Impacts of a highly reflective stainless-steel fa?ade on a surrounding building: A case study in Singapore

Few studies have assessed the inter-building direct reflection effect on building daylight and thermal environ-ments with in-depth analysis based on onsite measurements. Therefore, it remains unclear how to quantify this direct reflection effect from field measurement results. To address this issue, this study conducted field mea-surements in a school building in Singapore affected by a surrounding highly reflective stainless-steel facade and proposed a method to quantify the changes in building daylight and thermal environments caused by the reflective facade. Results show that the daylight and thermal environments of the tested classrooms behave differently in the affected period (AP) and non-affected period (NAP) due to the direct reflection effect of the reflective facade. A 1-W/m2 increase in outdoor solar radiation (RS) may cause an additional 0.17-0.74 lux (26%-121%) increase in indoor illuminance (Ig) during the AP compared with the NAP. Moreover, increasing outdoor air temperature (To) by 1 degrees C will cause an additional 0.06-0.51 degrees C (8%-63%), 0.25-0.73 degrees C (27%-69%), and 0.26-0.62 degrees C (39%-87%) increase in the indoor air temperature (Ta), external glass (Tg) and wall (Tw) surface temperatures during the AP, respectively. Furthermore, the impact of the distance between the affected room and the reflective facade (DA-B) on the reflection effect was also evaluated in this study. The main purpose of this study is to display insights we learned from our case study, hoping to raise researchers' attention to the adverse environmental impact of using highly reflective building materials.