Home Improvement Blog: The Green Roof, closest we can get to a Hobbit hole

What is a green roof?

Green roof refers to a system of roofing that uses plant life for roof covering instead of traditional covering materials. The system of green roofing dates back to the 1960’s but only in recent years it has became a popular alternative to the traditional roofing due to its environmental benefits and savings for heating and cooling. The plants that cover the roof provide an excellent insulation to the building reducing energy consumption significantly.

What makes up a green roof?

Green roofs are always created in several layers which besides plants include a growing medium, filter cloth, drainage, insulation as well as waterproof membrane. The construction of a green rooftop as well as selection of plants for roof covering depends on several factors including the size of the building and the type of the roof. Both flat and slopped roofs are appropriate for green roofing but creation of park-like roof systems remains limited to larger buildings as accommodation of large plants and trees is too heavy for houses and medium-sized buildings.

According to plant selection, there are three main green roof types called intensive, semi-intensive and extensive. Intensive green roofs refer to rooftops that accommodate large plants including trees, full lawn, etc. This type of green roofing requires a significant depth of soil as well as lot of maintenance, similar to maintaining a park or large garden. Semi-intensive green roof involves roof covering with plants of moderate size and requires less maintenance. Extensive green roof is the most convenient of all types of green roof systems and involves roof covering with a thin layer of growing medium and vegetation that requires minimal care and maintenance.

Benefits of a green roof

Green roofs have been shown to reduce the costs for cooling and heating for as much as 50% offering major financial benefits to building owners. Another major advantage is green roofs over conventional roofing is absorption of air pollutants including carbon dioxide by the plants which helps lower the temperatures in the urban area and reduce the heat island effect.

They also act as a natural filter for rainwater which means that they significantly reduce the amount of rain drainage. The plants absorb over 50% of rainwater which would otherwise run into sewage system. The water that is absorbed by the plants on the rooftop then evaporates back into the air. But the benefits of green roof technology do not end in reduction of rainwater.

Green roof systems are extremely durable. It can last as long as 50 years and requires virtually no repairs like many other roofing systems,only a bit of gardening. Green roofs combined with other green technology such as solar thermal collectors and solar photovoltaic panels can further reduce the costs for heating and cooling as well as help combat the global warming.

Not forgetting you'll look like a Hobbit from the Shire!

There is no doubt that green roofs look extremely attractive especially against that awful urban look and combined with the many benefits they certainly do seem to be superior to your average roof of today, already taking most of Europe by storm recently; I won't be surprised if I see little gardens appearing on UK's roofs any time soon!

Photo Credit: Anup Shah

I bid you adieu my dear Sirs and Madams!