Current fast development of cities causes obsolescence of green areas, which is partly the reason for the rise in temperature within cities, and for the creation of the “urban heat island” effect. In order to limit the heating of the agglomeration, alternative ways of introducing greenery to urban areas should be explored. One of these is the use of green walls on the façades of buildings. The vertical garden affects the air temperature, reducing the temperature on the surface of the heated building; furthermore, green walls improve the aesthetic values of the city, introducing peace into the harsh landscape of modern architecture, and they clean the air of toxins. In the present work, we discuss the problems pertaining to green wall thermals. Tests were run on experimental models during 2016 in Lower Silesia Province at the Agro-Hydrometeorology Observatory Wrocław-Swojec of Wrocław University of Environmental and Life Sciences. The main objective of those tests was to check impact of green walls on the environment and on the temperatures inside green wall. Observations were run on the south elevation on building. Performed tests indicated that plant cover works as isolation on wall. Due to these properties, it is possible to stabilize conditions on the wall behind the green panel. All the measurements were run simultaneously on the green wall, and on the reference model – a wall without plant cover. Comparing both models indicated that the green wall limits heating of the outer part of building, which can hold down variation of temperature inside the building.