Why climbing plants
Cools Surfaces
Greenery on façades reduces the temperature of the building’s surface itself as well as the air around it. A temperature drop of the façade by as much as 7 to 9 °C is reported, along with cooling of the air in front of the façade by up to 3.3 °C. This is especially important in summer, when urban surfaces overheat and intensify the urban heat island effect.
In addition, trellises or cables create an air gap between the plants and the façade (double-skin green façade = DSGF), which causes the air temperature in this gap to be lower than the temperature of the surrounding air, so the gap acts as a thermal buffer.
Insulating Layer and Better Thermal Comfort
A green façade creates an insulating and, above all, shading layer that reduces direct heating of the wall in summer and helps stabilize temperature fluctuations. With evergreen species, the effect is stronger throughout the year, because the vegetation maintains a certain thermal cushion on the wall even during the colder part of the year. Climbing plants can improve the thermal stability of the space by up to 25% and significantly reduce indoor temperatures during heatwaves.
Saves energy
A cooler façade means less need for air conditioning and often better thermal stability of the building. Climbing plants can save up to 13% of energy thanks to reduced overheating in summer and improved insulation in winter. In older or less insulated buildings, the effect is more pronounced, because the greenery adds an additional barrier against heat flow and solar radiation.
Cooling cities and adapting to heat
Climbing plants help reduce the urban heat island effect because they shade surfaces and, through transpiration, release part of the heat into the surrounding environment. This is especially important during heatwaves in streets, courtyards and on south- or west-facing façades, where surfaces overheat the most.
Over the next twenty years, current estimates predict an increase in average temperature of at least 1 °C and a significant warming of summer days, with city centres potentially being another 2–4 °C warmer than their surroundings – this is precisely why passive cooling measures, such as climbing plants on façades, will be crucial to making life in cities bearable at all.
Facade protection
The common argument that climbing plants damage the facade is not generally true. On a healthy, undamaged facade, they actually act as a protective layer against overheating, UV radiation, rain, graffiti, and minor mechanical stress. Problems may arise with old, cracked, or poorly maintained plaster, where plants can penetrate into gaps and further worsen the damage.
An alternative to trees where there is no space
Climbing plants require very little ground space, so they can be planted even in places where a tree would not be possible due to underground utilities, narrow pavements, lack of soil, or high water demands. Above ground, however, they can create a large leaf area, which means that in densely built-up areas they can partially replace the functions of urban greenery. Their maintenance is many times cheaper and less demanding, and they often only need watering from a gutter or directly from the ground.
Improve acoustics
A green wall improves acoustic comfort. It can reduce noise by 6–8 dB and at the same time provides 41% higher sound absorption than a traditional façade. Even a few decibels make a difference in the city, because noise is perceived logarithmically.
Support of biodiversity
Climbing plants create a refuge for insects, birds, and small organisms, especially in places where there is little other greenery in the city. Even small green areas thus help connect urban vegetation into a more continuous network. This is important for pollinators as well as for the overall ecological stability of the city.
Purifies the air
Climbing plants and green façades act as a natural filter. On an area of 1 m² they can remove 2.3 kg of CO2 per year, produce 1.7 kg of oxygen and capture up to 20% of air pollutants. This is especially important in cities with heavy traffic, dust and overheated streets. Compared to trees, their advantage is that they provide a similar effect even where there is no space for a tree or time to grow one, and in densely built-up areas they complement or partially replace its function.
The leaves capture dust particles, increase relative humidity and improve the local microclimate around the building. This is a simple local benefit that adds up in areas with dense development, courtyards and along pavements.
Aesthetics and Revitalisation of Public Space
Climbing plants can transform grey façades into living surfaces, hide unsightly spots and give streets and courtyards a more pleasant sense of scale. In a city dominated by concrete, asphalt and technical surfaces, a green wall has a calming visual effect and often enhances the perceived quality of the place.
Social, Psychological and Community Benefits
Greenery improves the perception of a place, encourages spending time outdoors and can strengthen people’s relationship to a building, street or courtyard. When a façade becomes a green element, the space feels more welcoming, which can support neighbourly relations, community care and greater interest in public space. In some urban projects, climbing plants are recommended precisely because they help create community green oases even where it is practically impossible to plant trees.
