Green roofs help to make urban climate milder, especially in case when it is drastically different from climate of the surrounding areas. Walls and roofs of buildings show heat retention properties. This phenomenon is referred to as “urban heat island”. It means that in centers of big agglomerations, the temperature of air rises by approximately 1- 2°C degrees. Sometimes it can even rise by 10°C. At the same time, humidity drops. Therefore, vegetation on green roofs is necessary because it plays an important role in creating something that can be called an “air pillow”. This process takes place because water cumulated in plants evaporates and the sunlight is reflected from their surface. “Air pillow” therefore, means higher humidity and lower temperature. For instance, a roof covered with bituminous mass, in summer heats even up to 60-70°C, and a green roof, on the other hand, only up to 25-40°C. These numbers speak for themselves. Additionally, only 2 centimeters of green layer can retain up to 60% of rainwater. Later, rainwater evaporates so humidity rises. Moreover, green roofs facilitate operation of urban wastewater system. They increase production of oxygen and reduce amount of CO2 in the air. It is extremely interesting that during one year, a green roof with an area of 15 m2 is capable of producing oxygen for as many as 10 people, and at the same time to absorb 10 – 20% of pollutants and gases from air.
Green roofs reduce traffic noise, thanks to reflecting and partially absorbing approx. 20 – 30 dB. Green roofs enable giving space an architectonic shape. Moreover, they create opportunity to hide installation equipment on the roofs. They enable creation of homogenous designs thanks to mixing plants in different parts of a building– starting from indoor plants, plants on terraces or roofs to end with plants on the area surrounding the building. Unique compositions make the property stand out.
Green areas can be regained. As a result, full use of a small lots in city centers is possible without interference in urban master planning.
Green roofs offer an additional protection and thermal isolation of the roof. Roof covering is protected from external damage, such as: damage caused by fowl, by wind and sunlight.