About simulated influence of roof- and wall-greening on an old people’s home in Helsinki, Finland, during the 2018 heatwave event - Drebs, Achim, …

Due to geographical location extended heat-waves occurs in coastal high-latitude areas or cities rather seldom.

In our research we describe influences of roof- and wall-greening on micro-meteorological conditions around (and in?) a moderate insulated stand-alone six-storey concrete building in Helsinki, Finland. The block of flats serves as an old people's home and being built in the late 1970’s, it represents the prevailing construction type of that era. The building is located on a slightly southwards declining slope, and the neighbouring buildings are 30 meters away.

We applied the holistic ENVI-met simulation soft-ware and used real meteorological forcing-data as input for the simulations.  The study focused on a 24-day heat-wave event in summer 2018. During the period from July, 13^th until August, 5^th, the daily maximum air temperature reached almost every day 25 °C and more, sometimes even more than 30 °C. All one-hour air temperature, wind, humidity, and solar radiation (cloudiness) measurements were conducted at a near-by synoptic weather station.

 The ENVI-met soft-ware has standard set-ups for green roof and green wall properties for simulations of their impacts on the thermal condition. We simulated different levels of insulation (poor, moderate, and good) and used the roof- and wall-greening separately or together in order to find the optimal combination of different greening options. Furthermore, we analysed the physical environment around the old people’s home from the aspect of human comfort, especially the influences of the simulated green infrastructures in front of the building.

The research is part of the HEATCLIM-project financed by the Academy of Finland Science Program CLIHE (2020-2023).