The effectiveness of adding horizontal greening and vertical greening to courtyard areas of existing buildings in the hot summer cold winter region of China: A case study for Ningbo.

• The effects of green roofs and practical green façades within courtyard area on public buildings investigated for "Hot Summer, cold Winter" region of China. • Internal surface temperatures for areas with and without external greening monitored and compared. • Heating and cooling energy consumption before and after greening compared from computer simulation as well as from smart meter readings. • Actual heating and cooling energy consumption before and after greening compared using statistical analyses. T -statistics and p -values show significant reductions were achieved. The "Hot Summer Cold Winter" climate region of China is one of the most challenging regions for providing occupant comfort in buildings, with high demands for heating as well as cooling, together with high humidity levels. Although the performance of buildings has improved with the implementation of the new Chinese National Building Standards for the Zhejiang Province, it is believed that adding passive strategies could help to alleviate the problem even further. This paper aims to investigate the effects of adding horizontal greening (green roof) and vertical greening in the courtyard area to existing public buildings in the "Hot Summer Cold Winter" climate region of China. Using computer simulation and measurements from a monitored case in the city of Ningbo, the effects of green retrofitting on human comfort and energy consumption are analysed. Simulation results suggest that with partial horizontal and vertical greening, the cooling load could be reduced by 8.8% and heating load by 1.85%. Comparisons between actual energy use before and after greening on the case building showed significant reductions in both winter and summer, confirming the positive effects of vertical and horizontal greening of public buildings in this region. [ABSTRACT FROM AUTHOR]