You may have noticed that more and more buildings are now being constructed with their roofs covered in plants. Known as ‘living roofs’ or more commonly as green roofs, many building owners are now choosing to install them on both new and existing buildings.
Green roofs are not just a new architectural trend, they have been around for thousands of years. In Scandinavian countries layers of turf were laid onto the roofs of buildings to act as a thick insulation or as an alternative to wood.
Settlers in the American Plains in the late 1800s, took it one step further and built houses solely from cut sod pieces. Unfortunately sod houses were prone to leaking and even collapsing on their occupants.
Think your old roof tiles could do with a fresh look, or do you want your house to be eco-friendly? Here are ten good reasons why you, or your office, should consider a green roof.
Extends the lifespan of a roof
A green roof that has been properly installed and maintained should extend the lifespan of a roof 2-3 times its normal life. European roofs can last between 30 and 50 years.
Regulates building temperature
Green walls and roofs can reduce temperature fluctuations of roof surfaces. This can lead to significantly cooler temperatures within a building and lower air conditioning costs.
Reduces Urban Heat Island effect
Plants cool cities during hot summer months and reduce the Urban Heat Island (UHI) effect. They also help reduce the amount of dust in the air.
Captures noise pollution
Hard surfaces reflect sound rather than absorb it. Green roofs can act as a sound insulation, absorbing and reducing noise levels.
Improves office productivity and health
Having a view or access to a green roof, or similar natural vegetation, can increase the productivity and concentration of staff, as well as positive impacts on psychological well-being. There is also a lot of evidence that shows that green spaces can also help sick people recover faster.
Lowers bills and increases building value
Although the addition of a green roof to a building can be relatively expensive (£60-£140 m-2), the benefits given by the green roof should result in financial savings in future, for example by lowering energy bills and roof maintenance costs. The rental value of a building with a green roof has also been shown to be greater than surrounding buildings.
Improves the aesthetics of a building
Depending on their depth of substrate, green roofs can support a wide range of plants, from succulent Sedums, to flowering perennials and even dwarf trees! All of this vegetation improves the look of a building from the outside as well as the inside.
Reduces stormwater runoff
As opposed to conventional roofs which are designed to get rid of rainwater as quickly as possible, green roofs absorb rainfall and keep most of it onsite. This can help to reduce stress on sewer and drainage systems at peak flow periods by ensuring that all the rainwater does not enter the system in one go.
Improves the output of solar PV units
Solar panels and green roofs work perfectly together, even if they are competing for space. German research discovered that solar cells over a green roof had a 6% higher output compared to cells on a bitumen roof, due to the lower air temperatures caused by the vegetation.
Helps urban wildlife
Herbs and perennials to create an alternative habitat for bees, butterflies, insects and birds in urban areas.
So the next time you see some grass peeking out from a roof top, take a moment to appreciate all the wonderful benefits that green roofs provide for us.
If you are thinking about your own green roof or are interested in other vegetation projects on a building, please get in touch with Dr Tom Young at STRI via our enquiry form, email firstname.lastname@example.org or call 01274 565131