Green Roofs

Why green roofs?

Much more than just a fashionable option, green roofs are a viable ecological advancement, and one that you can expect to see many more of in the coming years. In London, for instance, it is now regulation for buildings of a certain size to have a green roof installed.

Green roofs can be created in a variety of shapes and sizes, from micro set-ups on garden sheds to extensive gardens on modern self-build homes.

A great way of offsetting your environmental impact, a planted green roof will offer a more vibrant and refreshing aesthetic than traditional materials such as felt or asphalt.

More Benefits

• Green roofs absorb heat from the sun
• They also absorb CO2
• The plantation absorbs around 70% of rainwater
• They provide a level of insulation and can cool the home in the summertime
• Softens your rooftop and blends buildings in with the natural environment
• Replaces the ecology of the new house (replaces the habitat the house takes away)

Available Grass Roof Systems:

Intensive:

Consisting of a thick layer of soil (5-200mm+), this system is ideal for growing a variety of grasses, herbs, flowers and shrubs. This type of green roof will require access for maintenance purposes, with some homeowners even using it as recreational space.

While they provide valuable habitat for wildlife, they place significant weight on the property requiring substantial roofing structural support. They provide good insulation and better water absorption, but just like a garden, they will need a lot of care.

Suitable plants:

• RHS advises plants that are both sun and wind tolerant.

Semi-Extensive:

These green roofs require a greater depth than the below (100-200mm), but as they are constructed on the same principles, they allow for better plant diversity.

This type of green roof is also relatively low maintenance in comparison to intensive green systems.

Suitable plants include:

• Rudbeckia
• Achillea
• Potentilla
• Armeria
• Dianthus
• Helictotrichon sempervirens
• Stipa tenuissima

Extensive:

Made up of a shallow layer (20-100mm) of planted substrate that grows low, stress-tolerant grass, moss and sedum. These lightweight systems require far less maintenance and care than the Intensive and Semi-Extensive options.

The insulation offered from this system is comparatively low, which means these roofing systems often incorporate conventional insulation into their plans.

These tend to be better suited to pitched structures and will flourish best on a slope of 35° or less.

Suitable plants:

• Mat-forming species of Sedum
• Sempervivum and moss
• Ferns such as Polypodium vulgare
• Asplenium Trichomanes are suitable for dry shady conditions