If eco-architect Dr Ken Yeang has his way, cities would please even the most ardent nature enthusiasts.
Dr Yeang, who has been in the field for over four decades, wants to see more biodiversity integrated into buildings, where an ecosystem of plants, animals and their physical environment can mingle together.
“In buildings, the only thing that is biological and organic is you, me and the bugs,” said the architect from Hamzah & Yeang, an architectural firm based in Kuala Lumpur, Malaysia. “Many buildings have been ‘de-natured’. Human beings have simplified and fragmented nature,” he added.
During a lecture at the 3rd Annual Green Building Asia conference hosted by events organiser IBC Asia at the Sheraton Hotel in Singapore last week, Dr Yeang advocated bringing biodiversity back to buildings by having a continuous linkage of vegetation connecting the building rooftop, interior and the facade.
In doing so, Dr Yeang said that designers avoid breaking up the ecosystem, enabling species interaction and migration, and thus achieve a better balance between the living and non-living parts of the building.
Some of his early projects from a decade ago featured “step-planters”, stair-like ramps that brought vegetation all the way to the building’s top in a continuous vertical landscape.
One of the first buildings to apply his vertical greenery designs was the IBM plaza in his home country of Malaysia.
Dr Yeang said that enhancing diversity is important to Singapore as the island is located near the equator and has some of the highest levels of biodiversity in the world.
Although biodiversity has not been as high profile as other environmental issues such as climate change, “it is as important as anything else”, he added.
Over the centuries, biodiversity was severely reduced as natural habitats were destroyed to make way for urbanisation. In 1992, 168 countries worldwide, including Singapore, signed the Convention on Biological Diversity, pledging to support the conservation of biological diversity.
The past decade also saw Singaporeans increasingly conscious of the country’s biodiversity and natural heritage. In 2001, concerned citizens succeeded in forestalling reclamation works on Chek Jawa, a wetland on the offshore island of Pulau Ubin that is rich in biodiversity.
In 2010, Singapore launched its Singapore Index on Cities’ Biodiversity, a tool adopted by over 30 cities to measure conservation efforts and identify areas for improvement.
Planners have been listening; new guidelines on biodiversity from Singapore’s Building and Construction Authority are changing the way neighbourhoods are planned.
Singapore industrial property developer JTC Corporation was awarded last year for its masterplan for the 50 hectare CleanTech Park in the west. Based on a biodiversity impact assessment, the plan contains a green corridor to encourage the free movement of wildlife and a rare tropical freshwater wetland forest.
While landscaping for biodiversity has received significant attention, biodiversity within buildings remains a relatively new concept to Singapore.
Designers of vertical greenery and the surrounding gardens at Singapore’s first eco-precinct, Treelodge@Punggol, tried to preserve some of the Punggol’s biodiversity.
Completed in 2010, the Treelodge eco-precinct is housing agency HDB’s pilot project to create a model eco-town for the 21st century.
Mr Phang Hsueh Terng, vice president of Landscape Architecture for Surbana International Consultants, helped plan the Treelodge project.
At Treelodge, greenery is found on the rooftop, along the walkways, car parks and even the walls of the housing blocks. These are part of the designers’ plan to create a “seamless greenery” in the eco-precinct, said the landscape architect of 15 years.
Mr Phang’s team works closely with biodiversity experts in Singapore to access the state of natural life at Treelodge and the Punggol waterway. They aimed to preserve some of the original vegetation in Punggol, which has largely given way to intense urbanisation in Singapore.
Greenery in buildings in the form of rooftop gardens are slowly taking root in other parts of Singapore.
The National Parks Board started promoting rooftop gardens back in 2002 as part of a national plan to turn Singapore into a City in the Garden.
They also started giving out Skyrise Greenery Awards in 2008 to promote greening efforts in urban developments. The winners of Singapore’s Skyrise Greenery Awards last year include the Hanging Garden in the Central Business District and Helios Residences at Cairnhill Circle.
But buildings with skyrise greenery come with considerable challenges.
The installation of a green wall typically costs between $1,000 to $1,500 per square metre, according to the Board. To help building owners overcome these costs, the Board launched a Skyrise Greenery Incentive Scheme last year to fund up to 50 per cent of installation costs for green roofs and vertical greenery.
The weather is another thing to worry about, said Dr Yeang, as wind speeds up to 30 to 40 metres per second can rip the plants off. While Singapore rarely experiences such strong winds, such a building in Taiwan might require typhoon shelters for protection, he added.
Maintaining urban greenery requires considerable time, effort and money. The National Parks Board’s annual bill for watering, pruning and other maintenance work on urban greenery has jumped from $22.9 million in 1997 to $52.4 million in 2010.
A Straits Times report last year raised the problem of ageing trees in Singapore, highlighting that trees in urban environments are exposed to constant heat, dust and choking fumes, dramatically shortening their lifespan.
Despite the challenges, green roofs are increasingly popular and seen by some as a solution to Singapore’s recurring floods. Last December, prolonged heavy rain caused flooding on some parts of Orchard Road, a major shopping district. An expert panel appointed by the government recently suggested making green roofs mandatory for building owners as a means to slow down rainwater flow.
Ms Shirley Ling, Head of Skyrise Greenery at Singapore’s National Parks Board, estimated that there are about 36 hectares in skyrise greenery in Singapore.
Most of the greenery is built on commercial and private buildings, she said.
Ms Maria Boey, vice pesident of Landscape Architecture for Surbana International Consultants, said that vertical greening of buildings is only “starting to grow”.
“We definitely should make it more popular in Singapore,” said Ms Boey, “It makes our city different and unique.”