Green roofs are not only a visual improvement over traditional flat or shingled roofs, they provide many environmental benefits as well. They are excellent insulators, filter rainwater, and can protect your roof from damage and decay.
A green roof garage, especially in dense downtown areas can also effectively double the size of your green space. That should improve your property value as well!
Reduced Heating and Cooling Costs
Studies show that you could save up to 75% of cooling costs and 25% of heating costs with a green roof. The layers of plants and growing material not only provide additional insulation to the structure beneath, but the respiration of the plants actively cools the surrounding air, helping mitigate the urban heat island effect.
When the outside temperature is 25 to 30°C, a gravel roof can reach 60 to 80°C. Green roofs remain at the same temperature as the outside air, and rooms under a green roof would generally be 3 – 4°C less than that.
Increased Roof Lifespan
Reduced temperature variations and no UV radiation mean that the waterproofing won’t deteriorate over time as it would in a typical roof. You could expect your roof membrane to last 2 to 3 times longer than usual … 50 to 100+ years.
Reduced and Filtered Stormwater Run-Off
A green roof will retain 50 – 75% of summertime precipitation. Any run-off is filtered through the plants and soil, and is therefore delayed, reducing combined sewer overflows. The filtering process also significantly reduces the pollutants present in the run-off.
Filtration of Pollutants out of the Air and Water
A green roof on a typical one-car garage will remove 8 kg of airborne particulates per year and generate enough oxygen to supply 25 people with their yearly requirements.
Sound Insulation
Noise can be reduced by 40 – 50 decibels in a room under a 6 inch deep green roof.
Other Benefits
Green roofs provide additional habitat for birds, butterflies, and other wildlife. They can provide extra amenity space for residents. The environmental benefits are also combined with increased aesthetic appeal … leading to an increased property value.