Jan 19, 2010
Stories by TAN CHENG LI
star2green@thestar.com.my
Crowning glory
 |
|
The seven-storey Keyakizaka Complex in Roppongi Hills, Tokyo, is capped with a rooftop garden that is not only ornamental, but grows vegetables and rice as well.
|
STANDING on one of the streets of Tokyo, visitors will be amazed by the soaring gleaming skyscrapers.
But if you were airborne, you will get a completely different view – many of these highrises are topped with plots of soothing greenery. Tokyo has been sprouting green roofs, alongside green walls, since the launch of its 10-year project for Green Tokyo in 2006.
Like other world metropolis, Tokyo has been – and still is – losing its green pockets to development but it has plans to stem the decline, according to Ken’ichiro Kawabe, director of greenery policy planning in the Tokyo Metropolitan Government.
The rooftop gardens are just one of the many strategies in the plan, the others being turfing of schoolyards, doubling roadside trees to one million by 2015, connecting scattered urban parks with tree-lined road networks and voluntary greening by businesses and organisations.
To restore Tokyo to a city of lush greenery and further curb the urban heat island effect, Kawabe says laws were made more stringent in October: the minimum greenery in a new development site and amount of green roof space were both raised to 25% from the previous 20%. And at least 10% of the original green area must be left intact.
Leading the way, the Metropolitan Government created a 770sqm green roof on the Metropolitan Assembly Building in Shinjuku in 2002. Kawabe says about 15ha of green roof are added to the city annually – that’s about three Tokyo Domes, the city’s 55,000-seat stadium. The city now has 7,358ha of parks.
The greenery ordinance, however, covers only new buildings. “For existing buildings, there are guidelines encouraging greening on walls but this is not mandatory,” he adds.
Rather than the city government leading greening projects, Kawabe says citizens and private businesses are prompted to take an interest in nurturing and protecting greenery, and do so voluntarily. One successful project on “memorial tree”, encourages people to plant a tree to mark important and joyous occasions such as weddings, anniversaries and birthdays. The tree carries the name of the donor and is planted near the Town Hall.
To further drive home green consciousness, the Chiyoda municipality, one of 23 in the metropolis, has produced a booklet, Exploring Our Eco-town – Towards A Low Carbon Society. Sort of a mapped guide to Chiyoda’s eco-spots, it lists almost 40 green initiatives, ranging from solar cell-clad office buildings to wind-powered vending machines, buildings with rooftop and vertical gardens, low-carbon buildings, seasonal food and “eat-local” restaurants, rooftop farms, car-sharing schemes, bicycle-renting projects, second-hand furniture and book stores, solar and wind-powered street lamps, and of course, nature parks.
Eco enclave
Green measures are also being adopted in new urban developments. Roppongi Hills, a 11,000ha integrated development in Minato, Tokyo, by Mori Building Company, is one such site.
“The project is our vision of a vertical garden city,” says Masahiro Takeda of the company’s environmental promotion division. He says about 26.5% of Roppongi Hills is covered in lush greenery and this brings down temperatures.
Tree-lined passageways between buildings further promote ventilation to cool the air. A government survey found the green spaces in Roppongi Hills to be 10°C to 15°C lower than its surroundings.
“To further enhance the landscape, we intend to follow the ecological network system that is used in wild areas, so we plan to have ecological corridors to link green areas within the development,” adds Takeda.
Comprising both residential and commercial buildings, the mixed development cuts down the commute between home and work, thereby reducing carbon dioxide emissions contributed by transportation.
Various green measures have been taken in the development to achieve what Takeda calls a “cyclical society” – from reusing resources in buildings to the efficient use of water through reuse of grey water for flushing and rainwater harvesting which saves 16% of water, recycling old carpets into new ones, setting up waste separation boxes to encourage recycling among tenants, and collecting food waste from restaurants for composting.
The rooftop garden of the seven-storey Keyakizaka Complex, which houses a cinema complex, is not purely ornamental – it also has vegetable and rice plots which supply to local eateries.
Roppongi Hills is also equipped with its own power plant, a natural gas-fuelled cogeneration facility housed in the basement of Mori Tower. Power is produced with natural gas, and the resulting waste heat is tapped for heating and cooling. The plant, owned by Mori Building and Tokyo Gas, meets about 20% of Roppongi Hills’ energy needs and saves it 18% of CO2 emissions.
Such independent power plants which supply energy to the public were allowed after Japan liberalised its energy sector in 1994. This approach gives people a choice. Building developers, for instance, can opt for greener energy sources instead of relying on fossil fuel-generated electricity from the utility.
When the federal government’s carbon cap and trade system is required for large commercial buildings this year, Takeda says Mori Building will be obligated to achieve an 8% reduction in CO2 emissions. Bracing itself for that, the company has in place a carbon management system to gauge energy efficiency in buildings, and possible reductions. Its intelligent energy management system tracks energy usage and pinpoints wastages that can be plugged.
It is also promoting energy conservation among its tenants. “Some 60% of the energy consumed in our development is by our tenants. Which means without their cooperation and understanding, it will be difficult to achieve the 8% goal. So we’ve been holding consultations with our tenants,” says Takeda.
Related Stories:
|