An Introduction to Green Roofs
Green roofs (sometimes also called ‘living roofs’) refer to roofs of buildings which are covered with living, growing vegetation, placed on top of a waterproof layer.
Though their renewed use is a relatively recent development in modern architecture, green roofs have in fact been used on dwellings for centuries - sod roofs, for example, were very common in Scandinavia up until the start of the twentieth century.
Although popular and well-established in the United States and continental Europe - above all in Germany, where 10,000,000m² of green roofs are installed every year - green roofs are currently an underexploited roofing solution in the United Kingdom. Nonetheless, their installation is on the rise as more British people, organisations and businesses (and indeed their customers) become conscious of environmental issues.
Green roofs are suitable for use in new build projects, as well as a large range of existing structures, including homes, public buildings and large business premises such as factories and office/tower blocks. In their modern incarnation they can be usefully coupled with other renewable energy technologies, such as solar photovoltaic panels which generate electricity, and solar thermal panels, which are used for heating water.
Green roofs can serve many purposes, such as:
- energy saving in both summer and winter (through their insulating effect)
- the absorption of rainwater
- the absorption of carbon dioxide and pollutants
- improvement of local air quality
- mitigation of the ‘urban heat island’ effect present in large cities (this refers to the higher temperature in urban areas than in rural areas due to human activity - typically around 4°C)
- creation of habitats for fauna
- growing food
- positive aesthetic impact
- sound insulation - green roofs can attenuate the hammering of rainfall (studies have shown that the sound can be reduced by up to 10 decibels)
- use of roof space for leisure activities - some roofs may be suitable for gardens which can be physically accessed
- protection of the roof, which leads to a higher lifespan
The links to the left give you all the information you need to be able to make an informed decision about whether green roofs and walls are right for you.