The choice of building materials is an important part of making a construction project sustainable and eco-friendly. This goal can be achieved through employing local building products or green building products, and it’s good to know some of the differences between the two.
Local materials are commonly defined as those that have been harvested or produced within the radius of 500 miles of the construction site. This, by itself, does not necessarily make them eco-friendly: imagine a wall panel that was made at a nearby factory that releases pollutants into the river that flows by. However, purchasing local materials has significant benefits in that their shipment reduces transportation costs, and they support local economies.
By contrast, the term “green building materials” refers strictly to products that have been made using sustainable practices, are non-toxic or biodegradable. It is important to keep in mind that many local building materials will also have these characteristics. Let’s take look at the most common categories of green building products.
One obvious example are inputs that are responsibly harvested from sources that are abundant or can renew themselves easily. These include bamboo for flooring, as this plant grows much faster than trees, cork (also for flooring), since it can be collected off trees without cutting them down, and straw for insulation. Sand and rocks for mortar are also in this category due to their abundance.
An interesting recent phenomenon is the creation of sustainable versions of materials that have historically been depleted, such as timber. Over the last few centuries, the area of forests has dramatically diminished, raising concerns about global climactic and ecological stability. However, there are now sustainable forests around the United States – most notably in Minnesota – that are managed in a way that ensures a steady replacement of felled trees with seedlings, thus preserving the balance and continuity of these ecosystems.
Another broad category of green building materials are recycled products. In this area, the sustainability trend has led to perhaps the greatest creativity among designers and manufacturers. For example, Curiosity.com reported on a house whose walls and carpets were made out of recycled plastic water bottles. While this may seem somewhat avant-garde, there are many more ways to use reclaimed materials. These include insulation made of recycled paper, or concrete that includes fly ash rather than Portland cement as an ingredient. Fly ash is a byproduct of coal burning, and given the amount of fossil fuel utilization in America, its use in construction is a great example of reclaiming what would otherwise end up on a landfill.
For those who would like to make their buildings both local and green, adobe is a great choice of material. It’s made from abundant resources such as clay, sand and water, mixed with organic materials like straw or manure, which are shaped into bricks and dried in the sun. The product can be used for walls, floors and other structures. The Green Home Building blog reports that soil that is composed of 20 to 30 percent clay is good for adobe, and that this type of soil can be found in many parts of the U.S.
Finally, substances with low volatile organic compounds (VOC) emissions can also be considered green building materials. These include organic paints and coatings, as well as cellulose for insulation.