Benefits of a Green or Living Roof
There are a number of widely acknowledged benefits to having a green roof, from ecological to financial.
1. Improved Air Quality
By absorbing pollutants from cars and factories, pollen, and dust, the air quality of urban spaces in particular is improved by green or grass roofs.
2. Biodiversity and Wildlife
Grass and Sedum roofs are intrinsically of greater benefit to biodiversity than more traditional roofing methods and are particularly beneficial to insects and bird life, providing more green space and feeding spaces for them.
3. Energy Conservation - Lower Energy Bills
Green roofs are recognised as providing greater thermal performance and insulation for the buildings they are laid on. A green or living roof is essentially a very thick layer of insulation, helping to cool buildings in the summer and to keep heat in in the winter consequently reducing energy costs that would otherwise be incurred doing this artificially.
4. Green space
The urban environment can be very grey and lifeless, especially when seen from above. Green roofs introduce colour and life to the urban environment and improve the overall urban scene, improving the quality of life for those in the vicinity.
6. Urban Heat Island Effect (Albedo effect)
By insulating buildings, cooling roof surfaces and providing plants and a permeable substrate for water to be stored in and to evaporate from, living roofs help to combat the problem of overheating cities during the summer.
7. Noise and sound Insulation
A green roof will provide a high degree of acoustic insulation, reducing the amount of external noise which can be heard inside the building. Sound waves are absorbed, reflected or deflected. The growing medium tends to block lower sound frequencies whilst the plants block higher frequencies.
8. Storm Water Management
One of the causes of the flooding, particularly in recent years, is that when large amounts of rain falls it all runs quickly into storm drains or rivers which then cannot cope. Living roofs soak up huge amounts of water which is then released more slowly into the drainage system or is evaporated back into the atmosphere. In summer green roofs can retain 70-80% of rainfall and in winter they retain between 25-40%
9. Roofing Membranes Last Longer
By blocking UV rays and preventing surface temperature variations which both cause membrane degradation, green roofs increase the life of roof membranes, protecting and extending the life of a roof overall.