When was the last time you really looked up and considered the city roofscape? For most of us, this space way above eye level is purely functional, the uppermost part of a building that protects us and its contents from exposure to the elements.
However, this roof space could be argued to be one of our most under-used urban assets, with the potential to provide numerous social, economic and environmental benefits. Our quality of life – and indeed the quality of our environment – could be greatly improved by the creation of well-designed, so-called green, brown and recreational roof spaces.
A green roof, as the name suggests, is created when vegetation is grown on a roof structure.This phenomenon is by no means modern – think here of the Hanging Gardens of Babylon and traditional turf-roofed dwellings. These can be seen as the original pioneers of this increasingly popular green trend.
In modern society, where space is at a premium in urban areas, green roofs are perhaps even more environmentally relevant than ever. I am happy to report that this greening design solution is increasingly becoming accepted and welcomed into mainstream design and construction.
The benefits of green roofs are many: kind to both the environment and to the pocket, and they are both beautiful and functional. They are wonderful building insulators and help to regulate temperatures throughout the year, reducing energy consumption and therefore energy bills.
Vegetated roofs can also help to reduce flooding in urban areas by slowing the flow of storm water.
Plants are super-efficient air purifiers and improve air quality by trapping dust particles, absorbing carbon dioxide and releasing oxygen.
Green roofs need to be located in a shade-free area and general topsoil is unsuitable being too heavy and too fertile. Instead, use a shallow and well-drained substrate such as gravel or brick rubble mixed with nutrient-poor soil.
Sedums are one of the most effective plants to grow, as they are capable of withstanding harsh conditions such as strong sun and wind. These small but tough plants thrive on shallow substrate and need no irrigation. They also come in a wonderful array of shapes and colours.
Where there is ease of access to the roof, you could consider a wildflower meadow; not only will this look visually stunning but it will also attract bees and butterflies. Access is required as the meadow will need to be managed and cut down once or twice a year after the wildflowers have self-seeded.
While green roofs are fantastic, a brown roof can be more suitable for use on larger scale industrial or nature reserve rooftops.
This type of roof is created when substrate, local aggregate excavated during construction being the most sustainable source, is moved onto the flat roof, rather than transported to landfill, and plants are allowed to colonise naturally over time.
Brown roofs can help to mitigate and replace the loss of brownfield sites and these high-rise nature reserves provide a habitat for many plants, insects and insectivorous birds like the Black Redstart, an endangered species that requires this type of environmental condition for feeding.
A recreational roof terrace is an open, accessible space that can be used and enjoyed for a wide range of activities that suit your budget, personality and lifestyle. Roof spaces can be dramatic places with breathtaking views of the city and skyscape.
They can provide a recreational space for outdoor eating, growing vegetables, or a hightech, state of the art space with hot tub, fire-pit and outdoor audio and visual entertainment. Whatever your use, a thoughtful and well-designed roof space will really make a difference to your everyday life, and will add economic and environmental value to your property.
The physical, mental and social benefits of direct access to open space are well documented. As our city expands and we live in higher density and closer proximity to our neighbours, we really need to make imaginative use of this asset just above our heads.
Architects and engineers should always be consulted on projects due to issues of planning permission and building regulations. Likewise, I would always advise consulting a professional designer to maximise the potential of your outdoor space.
Whether you have a garage, shed, flat, house, office or factory, why not consider the potential opportunity to develop this roof space into a spectacular ‘living roof place?
Like the lyrics of that well-known song by The Drifters:
I climb way up to the top of the stairs
And all my cares just drift right into space On the roof, it’s peaceful as can he And there the world below can’t bother me…
Gemma Sargant is Senior Designer at Urbanroofgardens Ltd wwvv.urbanroofgardens.com
Garden Confidential Magazine, Issue 2, Summer 2008