It is not much to look at: a rectangle of rubble and some scrubby weeds, surrounded by the usual building services gear you would expect to find on the top of a modern office block. Yet the roof of Barclays’ 31-storey global headquarters at Canary Wharf, in London’s docklands, sees a steady stream of visitors, from PhD students to property developers, all anxious to study the lessons of the bank’s “living roof. At 160 metres above ground, it claims to be the highest of its type in Europe, perhaps the world.
The roof is not a garden in the conventional sense: the block’s 5,000 Barclays employees are not allowed to eat their lunchtime sandwiches up there. There are no protective railings, and visits, which are dependent on the weather, are carefully controlled by the bank’s environmental and security staff. Instead, the idea is to attract wildlife, including rare insects and birds.
Barclays’ initiative is just one of the signs of an increasing interest in utilising roof space more effect-ively, particularly in cities. This interest extends from the small-scale domestic “greening” of shed and garage roofs, through to residential roof gardens (for the first time at the Chelsea Flower Show in London this May, roofs will get their own show garden category) and the largest commercial developments.
For companies, the motivation may be to reinforce green creden-tials, to add prestige to a develop-ment and to provide added usable space, all of which increase letting potential. Some are adding their green roofs after the development of the building, as is the case with Barclays, although undoubtedly the ideal route is for the design to be integral to the construction.
Technologies to allow green and living roofs are developing fast. “Building a roof designed for bio-diversity so high up hadn’t been done before,” says Bernie McGinty, head of engineering at Barclays. “We didn’t know whether the soil would simply blow away, or if a truly biodiverse culture could spring up so high above the ground.”
It is early days for the project -this summer will be its second -but the bank says it looks promis-ing. A new Barclays building in the US, on Wilmington’s Christina River, Delaware, is following suit. There, with four inches of soil on the roof, plus specially adapted sedum plants, the aim will be to reduce storm water run-off, to provide insulation and to protect the roofs membrane from ultraviolet rays.
In complete contrast to Barclays’ rubble rectangle is the lush half-acre on the roof of No 1 Poultry, in the City of London. This award-winning garden is one of the great attractions of the Conran restaurant Coq d’Argent, at the top of the building. There are tables under a wisteria- and vine-clad pergola, and even grapevines and crab apple trees for the restaurant’s kitchen. At the apex of the garden is a geometric composition of the greenest turf, lines of clipped box, and stone spheres.
No 1 Poultry’s garden was designed by the internationally renowned Arabella Lennox-Boyd, who numbers Sting and the Queen of Belgium among her clients. She is still visiting Poultry in person, 12 years after the garden’s creation, with secateurs in her pocket, to keep an eye on how the pruning is being done and to check whether any plants need replacing.
Her latest rooftop design has just been completed in Hong Kong, as part of a $2l0m upgrade of the
‘You can go completely wild with a roof garden. Its so artificial – an imaginary world’
Central District’s Landmark complex for Hongkong Land, the property investment, management and development company, which is part of the Jardine Matheson Group. The complex contains retail outlets for an impressive Ust of luxury brands and the first Harvey Nichols store in Asia, as well as the Landmark Mandarin Oriental hotel and the gourmet restaurant L’Atelier de Joel Robuchon.
The roof garden, which is accessed through the restaurant, is part of the “Central Cityscape” scheme, an attempt to add greenery to Hong Kong’s Central District and reinforce the area’s reputation as a glamorous retail destination, says Raymond Chow, executive director of commercial property, Hongkong Land. The Lennox-Boyd design, says Mr Chow, has successfully combined modern and traditional aspects of the Chinese landscape into an urban oasis.
Unlike the Poultry roof garden, which was planned into the building from the start, the Landmark garden has been added during the
building’s upgrade, so there was no provision for considerations such as drainage or waterproofing. Any weight has had to be carefully designed to sit on existing joists. Nevertheless, the garden has a stylised dragon of velvety turf stretching around the garden, slate paving sourced from the UK’s Lake District, stainless steel planters and giant spheres covered in bou-gainvillea.
Despite the technical constraints, Ms Lennox-Boyd finds designing roof gardens strangely liberating. “I love doing them,” she says. “You can go completely wild with a roof garden. It’s so artificial – an imagi-nary world.”
In New York’s TriBeCa district is a building currently under con-struction that takes the concept of a roof garden another stage further. At the 101 Warren Street development an “elevated forest” of 101 pine trees forms an impor¬tant part of the marketing of this luxury residential development. The trees will be lifted in by crane later this year when the building nears completion, and they will sit, with their bases wreathed in mist, on a floor of washed river stone.
Above: the garden at
No 1 Poultry; right Hongkong
Land; and left: the rooftop of
the Barclays headquarters in
London’s Canary Wharf
The building is a contemporary, modernist structure, with paintings and sculptures in the public areas – the developer, Edward Min-skoff, is an art collector.
Tom Balsley, the landscape architect for Warren Street, says the trees chosen are ideally suited to the purity and simplicity of the minimalist design.
Roof gardens are not just there to make a building pretty, he says. They can be small parks, where residents, who might otherwise meet only in the elevator, can socialise.
“These spaces really improve the quality of life for people in the building,” he says. “Thirty years ago I would get kicked out of a room if I suggested a roof garden. Now I can’t find a client who won’t do a roof garden.”