In 2008 the Government’s Water Strategy for England acknowledged that the below-ground piped systems were insufficient when coping with extreme rainfall and identified the importance of Sustainable Drainage Systems (SUDS) and green roofs, for climate change mitigation and water management.

The Green roofs inclusion within the SUDS strategies have been limited to date however must surely be desirable, as they:

Extend the roofs waterproofing durability

Reduce energy consumption

Provide amenity space

The feasibility of the green roofs within the SUDS strategies shall therefore be evaluated against SUDS design criteria.

1)      Water Quality Improvement by ways of reducing water runoff velocity, filtering pollutants such as nitrogen, copper, zinc, lead and calcium.

2)      Amenity Benefits by ways of providing green space (e.g. roof gardens, communal parkland, areas of recreation and entertainment. Increased access to greener and cleaner spaces is believed to benefit health by reducing blood pressure, and reducing heart rates.

3)      Ecological Enhancements: Almost 90% of England’s population live in approximately 10% of land cover. Habitat lost to urban development therefore lowers species diversity-threatening future food and medicine sources. Whilst not directly replacing habitats green roofs can create compensatory habitat for a variety of flora and fauna.

4)      Hydraulic Performance: Conventional drainage systems typically convey greater and faster run off however green roofs manage storm water more sustainably through the evaporation of rainfall intercepted by the plant surfaces.

Lowering Runoff Volumes…

Long term research from the University of Sheffield, has highlighted has indeed indicated that green roof’s are indeed effective in reducing run off volumes.

Reducing Flood Risk….

The response to extreme events is clearly of most interest in managing flood risk….the green roofs performance in this response was equally noteworthy: Of 30 significant events, a hydrologic benefit was evident for every event, whether this be reducing the run off of water or reducing the volume of water.

With previous research haven been investigated different roof configurations and in different climates, worldwide, divergent results are inevitable. There are also seasonal trends.

The Future?

Hopefully in the future green roofs schemes will feature more prodominantly within SUDS Strategies, as they must recognise the physics-based research of the hydraulic benefits.

Watch more videos on www.greenroofs.com Learn the basics of greenroofs here: what living roofs are, what they do, and how they help solve the most pressing ecological and developmental issues facing the built environment showing projects from around the world.

What are green roofs?

Green roofs or eco-roofs are the modern versions, and have many of the benefits of the ‘sod roofs’ that have been used in Scandinavia for centuries. Green roofs have risen rapidly in popularity, particularly in Germany and the Netherlands, and now in the UK.

There are 2 types of modern green roof systems, intensive and extensive. Intensive green roof systems are generally for heavier landscape constructions on flat roofs, whereas extensive systems can be installed over any deck and contain a number of layers including vapour retarder, insulation and waterproofing membrane layers beneath the vegetation. The general idea is to firstly provide a waterproof layer on a flat roof (or angled up to 45 degrees), and then put a thin layer of living vegetation on top of this.

What is the point of a green roof?

A green roof / eco-roof / living roof as the name suggests, has a more positive environmental and energy efficient impact than a conventional roof. A green roof provides an ecologically friendly space which ‘gives back’ to its environment rather than harming or taking away from it.

Unlike ‘roof gardens’ which are traditionally for city dwellers with no ground level garden space, green roofs are not as ‘heavy’ i.e. they only have a thin layer of vegetation (sedum and mosses). Roof gardens have large amounts of soil and all manner of plants, which in turn means work and maintenance are required throughout the year. Green roofs however are virtually self-sustaining, perhaps requiring some weeding once a year, or an application of slow-release fertiliser.

There are a number of other benefits to green roofs:

Rainfall is trapped in the vegetation and released slowly, thus helping to prevent flooding.

The layer of vegetation acts as natural insulation, thus reducing your heating / energy consumption and bills.

The insulating properties of the vegetation layer also reduce any extremes of temperature inside a building i.e. the sun’s heat is absorbed during the day keeping the inside of the building cool, and this heat is retained at night keeping the building warm.

Green roofs provide a fantastic environment / micro habitat for wildlife e.g. beetles, spiders, birds, bees and butterflies.

A green roof is visually appealing and contributes to a more ‘natural’ looking environment in a built-up area.

How can you get a green roof?

Find a specialist flat roofing company in your area, and ask them for a survey and quote.

What are green roofs?

Green roofs or eco-roofs are the modern versions, and have many of the benefits of the ‘sod roofs’ that have been used in Scandinavia for centuries. Green roofs have risen rapidly in popularity, particularly in Germany and the Netherlands, and now in the UK.

There are 2 types of modern green roof systems, intensive and extensive. Intensive green roof systems are generally for heavier landscape constructions on flat roofs, whereas extensive systems can be installed over any deck and contain a number of layers including vapour retarder, insulation and waterproofing membrane layers beneath the vegetation. The general idea is to firstly provide a waterproof layer on a flat roof (or angled up to 45 degrees), and then put a thin layer of living vegetation on top of this.

What is the point of a green roof?

A green roof / eco-roof / living roof as the name suggests, has a more positive environmental and energy efficient impact than a conventional roof. A green roof provides an ecologically friendly space which ‘gives back’ to its environment rather than harming or taking away from it.

Unlike ‘roof gardens’ which are traditionally for city dwellers with no ground level garden space, green roofs are not as ‘heavy’ i.e. they only have a thin layer of vegetation (sedum and mosses). Roof gardens have large amounts of soil and all manner of plants, which in turn means work and maintenance are required throughout the year. Green roofs however are virtually self-sustaining, perhaps requiring some weeding once a year, or an application of slow-release fertiliser.

There are a number of other benefits to green roofs:

Rainfall is trapped in the vegetation and released slowly, thus helping to prevent flooding.

The layer of vegetation acts as natural insulation, thus reducing your heating / energy consumption and bills.

The insulating properties of the vegetation layer also reduce any extremes of temperature inside a building i.e. the sun’s heat is absorbed during the day keeping the inside of the building cool, and this heat is retained at night keeping the building warm.

Green roofs provide a fantastic environment / micro habitat for wildlife e.g. beetles, spiders, birds, bees and butterflies.

A green roof is visually appealing and contributes to a more ‘natural’ looking environment in a built-up area.

How can you get a green roof?

Find a specialist flat roofing company in your area, and ask them for a survey and quote.