Plastics

Biodegradable buildings may be wave of the future

PUBLISHED : Monday, 10 December, 2007, 12:00am
UPDATED : Monday, 10 December, 2007, 12:00am

Corn-flour plastic can cut cost and waste, says architect

If Shinya Okuda realises his dream, Hongkongers may one day be living in plastic homes.

The Hong Kong-based Japanese architect has discovered a way to make temporary shelters or even buildings that are completely biodegradable.

The environmentally conscious Mr Okuda, a professional architectural consultant at Chinese University, said the idea would also save money.

He says he came up with the idea of using a thermoplastic material called polylactic acid (PLA) to build temporary constructions such as exhibition booths when he was enjoying a weekend on Tung Ping Chau.

'I saw a lot of plastic bags and rubbish accumulated on the island. Then I thought it would be brilliant if biodegradable materials could be used for making tents, booths and even buildings,' he said.

This would mean they created zero waste material and they would cost less to build than if they were made out of concrete and steel.

Mr Okuda selected biodegradable PLA as the plastic as it breaks down completely in soil in 90 days.

Not only is PLA completely biodegradable but it is made from renewable resources such as corn flour and sugar cane.

The plastic can be moulded into shell-like shapes that require a minimal amount of the material. By joining these plastic shapes together, a cave-like structure can be built.

Although PLA is widely used to make disposable cups and utensils, Mr Okuda is the first to introduce the material to the field of construction and architecture.

He said the material could be used for making temporary structures such as refugee camps during emergencies and holiday tents if the plastic sheet could be made thicker.

'The cost of producing plastic is low and many manufacturers in Foshan , Guangdong, now mass-produce PLA,' he said.

'The difficulty we face is a lack of incentive for these manufactures to invest time and money on research such as mine.

'If we can persuade them to make thicker plastic sheets, smaller-scale construction such as booths can be readily produced.'

In the future, Mr Okuda hopes to design building blocks that are made out of PLA.

But more has to be done in the way of structural testing and refining the characteristics of PLA.

Mr Okuda's green construction idea is featured at the Hong Kong and Shenzhen Bi-City Biennale of Urbanism/Architecture that opened in Shenzhen on Saturday. It will run until March 9.