Sedum or green roofing is becoming increasingly popular in Britain and the use of it is becoming widespread as an alternative to traditional materials like slate tiles or felt. A green or living roof is a roof or deck onto which vegetation is intentionally grown or habitats for wildlife are established. There are a number of different types of green roof and each type will look and function in a different way.
Initially, I was very much in favour of sedum or green roofing. I liked the idea that it could lower the use of air conditioning, reduce storm water run-off and provide a home for wildlife. However, after a little bit of research, I realised that the ‘green benefits’ that many people were championing were very much exaggerated.
Claim: Sedum roofs reduce Co2 in the air and emit Oxygen
Reality: Sedums are deliberately slow growing plants so people do not have to weed and mow their roofs all summer long. Consequently they give off little oxygen and take up little Co2.
Solution: By having a normal roof and two small bushes in plant pots either side of the building you will take Co2 from the environment and emit as much if not more oxygen as a sedum roof. Furthermore, there are a number of ornate and attractive plants that are more vigorous than basic bushes, which can also be grown in more sizeable pots next to a studio.
Claim: Sedum roofs reduce the need for/use of air conditioning
Reality: A properly insulated building should not need air conditioning.
Solution: Proper insulation! Unless there is a continual heat source like banks of computers or a lot of large south facing windows then there should be no need for air conditioning in a garden building (in the UK especially). If proper insulation is installed then your garden building should stay warm in the winter and cool in the summer without any need for air conditioning!
Claim: Sedum roofs provide homes for wildlife
Reality: No tree dwelling animals or land based animals can make use of the plants found on a green roof. Only a few insects, spiders and grubs will benefit from such an environment.
Solution: From bird houses to brush shelters, there are many ways that you can help to create habitats for different wildlife in your garden. For ideas and more information check out the RSPB website.
Now as you can see, I am fully in favour of looking after the planet, but I will always argue that there are many more efficient ways of making your garden building environmentally “green” than installing a sedum roof! Nonetheless - if desired - we will be happy to fit a sedum roof on your garden building.
Author: David Fowler