Fri 1 Jun 2007
A change of scenery
With the drive to go green, the landscaping of new developments has taken on a whole new meaning in recent years. Roger Hunt looks at the growth and implementation of sustainable landscaping.Sustainable landscaping is more than simply creating the right planting; it is about designing landscapes to fit the new ecology created when buildings are constructed. Capable of simultaneously influencing aesthetics, air quality, the well-being of residents and climate modification, this landscape can include food-producing gardens and composting areas.
While such a concept may sound plausible for rural locations, it may seem almost impossible to achieve in an urban environment. Yet, in the centre of Brighton, Sussex, joint developers Crest Nicholson (South East) and BioRegional Quintain are set to create the Brighton One Planet Living Community, an environmentally advanced development of 172 apartments that will occupy a derelict island site close to the railway station.
Nicholas Davies, design and planning director for Crest Nicholson (South East), explains that, as part of the local and sustainable food strategy, residents will be able to grow their own food on site.
"The site footprint is predominantly taken up with the buildings so there are a number of vertical slots on the buildings which are punctuated by what we call sky gardens, which are almost like projecting drawers. These allow light to penetrate into the buildings but they also create a small area where it will be possible to grow edible produce. On the smaller of the two blocks we have roof allotments, which are provided in the form of raised planters on the uppermost level."
In addition, a green wall runs up the side of the smaller block to highlight the building's green credentials and enliven what would be a blank elevation. Green walls can provide shading and insulation and they are incorporated in various ways; in this case a stainless steel tension structure will be attached to the face of the building onto which climbing plants will cling. They will be irrigated using harvested rainwater, which will also provide a sustainable source of irrigation for the roof allotments and sky gardens.
Planting at roof level is becoming increasingly common but, as Chris Shaw, Assael Architecture's implementation director, emphasises, it is important that loadings are kept to a minimum, although a reasonable compromise is generally achieved between weight of garden and size of structure to support it.
"Since the gardens have been artificially created, the plants too need to be somewhat artificial. Plants that are able to survive in semi-arid environments, without regular maintenance, are selected in favour of those that require regular cutting, weeding or watering. Ornamental grasses and sedums are used for such landscapes due to their ability to resist drought and self-seed during dry conditions, creating a fresh growth once water returns."
Controlling rainwater run-off from sites is an essential element in sustainable landscaping. The principle of sustainable drainage systems (SUDS) is that they replicate as closely as possible the natural drainage from a site before development. According to the 'Site handbook for the construction of SUDS', a new publication from CIRIA, "they aim to mimic natural drainage from an undeveloped situation, where rainfall soaks into the ground and saturates soil and vegetation before significant run-off occurs. The systems are designed both to manage the environmental risks resulting from urban run-off and to contribute wherever possible to environmental enhancement".
The important point to note is that the performance and operation of SUDS depends upon careful planning and implementation during the construction phase.
Gavin Payne, senior landscape architect with Nicholas Pearson Associates, emphasises that SUDS need to be tackled in a meaningful way, not only from an operational perspective but also to enhance landscape and ecological habitat.
"It is looking at it from a wider scale, unfortunately that very often doesn't happen. Often this is because landscape architects aren't brought on board at the very inception of a scheme when they can actually provide that type of feedback and let people know about the type of timescales sometimes involved. SUDS need to be seen as both an engineering and landscaping project, you can then add something to the scheme rather than just making it an engineering feature."
SUDS are to be used to huge advantage at The Bridge, a 1,500+ homes development by George Wimpey in the Thames Gateway at Dartford. Good fortune means that the site is blessed with magnificent mature trees that fan out towards the river and these are now providing the bones upon which the urban design is based.
The tree lines create a sense of place and have ecological habitats associated with them so their edges are being used as 'greenways' for people to move about the development. Running alongside are 'blueways', stretches of open water which are part of the SUDS and link with the marshes on the banks of the Thames.
Wayne Hemingway, of Hemingway Design and one of the design team for The Bridge, highlights the way SUDS can be integrated within developments by citing an example in a suburb of Hanover, Germany. "There the water just runs off your house across basically a dip in your lawn and ends up in a bigger dip which runs down beside the streets. More than that, they don't fence anything off in Germany on these developments and even put places to ride your bike down through the water so you splash in it; they encourage play and when it freezes over you see the kids skating on it."
This enjoyment of landscape is a concept that Hemingway is keen to see at The Bridge. He makes the point that that people like to live in an environment overlooking green space where there is water. "If you create a place where people want to live, as the Victorians did by building housing developments around parks and Ebenezer Howard did with the garden cities, you actually create longevity of housing."
Many of the homes at The Bridge will have gardens; those that do not will have access to communal gardens, there will also be allotments and communal growing and composting areas.
Bob Tomlinson, one of the founder directors of Living Villages, a housebuilder aiming to create convivial, eco-friendly neighbourhoods that foster an atmosphere of well-being and belonging, takes the view that the spaces between buildings are the most crucial when creating a living environment.
"A good space will encourage people to linger, talk to each other and create a real community. This in turn leads to car sharing, local commitment, local purchases and the potential of local food growing, which are the real contributors to carbon footprint reduction. For every pound spent on solar panels a similar pound spent on allotments has a much greater environmental impact."
At The Wintles, a Living Villages development at Bishop's Castle in Shropshire, each homeowner has the right to an allotment of 100 square metres and, as a result, many are producing food. In addition, the trees that have been planted now require thinning and this has created a fuel supply for the highly efficient wood-burning stoves that heat each house.
"There is a very important psychological connection there; this business of going out and getting the wood, stacking it up and burning it, puts you very much in touch with your fuel source whereas just flicking the switch on the thermostat doesn't," believes Tomlinson.
Planting is obviously a key aspect of landscaping. At Nicholas Pearson Associates, Payne explains that he tries to use indigenous planting that is not only indigenous to Britain in terms of species but also very often sourced as locally as possible.
"We might, for example, collect seed from local meadows if we want to introduce a wild flower meadow into a particular scheme; in other words you are trying to get the genetic strains down to a very local level. For all sorts of reasons that makes sense, not least in terms of adaptability to the conditions, disease and transport issues. What has to be borne in mind is that there is a relatively long lead in time to allow that type of process to happen. Specialist firms have to go out and collect the seed and then it has to be propagated in sufficient quantity to produce what you need for the scheme. Very often you are talking about two to three years prior to implementation for that process to be carried out effectively."
Topsoils are another area that Payne says should be thought about early on. "Very often soils can be worked with on-site rather than bringing imported topsoil in from elsewhere because you can ameliorate soils with green waste which is sourced locally, perhaps through local authority recycling programmes."
While all this is incredibly positive environmentally, the message is that, as with much else in sustainable landscaping, it requires a little vision and the right people to be brought on board the development team.
First published in Show House Magazine June 2007.
The greatest care has been taken to ensure accuracy but some information contained within this article may have changed since it was first published.
Posted by Roger Hunt
in Assael Architecture, Nicholas Pearson Associates, Sustainability on Fri 1 Jun 2007
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