Building our future

Relying on renewable materials in home construction

!The immense heat is still bringing more discomfort to Bangkok with daytime temperatures staying above 35C for more than a month, while the seasonal rain has yet to come to cool down the city. The Songkran festival has already been and gone but many would welcome it back again right now. Currently many of us are realising that air-conditioners can't bring enough cool air for our houses as the outdoor temperatures might be reaching a point where the units are incapable of functioning.

What is to blame? Of course, it is natural but we can't avoid the fact that the country has lost much of its natural forestation. Trees have disappeared from the city and been replaced with concrete structures which absorb heat from the sun to contribute towards what is known as the "urban heat island" effect.

For many years, Thailand has realised that it must keep the natural forests, while buildings made using timber have been replaced by concrete and steel. However, not many are aware that wood is actually a choice of material that is considered renewable, reusable and recyclable. If managed properly, using wood in construction could bring more benefits as the amount of energy called "embodied energy" in the process of manufacturing of concrete and steel can be reduced. And therefore CO2 emissions can be reduced. But if managed inappropriately, using wood could result in more deforestation.

Currently, apart from energy efficiency, the main aim of green buildings is to avoid concrete and steel as much as possible. Scandinavian countries are exporting woods for building construction but with certification to show that they are from managed-growth forests, not natural ones. Japanese housing construction companies are developing a housing prototype which is designed by avoiding concrete and steel. Major materials come from woods and recycled plastic and foam.

A worker extracts Styrofoam from a tatami mat.

A prototype of eco-friendly houses built by Sekisui, a large Japanese housing company, is a good example. I visited the house last month and was surprised to see that it is made of almost 100% recycled and renewable materials. Bamboo has been used extensively for flooring, ceiling and furniture. It is called "Plyboo" or "plywood + bamboo". The Japanese are trying to use bamboo in a variety of ways. Bamboo is considered by most international green building standards as a good source of renewable materials. The term "renewable materials" in construction refers to natural materials which can be reproduced within a period of 10 years. Cotton, hemp and sheep fur are also renewable building materials as they can be used for making fabric and insulation.

Of course, bamboo can be used for building structure, however, it would be nice to recycle waste from old houses and use it to build a new one. The Sekisui house is trying to recycle a material which always causes trouble for disposal _ Styrofoam. This kind of material is not eco-friendly because we still cannot find a way to get rid of it from our planet. Therefore it is smarter to recycle it. Sekisui transforms Styrofoam embedded in the Japanese tatami mat to recycled plastic and uses it to make roof frames. This way, the use of steel can be avoided. When I visited the factory, there were workers who can remove the Styrofoam sheet from a tatami mat within only two minutes!

Sekisui is advancing its research and development on recycled and renewable building materials in a way to save the world from being filled with construction waste. In the near future, we will see a house made completely from the waste of old houses. And more interestingly, a house could be made from any kind of waste from our daily life, even from agricultural waste from food production, and could be run by using energy from waste energy, using water from wastewater, and so on. That is the core concept of eco-friendly houses and we could see zero-carbon buildings in our lifetime.

‘Plyboo’, a new furniture material made of plywood and bamboo.

A table made of bamboo, a good renewable material.

Roof frame made of recycled plastic.

About the author

Writer: Dr Atch Sreshthaputra
Position: Freelance Writer