Everything you need to know about green roofs:

What is are Green Roofs?

A green roof is an extension of a new or existing roof that has:

• A high-quality waterproofing and root-repellent system
• A drainage system
• Filter cloth
• A lightweight growing medium
• Plants

Green-roof systems may be integrated, with drainage layers, filter cloth, growing plants already prepared in movable, interlocking grids. Or each component may be installed separately. Green-roof development involves the creation of "contained" green space on top of a building.

One size does not fit all

No single type of green roof works for all buildings, climates and client needs. Therefore no person will have the same garden roof as another. Garden roofs are categorized as "intensive" or "extensive," based on the depth of growing medium. An extensive roof has 6 inches or less of growing medium. It also has lower weight, plant diversity, costs and maintenance.

An intensive roof has more than six inches of growing medium and tends to have greater plant diversity, as well as higher weight, costs and maintenance.

Energy-cost savings

Green roofs can provide cost savings on heating and cooling. Results vary according to size of the building, the climate and the type of living roof. Typically a 6inch extensive roof reduced heat gains by 95% and heat losses by 26% in comparison to a conventional roof.

Decreasing water runoff

By capturing and temporarily storing water, green roofs can reduce excessive volumes to reduce drain overflow. By reducing peak flows, living roofs also can minimize flooding and erosion damage to buildings.

Wildlife sanctuary

Although they are not intended to be replacements for true natural areas, some green roofs can provide provisions for wildlife. They can be part of a system to complement wildlife habitats within an urban setting.

In highly populated areas, green roofs could represent island habitats or, better yet, steppingstones for wildlife movement. Even in densely populated areas, green roofs can attract birds and beneficial insects such as bees and butterflies.

From roof to table

Growing your own fruit and vegetables on your living roof can be beneficial to our pockets as well as our carbon footprints: it avoids the need to go to the shop when running out of fresh fruit and vegetables which will in turn reduce the need to travel in your car.

Some restaurants find it easier to grow their own vegetables then find a local supplier, as the vegetables are guaranteed to be fresh when it comes to serving up.

Complementing solar panels

The efficiency of crystalline silicon-based solar photovoltaic panels reduces as temperatures increase. A green roof can boost solar-panel efficiency, and the amount of power they produce, by reducing the roof’s surrounding temperature. In turn, solar panels can help protect the green roof from wind damage.

Green walls

There are two main categories of green walls: green facades and living walls. Green facades have plants growing directly on a wall or on specially designed supporting structures. The plant-shoot system grows up the side of the building while being rooted in the ground.

In a living wall, the modular panels often are made of stainless-steel containers, geotextiles, irrigation systems, a growing medium and vegetation. Living walls share many of the benefits of green roofs and also can support urban agriculture or gardening.

Green roof systems come in a variety of shapes and sizes, and overall everyone is a winner. Installation of the living roof is not time consuming nor very costly: the experts will lay a single ply roofing membrane down to stop water penetrating your home, then it is all down to whether you bought one prefabricated or not.