I'm standing in a small patch of neglected land in a quiet corner of Clapham, south London. A tiny urban wilderness of creeper, brambles and bracken, ignored by humanity, it is home to robins, foxes, squirrels and innumerable scurrying invertebrates. The horizontal extent of the plot is less than 150 square metres, but it is dominated by the vertical presence of a mature multi-stemmed sycamore, a towering structure that reaches up and out to the sky. Here, on a bright August day, the overgrown plot is transformed by the ever-changing light in the tree canopy and the gentle sway of the branches in the breeze.
The biodiversity of the smallest patch of land is dramatically improved by a tree. Recent research by the University of Sheffield into the density of bugs in urban gardens found that planting a tree is one of the best ways to encourage local wildlife, especially invertebrates. You are effectively laying the foundations for a grand condominium of urban flora and fauna, a luxury habitat that protects its tenants from the ravages of the elements and provides them with a rich supply of nutrients. Everyone benefits, from the beetles that burrow in its bark to the millipedes that forage in the decaying organic matter at its base.
Rather different foundations are planned for this plot, however: deep shafts of concrete, driven into the untouched earth. For this little patch of ground, never built on in modern times, is now a building plot with full planning permission for a three-storey house. Any day now the piling rig will arrive and the local ecosystem will be ripped up. I have set this process in motion, but the house that will rise here will be reflected a million-fold across the country as the Government embarks on its giant leap to overcome the housing crisis.
The Government describes its building programme as creating "sustainable communities". Yet it is fairly obvious that building is still far from sustainable. Not only does house-building destroy local wildlife habitats, it also consumes natural resources and creates little engines of ongoing consumption, above all of carbon- intensive energy. Buildings account for half of our energy use, houses for about a quarter, so the way they are built and the way they function is critical to the task of tackling climate change and making our world sustainable. Yet current building practice is a long way from "meeting the needs of the present without compromising the ability of future generations to meet their own needs" - the original definition of sustainable development in the 1987 Bruntland Report, Our Common Future. Every new house is a new burden on the environment that future generations may pay for dearly.
There is another way. The house I am planning for our little slice of Clapham will not place any burdens on the future. …