Atrium and its adjoining spaces: a study of the influence of atrium façade design

Abstract

Atrium buildings have been unsuccessful in utilizing available daylight in spaces adjoining the atria. Several studies indicate the potential to improve daylight in adjoining spaces through glazing distributions of progressive increase in the amount of openings from the upper to the lower floors in medium-scale atria. The aim of this investigation was to study parametrically the effects of glazing variations in the façade on daylight factors (DFs) in the atrium and its adjoining spaces under overcast sky conditions. Using Ecotect and Radiance, the objective was to provide optimum glazing ratios for a four-sided, top-lit, square atrium building of WI 0.8. Three glazing compositions were evaluated according to the progressive increase in openings. Each composition, presented as curves, comprises five options worth 20, 30, 40, 50 and 60% openings on the top floor with a progressive increase until 100% opening is reached on the ground floor. The study concluded that façade compositions have almost no influence on the lower floor adjoining spaces where more daylight is typically required, but can have significant influence on the top two floors. Having very small windows on the top floor (20%) increases DFs in the adjoining spaces; however, this increase is not significant and compromises light levels on the top two floors. In this study, the option of 60% opening on the top floor, 79% opening on the fourth floor, 92% opening on the third floor, 98% opening on the second floor and 100% opening on the ground floor was recommended, as it increased DFs on the top floors without compromising on DFs on the lower floors.