Wood is the Ultimate "Green" Construction Material
A conversation with Datuk Aaron Ago Dagang, Chairman, Malaysian Timber Council (MTC)
Unfortunately, wood is sometimes under-appreciated by members of the architectural, design and construction fraternity. This issue is exacerbated by misconceptions that wood is not a sophisticated, versatile or durable building material. This is far from the truth as wood is one of the world's top performing construction materials. Tried and tested over centuries, its inherent beauty, strength and durability has seen it remain as one of the favorite choices of building material among many architects and engineers. International Wood asked Datuk Aaron Ago Dagang, Chairman of the Malaysian Timber Council, for his perspective on the ability of wood to meet and exceed today's highest architectural and engineering standards.
"To understand the durability of wood and how it has stood the test of time, one needs to look no further than the Horyuji Temple in Nara, Japan which is officially the world's oldest wooden building," Dagang said. Dendrochronological studies of the wood in that structure have shown that it came from trees felled in AD 594. "Contrary to what modern society believes, wood, applied and maintained correctly can, in fact, outlast other materials such as steel and concrete. Another fine example in Malaysia is a wooden Palace called Seri Menanti in the state of Negeri Sembilan which has stood steady for 105 years and counting!"
WOOD IMPRISONS CARBON, AND MORE
"With the increasing emphasis on 'green' construction or sustainable building, there is a greater need for resources that significantly reduce the carbon footprint of a building, while enhancing the quality and cost-efficiency of a project and ensuring the comfort and safety of its occupants, over the entire lifetime of the building" Dagang said. "As a building material that is renewable, carbon neutral and amenable to advanced engineering specifications, incorporating wood into a building's design is one of the easiest ways to reduce a project's environmental impact and cost (e.g., through pre-fabricated wood sections that can be easily installed on-site to reduce construction time). Why? Because wood is the only building material that stores atmospheric carbon." Here are some facts that illustrate his point:
- The carbon that is absorbed by trees in their lifetime remains "imprisoned" in the wood;
- On average, a single tree is capable of "locking" up to a whole ton of carbon during its lifetime;
- When trees die and the wood rots, the absorbed carbon will return to the air, contributing to CO2 buildup in the atmosphere.
By harvesting trees before they die of old age, the carbon remains locked up and is prevented from returning to the atmosphere. Hence, incorporating wood in a design can easily lower the carbon footprint of any project, be it for structural or decorative purposes. Wood also requires a lot less energy for processing compared to other building materials. For example, trees require 1.5 mJ/kg of energy to turn into wooden building materials compared to 435 mJ/kg of energy needed to transform bauxite to aluminum.
Life Cycle Assessment (LCA) research by renowned entities such as the UN's Food and Agriculture Organization (FAO) in 2002, the UK Building Research Establishment in 2002 and the U.S. Consortium for Research on Renewable Materials in 2004 have all shown wood's cradle-to-grave ecological quotient to be superior to that of steel, concrete and plastics. In 2012, the American Hardwood Export Council (AHEC) published a report of the first stage of its LCA of rough-sawn kiln-dried American hardwood lumber. The report contains data on the environmental profile of U.S. rough-sawn, kiln-dried hardwood lumber using a comprehensive set of environmental impacts, from point of harvest in the U.S. through to delivery at the importers yard in major export markets. It provides quantitative data on Global Warming Potential, Acidification Potential, Eutrophication Potential, Photochemical Ozone Creation Potential and Ozone Depletion Potential. If similar LCA's were conducted on other building materials to examine their environmental impact, wood would come out tops and win hands-down in each of these categories.
| MATERIAL | ENERGY REQUIRED FOR CONVERSION OF RAW MATERIAL INTO USABLE BUILDING FORM (MJ/KG) |
|---|---|
| Bauxite → Aluminum | 435 |
| Iron Ore → Steel | 35 |
| Trees → Wooden Building Materials | 1.5 |
Frequently asked questions
What is the world's oldest wooden building and how old is it?+
The Horyuji Temple in Nara, Japan is officially the world's oldest wooden building. Dendrochronological studies show its wood came from trees felled in AD 594.
Why is wood considered a carbon-neutral building material?+
Wood is the only building material that stores atmospheric carbon. The carbon absorbed by trees during their lifetime remains imprisoned in the wood, and harvesting trees before they die of old age keeps that carbon locked up instead of returning it to the atmosphere.
How much carbon can a single tree store in its lifetime?+
On average, a single tree is capable of locking up to a whole ton of carbon during its lifetime.
How much energy does it take to turn trees into wooden building materials compared to other materials?+
Trees require only 1.5 mJ/kg of energy to be converted into wooden building materials, compared to 35 mJ/kg for iron ore to steel and 435 mJ/kg for bauxite to aluminum.
What does the 2012 AHEC Life Cycle Assessment report cover?+
The American Hardwood Export Council's 2012 LCA report covers the environmental profile of U.S. rough-sawn, kiln-dried hardwood lumber from harvest through delivery at importers' yards in major export markets. It provides quantitative data on Global Warming Potential, Acidification Potential, Eutrophication Potential, Photochemical Ozone Creation Potential and Ozone Depletion Potential.
What is an example of a long-lasting wooden building in Malaysia?+
The Seri Menanti wooden palace in the state of Negeri Sembilan has stood steady for 105 years and counting, demonstrating wood's durability when properly applied and maintained.