If ‘the clothes make the man’ so too do ’the materials make the building’. That may seem like an obvious statement… Of course the materials make the building! What I mean is, not only is the building made of the materials but the materials can make the building more efficient, more cost-effective, easier to construct and reduce its impact on the environment. In a previous post I stressed the importance of the Building Envelope in energy conservation in all buildings. The practice of sustainability takes material selection at least 2 or 3 steps further though in ways you may not have considered. In general the selection of sustainable building materials will either conserve resources, preserve the environment by reducing energy consumption or carbon emissions, improve indoor air quality or some combination of the three.
Possibly the most talked about focus in the selection of sustainable materials is using materials that are either rapidly renewable, salvaged or recycled to some extent. Recycled materials of course are materials that, after initial use, are then collected and used again to make building products. Rubber tires may become part of a gymnasium flooring product or playground equipment for example.
Salvaged materials are materials that have been previously used and reclaimed for use in new construction without further manufacturing. An example might be bricks from a demolished building being reused in a new building.
The term Rapidly renewable refers to a material that can be quickly replaced once harvested like bamboo. The use of bamboo has become common in sustainable buildings because of how quickly it grows (some species grow multiple feet in one day), unlike hardwood trees which take many years to grow. Cork is another example of a sustainable building material. When Cork is harvested, the tree isn’t destroyed, the bark is stripped off the tree and the tree left to regenerate.
Energy use and carbon emissions to acquire the materials, ship and manufacture a product are important considerations in selecting sustainable materials. An emphasis is placed on locally available materials that are available closer to the construction site. Using a material manufactured in the vicinity of the construction site isn’t always possible, but when it is possible the material should be considered favorably.
Material selection can also effect indoor air quality. Selection of low-emitting materials (materials that emit unpleasant or irritating smells that may be harmful to the buildings occupants such as formaldehyde) can greatly increase indoor air quality. Carpet, cabinetry and paints are common areas where selection of low-emitting materials can have a huge effect on air quality.
Careful consideration of these items will greatly improve a building’s performance.