A garden on your roof? Join the green roof revolution.
Get involved with the living roof renaissance! Did you know that implementing a green roof on your home hosts a whole lot of benefits? From cost cutting energy bills to improving your local wildlife and biodiversity, a living roof can instantly transform your home.
Biodiversity loosely refers to the sheer variety of life in a given habitat. The beauty of the term for me is that it has no beginning or end. All flora and fauna relate to each other to form complex, mutually beneficial networks. Yet human land use patterns, such as mass agriculture and urbanisation continue to disrupt these systems, halting growth and wreaking havoc with finely tuned ecological processes.
Living roofs, often referred to as green roofs, are part of the solution to this, as they not only help to re-establish and strengthen biodiversity but also improve our resilience to climate change and our overall well being. We will explore the impact of greening your roof at various scales, starting small, with the pollinators, invertebrates and plants that co-inhabit the roofs, then scaling up to examine the city as a whole, London being our point in focus.
But first... What exactly are living roofs?
Living roofs provide an additional layer of insulation to your roof in the form of vegetation and substrate (underlying layer), with a whole host of benefits, such as flood management, improving air quality and energy efficiency in your home. They come in many shapes and sizes, but the three main categories are:
Lightweight Extensive - This is the easiest type of green roof to implement as it uses sedum, a light weight and low maintenance plant.
Extensive - This roof uses a combination of sedum and wild flowers. It encourages more wildlife than sedum alone but requires more soil and upkeep.
Semi-intensive - This generally refers to roof gardens. It is high maintenance and requires professional help to implement.
The finer details
Living roofs provide a rare undisturbed habitat for native species and in turn an opportunity to learn about the wildlife in your area. Ecologists in the field are beginning to design roofs that target protected or endangered species such as the Lucanus Cervus Stag beetle or the Red-tailed bumble bee. Pollinators have also been seen drinking from moss on roofs even when a water source is available to them.
Everyone’s living space will be different so first consider what kind of roof you have access to and what your motivations are for having the living roof. It may be your shed, garage or extension that is calling out to be greened. It could be a communal bike shed or even your nearest bus shelter.
No matter where the roof is it will inevitably be pleasing on the eye. It will also retain heat in the building throughout the winter and cool the building in the summer by absorbing sun rays. Green roofs also reduce surface runoff and the risk of flooding, as they absorb water.
Connecting the dots within your community
As we’ve seen, living roofs have many desirable attributes, but like most things, they won’t work as well in isolation. This is a chance to spark up conversation with your neighbours, your local council and MP’s. Perhaps there are initiatives or funding for green roofs in your area. There could be an existing thriving community, who are also interested in retrofitting living roofs. Alternatively people may not be well versed in this area. Regardless, living roofs can connect you with your community, as well as the natural world around you.
London has one of the highest percentages of green spaces per capita in the world, however this doesn’t necessarily equate to biodiversity, as parks are generally composed of monoculture grass and very little wild flower meadows or forested areas. The wildest places in London are often the forgotten ones. Railway lines, cemeteries and derelict brownfield sites are all teaming with life. Greening roofs is one way of connecting these fragmented corridors of biodiversity.
Policy makers, planners and conservationists are beginning to take this seriously and existing living roofs in London are having quantifiable results. A report published by the European Federation of Green Roof and Green Wall Associations (EFB) and Livingroofs.org outlines the benefits and economic values of green infrastructure in London, drawing on a decade of empirical research. The seven main areas of research are:
Surface water management
Health and wellbeing
Potential for carbon sequestration
The report also includes small green roofs, like bike sheds, bus shelters and garages in the statistics, which make up nearly 8% of all the green roofs in London. Again, this demonstrates that even the smallest space can help the movement.
Livingroofs.org are one of the largest independent companies that campaign for urban greening. Their website has some interesting reports, infographics and blogs about green infrastructure in London if you would like to know more.
...More alternatives for renters and flat dwellers
This isn’t just a project for homeowners to get involved with. We have produced a template email to send to landlords, laying out the benefits of living roofs for their properties. For those of you who just know your landlords won’t be interested, this shouldn’t deter you either. We mentioned briefly how bus shelters can be converted into living roofs but roofs aren't the only option.
Have you considered…
seed bombing in local parks
getting involved with local planting schemes
setting up your own growing scheme if you have time