© 2015 The Authors. Thermal regulation is a key ecosystem service provided by urban plants. In addition to summer cooling, plants can insulate buildings against heat loss in winter. Research was conducted over two winters using replicated small-scale physical models to simulate heat loss from a built structure and to investigate the insulation properties of plants during cold weather. Brick cuboids were constructed around a water tank maintained at 16°C and energy use monitored. Covering cuboids with ivy (Hedera helix) reduced mean energy consumption by 21% compared to bare cuboids during the first winter (means of 4.3 and 5.4kWh per week, respectively). During the second winter, when foliage was more extensive a 37% mean saving was achieved (3.7 compared to 5.9kWh per week). The presence of Hedera enhanced brick temperatures significantly compared to bare walls. Temperature differences were affected by weather parameters, aspect, diurnal time and canopy density. Largest savings in energy due to vegetation were associated with more extreme weather, such as cold temperatures, strong wind or rain. Under such scenarios green façades could increase energy efficiency by 40-50% and enhance wall surface temperatures by 3°C. These empirical studies with replicated treatments augment previous research based on urban modelling and data from non-replicated individual buildings in situ. They indicate that planting design requires more attention to ensure the heat saving aspects associated with green façades and shelter belts are optimised. These aspects are discussed within the context of wider urban ecosystem services provided by vegetation, and implications for climate change mitigation.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)