Some building materials might be considered “sustainable” by some definitions and under some conditions. For example, wood might be thought of as sustainable of it is grown using sustainable forest management, processed using sustainable energy delivered by sustainable transport, etc. Under different conditions, however, it might not be considered as sustainable. College of Architecture and Urban Planning, the University of Michigan, United States, has identified the characteristics of sustainable building materials considering its life cycle as below:
- Controlling and preventing pollution in material manufacturing processes;
- Reducing waste generation in material manufacturing processes;
- Containing recycled content;
- Embodying energy reduction in material manufacturing processes;
- Using natural resources such as wood, soil etc.;
- Designing to reduce waste generation during construction or installation;
- Using local materials;
- Promoting energy efficiency in buildings;
- Helping with water treatment and conservation;
- Using non-toxic or less-toxic materials;
- Promoting renewable energy system;
- Having longer life time;
- Reusability of the materials;
- Recyclability of the materials;
- Biodegradability of the materials.
These characteristics can be used to make a set of criteria for identifying sustainable materials as shown in Table 1
Table 1: Criteria for identifying sustainable materials (Jong-Jin et al., 1998)
|Manufacturing process||Building operations||End-of-life management|
|– Waste reduction– Pollution prevention
– Recycled content
– Energy reduction
– Natural materials
|– Energy efficiency– Water treatment and conservation
– Renewable energy source
– Long life span
|– Biodegradable– Recyclable
Sustainable materials used in household or building can be categorized into constriction materials, furniture and appliances. Examples of those sustainable materials are presented in the next paragraph.
- Concrete is considered as an excellent choice of construction material for creating thermal mass in a passive solar designed building. Thermal mass helps controlling a temperature of a building and keep it warm in winter and cool in summer. Concrete can have a long life time if it is designed and used properly, can be formed into shapes and designs. Concrete is recyclable and fire resistant (Green Cross Australia, 2010). Manufacturing of concrete creates a lot of impacts to the environment. New techniques have been applied in order to reduce impacts to the environment such as sourcing aggregates from local areas, reducing the use of cement in concrete manufacturing by using high performance cement, and using high performance concrete in the construction. Figure 1 shows example of companies who produce low-carbon concrete.
- TimberSources of timber should be considered carefully because timber obtained from natural forest in not a sustainable material. If possible, reclaimed or recycled timber from demolished buildings and structures are preferred. Timber from plantation is also acceptable if new timbers are needed (Green Cross Australia, 2010). For example, rubberwood from rubber plantation in Thailand are currently used as a material for wooden furniture production, which are sold in Thailand and abroad. Figure 7.XX shows examples of wooden furniture produced from recycled wood.
- Timber is one of popular materials for house construction and furniture production since it is a flexible and strong material. Timber is known for its strength to support the weight of a building and renewability. Most timber has little thermal mass. High density woods have moderate thermal mass but short thermal lag time; therefore, wooden buildings need a good insulation liner or additional insulation from concrete.