Rooftop gardens have many advantages. They can help to reduce pollution, maximise space and add natural beauty to a building.
A study conducted by Cardiff University found that rooftop gardens help to fight global warming by combating the urban heat island effect, reducing peak temperatures by as much as 11°C. One of the primary causes of the ‘urban heat island effect’ is due to buildings and roads absorbing heat, which then radiates into its surroundings. This drives up the demand for energy and consequently, costs more money to cool surrounding homes and businesses.
Rooftop gardens counter this problem in two ways. First, when the rooftop vegetation absorbs heat and energy that it needs to grow, it reduces overall warm ambient temperatures of the structure and surroundings. This effect naturally cools the building and thus reduces energy consumption. The plants also cool the air through a process known as ‘evapotranspiration’, where they evaporate water into the air.
The second benefit is reduced energy usage, as the gardens help to decrease the demand for cooling.
Another study made in Switzerland found that rooftop gardens can support small wildlife. The green space can be perfect to create an eco-friendly habitat for a variety of birds, squirrels, and even monkeys (in certain parts of the world). The study in Switzerland alone found 172 different species in 11 green rooftops alone.