The green building movement isn’t exactly new, with first contemporary experiments starting in the 1970s as a response to the energy crisis and increasing oil prices. But most initial efforts fell to the side when energy costs dropped and stabilized. The sustainable homebuilding movement has taken off again in more recent years largely due to increasing concern over the declining state of the environment and desire to cut energy costs.
In early 2020, the National Association of Realtors (NARS) surveyed residential agents and brokers and found 61% of survey respondents said homebuyers were very or somewhat interested in sustainability.
Additionally, several research studies show that homes with green certifications including LEED (Leadership in Energy and Environmental Design), ENERGY STAR, National Green Building Standard, and the Home Energy Rating System (HERS) Index, sell for more than non-certified homes. The average increase in resale value of a sustainable home is 9.5%, a benefit to homebuyers and selling point for builders.
Using sustainable materials can also save builders money during construction. Though the initial cost of materials may be higher, like triple-pane windows, the overall costs of a build can actually decrease. And using recycled materials can actually mean a lower upfront cost and quicker construction period, which reduces labor costs.
With the desire for eco-friendly living, it’s important for housing professionals to know what options exist for sustainable building materials to make educated choices on what they should consider investing in.
Top sustainable materials for homebuilding in 2021
Here is a list of some sustainable building material trends shaping the future of green homebuilding today:
Bamboo is technically a grass and has a very small impact on the surrounding environment when cut down – quickly regenerating from its root, unlike wood. Bamboo is also sustainably sourced, harvested by hand instead of a machine, which eliminates harmful gas emissions. Eco-friendliness aside, bamboo is light-weight, but more durable than hardwood so it lasts longer. It’s a great alternative to heavy building materials and can even be used to replace concrete. Bamboo is being used more to replace hardwood flooring, which offers a more durable, timeless look that many homebuyers want.
Timbercrete and Ferrock
Timbercrete is a mixture of recycled concrete and sawdust. It is lighter than concrete and can be used for paneling and cladding. Ferrock is a similar material, combining recycled materials like steel dust to create a concrete-like substance. Ferrock is stronger than concrete and traps carbon dioxide as it dries, which is beneficial because traditional concrete production contributes to roughly 8% of CO2 emissions each year.
Recycled plastic concrete
Speaking of concrete, it can be made from recycled plastic as well. This uses waste that would otherwise sit in landfills and emit greenhouse gas. Recycled plastic concrete creates a durable, light-weight and more flexible option that is cheaper than traditional concrete mixes. It offers: lower carbon emissions, fire resistance, durability, enhanced thermal and sound insulation, chemical and solvent resistance, and the ability to withstand extreme temperatures and pressure.
Straw can be used to build walls, replacing concrete, wood, fiberglass, plaster, stone, and gypsum. Strawbale is naturally fire-retardant, resistant to moisture, has great insulating properties, and is easy to harvest. Many Australian buildings are constructed with strawbale walls and cement or earth for rendering.
Cork is made from the bark of the cork oak tree and is both fire and water-resistant, meaning it cannot rot like wood. Cork is a great alternative for insulation, shock absorption, and flooring. In fact, NASA uses cork for insulation in rocket parts because of its thermal properties.
Most homes aren’t built with much metal, but using recycled metals where needed can help reduce the amount of energy used in the traditional mining and manufacturing of aluminum and steel. Steel, for example, requires 75% less energy every time it’s repurposed. Metals keep their properties, so they can be recycled multiple times and are usually stronger, more water-resistant, and last longer than freshly manufactured metal.
Structural insulated panels (SIP)
SIPs are created by placing foam between pieces of plywood, cement, and strand board. They can be used to form walls, ceilings, or floors, in replace of traditional wood frames. These panels are stronger than wood and help homebuyers conserve about 50% more energy because they create a higher level of air tightness. Less draft means reduced heating needs and energy savings.
Engineered wood, also known as cross-laminated timber (CLT), consists of different types of wood meshed together. This type of wood has incredible strength and stability, great thermal and insulation properties, and reduces building-site waste because it’s prefabricated. In fact, in 2018, Australia built a 9-story building in Brisbane with floors and walls constructed completely of cross-laminated timber.
It’s important to note that some engineered wood could release chemicals and harmful solvents into the air so it’s critical to ask your building product manufacturer what approach they use to create these prefabricated panels.
Similar to recycled metal, recycled wood requires significantly less energy to produce. It can be used for anything fresh wood is used for; Walls, floors, cabinets, decks, beams, you name it. What’s great about reclaimed wood is that it’s cheaper to buy and usually comes from older trees. Old-growth trees are resistant to rot and termites, stronger, and more durable, as opposed to new-growth trees that come from forests and tree farms, grown solely to be sold for timber.
Looking to the future
Sustainable homebuilding isn’t going anywhere, so keeping up with environmentally-friendly materials and techniques will be critical for homebuilders who want to stay relevant and have a more positive impact on the environment.