Timber and concrete are some of the most common materials used in construction. However, those two materials are also harmful for the environment. Timber and wood product production is one of the 4 leading causes of deforestation, particularly tropical rainforest destruction, in the world. Making concrete produces about .93 pounds of carbon dioxide for every pound of concrete, or about 4 billion tons of carbon dioxide annually (which is approximately 8% percent of the world’s total annual greenhouse gas emissions).
Procurement and supplier intelligence company Beroe Inc. reports that sustainable building materials are the trend in the global construction industry, driven by the cost savings of using sustainable materials (up to 15%), compliance with laws, and incentives to increase sustainable practices like the increased demand for them in the market. These are the basic qualities that define sustainable building materials.
Qualities of sustainable building materials
Building materials can be considered sustainable if they meet some or all of the following qualifications:
- They are sourced locally. As businesses try to reduce their carbon footprint, they try to diminish the environmental impact of sourcing material, including shipping it. Sourcing material locally reduces the amount of CO2 released in transporting materials.
- They are (or may be) recyclable. Concrete, steel, plastic, wood, and bricks are all building materials that can be recycled. In fact, recycled steel has become a major component of sustainable construction projects. Reclaimed wood and brick have become desirable looks in many commercial and residential buildings.
- They are created in a sustainable way. Manufacturers that make materials in an environmentally friendly, low-waste way, compensating for their greenhouse gas emissions when possible and disposing of waste responsibly ensure that the production cycle of the material is more environmentally friendly, too.
- They’re made of recycled material. The construction industry is getting creative with recyclables: think tile made of recycled broken car windshields (used for backsplashes and bathroom tile), coal fly ash—leftover silica made from burned coal—made into concrete (ashcrete), building blocks made of compressed throwaway plastic, and even roofing tiles made of recycled disposable diapers.
Types of sustainable building materials
Considering the growth of the industry for sustainable materials, it would be impossible to provide an exhaustive list of all its innovations. Still, here are some of the major players in the sustainable construction movement:
The first documented use of hay bales in construction in the United States was a schoolhouse in Nebraska built in the 1890s that was eaten by cows about 10 years later. Once those resourceful farmers realized they could plaster their straw-bale structures, they hit on a great insulator and even framing material. Now straw bales are back: Made from agricultural waste and tightly packed and plastered, they’re strong and surprisingly fire-resistant. Contemporary home builders love straw bales for their soundproofing ability.
Homebuilders have focused in recent years on sustainable alternatives to chemical-filled insulation. While fiberglass and cellulose, both common insulation materials, are often made of recycled plastic reinforced by glass fibers or recycled paper fiber, the methods used to create them aren’t always environmentally friendly.
Enter sheep, whose wool can both increase the energy efficiency of a home and soundproof it. Wool also lasts longer than some natural insulators like cotton and straw. Plus, it’s naturally flame-resistant and non-toxic. Its downside: Wool often needs to be treated to resist fungi and insects.
Steel is both strong and pliable, allowing large commercial buildings to sway slightly to resist high winds. Historically, it hasn’t been used as frequently as wood to frame residential buildings, because of the lower cost of timber. But steel is 100% recyclable and is emerging as a hero in the green building industry. According to the American Iron and Steel Institute, an association of American steel producers, a 2,000-square-foot house requires about 50 trees to build, but a frame made from recycled steel comprises the equivalent of six scrapped cars. Steel doesn’t burn or warp, it’s water- and pest-resistant, and because it’s so durable, rarely needs to be replaced.
Giving old plastic and other trash new life is one way the construction industry is reducing greenhouse gas emissions and mitigating waste in landfills. Plastic from soda bottles and old nylon can be made into fiber for carpet production; reused plastic can be used to make roofs, cable pipes, fencing materials, and structural lumber.
Bamboo is one of the fastest-growing plants in the world, which makes it one of the most sustainable building materials because it regenerates itself. It is also endemic in every continent except Europe and Antarctica, making it a locally sourced product in many cases. While bamboo is a grass, it has a high strength-to-weight ratio and is long-lasting, so it’s a good option for flooring. Its downsides: Bamboo must be treated to resist insects and can swell and warp with exposure to moisture.