Green facades have a demonstrable impact on how a building and its environment deal with heat and cold. Flemish studies have also tangibly measured these effects on temperature and energy consumption.
What immediately stands out
An en green façade makes the temperature gradient more stable. In summer, the façade heats up less, while in winter it retains heat better. With ground-level façade greenery, maximum temperatures are increased on average by about 2°C lowered. With living wall systems, the difference on hot days can be as much as 8 to 10°C compared to a bare facade.
That temperature damping also increases comfort. Around the building itself, the wind chill can drop by 1.5 to 2°C. This seems limited, but is clearly noticeable in practice, especially on hot days.
In addition, façade greenery plays a role in reducing the heat island effect in cities. In urban environments, it can be up to 10°C warmer than outside. Research shows that more greenery, including façade greenery, helps slow down this effect. An increase of 10% of greenery can already reduce the ambient temperature by about 0.6°C.
Lower energy consumption
The effects are also measurable at building level. Simulations show that a green façade can provide about 6% less energy consumption for heating and up to 11% less for cooling in summer. This is because the facade heats up less due to solar radiation while being better protected from cooling.
However, it is important that the system is constructed and maintained correctly. Factors such as plant density, leaf area and water availability largely determine how strong the effect is. So a well-designed and maintained system performs significantly better.
Sources
ViaVerda (2023). Hygrothermal effects of façade greenery.
Summary report based on Flemish survey (including Green Building, WonderWalls, EcoCities, Total Value Wall and UAntwerpen research).