of glazing being responsible for significantly greater energy consumption than predicted and a potential loss in productivity.