Apex are always interested in new and upcoming trends in roofing. Here Jackie Biswell takes a closer look at green roofing – a really hot topic in construction right now.

There is nothing quite like a green oasis in the heart of an urban jungle.

So it stands to reason that architects and town planners are keen to find new and inventive ways of expanding on green space while maximising opportunities for building and development.

Enter green roofing.

What is it?

A green roof or living roof is a roof of a building that is partially or completely covered with vegetation. It may also include additional layers such as a root barrier and drainage and irrigation systems.

Two types of green roof exist: intensive and extensive.

Intensive green roofs are essentially elevated parks and can sustain shrubs, trees, walkways and benches providing irrigation, drainage and root protection layers.

Extensive green roofs however, support native ground cover that requires little maintenance. Extensive green roofs usually exist solely for their environmental benefits and don’t function as accessible rooftop gardens.

Where did it all begin?

Man has used vegetation on roofs since the very first homes were built. Back then it was a primitive form of insulation to keep a house cool in the summer months and warm in the winter.

Famous historic green roofs include the Hanging Gardens of Babylon, one of the Seven Wonders of the Ancient World. These were constructed in 500B.C. and featured a waterproof layer made of tar and reeds, with plants and trees planted above.

The modern green roof was first developed in Germany in the 1960s to try and reduce the problems associated with runoff from impermeable roofs.

These include water pollution, sewers nearing their capacity and localised flooding.

The addition of vegetation absorbs water and slows the run off of any excess water from the roof, reducing the amount stress put on the drainage systems in a city.

Since then, the concept has spread with more and more building designers seeing the merits of their inclusion.

Where is the green roof going?

Recently Livingroofs.org published a green roof market report looking to answer this very question.

It found that while in Germany, about 10% of roofs have been “greened”, here in the UK uptake has been slower.

Investors are starting to recognise the economic potential but the green roof market is still predominantly focused in London where around 42% of all UK green roofs have been delivered.

We think this trend is likely to start spreading out to other counties across the UK in the next decade and are very excited to see the results.

After all, green roofs supplement traditional vegetation without disrupting urban infrastructure.

They reduce energy costs by providing natural insulation, reduce the need for artificial cooling in hot weather, reduce rainwater run-off and provide a range of habitats for wildlife.

They can also create green spaces in urban locations – roof gardens, allotment plots and even park space.

In short, they utilize neglected, unloved and overlooked space and make it useful.