What are sustainable construction materials?
Material technology continues to advance, creating new and novel possibilities for the construction industry. Today, there is a growing variety of sustainable construction materials taking the place of traditional materials. Traditional sources of material range from lumber, brick and concrete to steel and glass, but that barely scratches the surface on all the materials utilized in a construction project.
Picking the right sustainable construction material for your project depends in large part on your location. For some, wood may not be so easy to source sustainably, so choosing other options such as concrete may be more cost efficient and sustainable.
Concrete and Cement
One of the most ubiquitous construction materials is concrete. It is typically made from limestone, marl, sand and clay which are then crushed and mixed and put into a kiln. This process transforms and hardens the material which is later mixed with gypsum and ground up to become cement. Some cement companies integrate sustainability into their practices by returning exhausted quarries to nature and using biofuel (fuel derived from biomass) to help run their processing facilities and kilns.
Alternatives to cement can be in the form of fly ash concrete. Fly ash is a byproduct of coal combustion which is typically thrown into landfills. This fly ash can be mixed with limestone and water as a filler to reduce the amount of quarried minerals going into the concrete. Because concrete itself comes from natural resources, it is important to choose a concrete brand that doesn’t over extract these raw mineral resources and instead finds ways to recycle components and operate in a more sustainable fashion.
Wood is also another common material used in most construction projects. Unfortunately, due to the constraints from Covid-19, a lack of operating processing plants has drastically increased the price of lumber. When grown sustainably and responsibly, using wood for construction does not put much strain on the environment. In fact, trees actually benefit the environment in their ability to sequester carbon. One should look for companies that practice responsible forest management and that are FSC certified (Forest Stewardship Council). Companies that use these certifications are committed to advancing the practice of sustainable logging and promoting forest productivity and regrowth after they harvest the wood. Other sustainable sources of lumber are salvaged lumber and reclaimed wood. These sources of lumber come from previous construction projects in which the wood quality still remains intact and is able to be repurposed for other projects.
A material not often considered when it comes to construction is plastic. Instead of relying on materials that require mining, extracting or a lot of processing, recycled plastic offers an excellent sustainable alternative for many construction projects. These plastics, some of which are made from recycled content, can take the form of lumber and be excellent options for projects such as decks or walkways. For example, the company Vycom specializes in creating HDPE plastics that can “replace wood, metal and other traditional materials in a variety of applications.” They are also ideal for outdoor projects such as pergolas and fencing. Unlike wood, plastics have the added advantage of not having to be heavily treated for rot.
One of the earliest forms of construction materials albeit uncommon in most modern cities today, straw bales and rammed earth offer cheap and naturally occurring alternatives for filling out frames to houses and other structures. If sealed properly, bales of straw offer good insulation for all types of climate. Compacted dirt that is tamped down in wooden or metal frames is another sustainable material that can be used to create sturdy and eco-friendly walls, floors and foundations. This practice has been used for thousands of years, but as the trend towards sustainability in the built environment continues to grow, it has great potential for future uses as well.
Steel and Other Metals
As far as metals go, steel is one of the most sustainable metals there is. This is because steel is the most recycled metal available and while it is energy intensive to create, it is able to last for decades and be repurposed for many different projects. Aluminum is also considered a sustainable metal as it is easy to recycle and in doing so, saves around 95% of the energy that it would cost to produce new aluminum. In general, when looking to incorporate metals in a project, it is best practice to use durable metals that have a long life cycle and capable of being recycled or repurposed.
How to find eco-friendly, sustainable construction materials?
Sourcing sustainable construction materials can be challenging if you don’t know what to look for or where. Researching local construction companies is always a good place to start. If there is a company that supplies eco-friendly materials in your area, then that drastically reduces transportation costs (and commute emissions) for your project and at the same time supports the local economy. Reusing old materials such as reclaimed wood is also a possibility when trying to build sustainably. Local home maintenance shops and even large companies such as Home Depot and Lowes offer reclaimed wood.
Another option would be to visit local demolition sites and contact the owner to see whether you can purchase or remove some of the wood from the site. Beyond just plain wood, many salvaged materials can also be a good option for some projects. Architectural salvage retailers exist throughout the entire United States. A good list of retailers can be found here.
Another more encompassing website that sells eco-friendly materials (albeit more suited for interiors such as flooring and paints) is Green Building Supply. The company RateItGreen is a green building directory that offers a wide variety of green building products and services to help construction companies and individuals access a wide variety of sustainable construction materials, techniques and how-to’s. Lastly, online platforms such as Craigslist and Facebook Marketplace are teeming with items of all kinds, often affordable or free.
Why use sustainable construction materials?
The environmental benefits to incorporating sustainable materials into your construction projects are numerous:
- Reduces landfill waste
- Conserves virgin resources
- Promotes healthier indoor air quality; sustainable materials limits the use of toxic materials such as asbestos for insulation or chemically treated wood.
- Supports the local communities when sourced locally
- Cheaper transportation costs if bought locally.
- In some cases, it offers a cheaper alternative (e.g. straw, recycled plastics, etc.)
Successful projects that used Eco-friendly building materials
UpCycle – Austin, Texas
This building was the site of an old warehouse and has now become a lively and attractive office space. 95% of the existing building infrastructure was reused including the original restored metal and all other usable material that was found on site during the renovation. This creativity and innovation in the renovation process prevented the emissions of over 1,500 metric tons of CO2.
S.I. Container Builds – U.S. and Canada
U.S. and Canada-based, S.I. Container Builds specializes in repurposed shipping container living spaces, offices and studios. Sustainable materials are incorporated in every build such as recycled Corten steel and reclaimed wood. Strict recycling practices are also followed during the construction process.
Holcim – Switzerland
This Swiss-based company is a global leader in building materials and has recently expanded their product line into more sustainable cement. The manufacturing of their “ECOPact” concrete produces 30% to 100% less carbon emissions than traditional concrete. Some of their “Green Cement” products include upcycled construction and demolition materials. Such upcoming innovation highlights the potential and economic viability of sustainable building materials.
Taipei Public Library – Taipei, Taiwan
Built from wood sourced from managed forests, the Taipei Public Library is heralded as one of the most sustainable buildings in all of Taiwan. The building consists of many large windows to utilize natural light, limiting the amount of energy needed for lighting the interior. The roof is covered by a layer of soil to improve insulation and is sloped to capture and conserve the rainfall for reuse in the building.
Bullit Center – Seattle, Washington
This six-story office building has been a shining example of sustainability in the construction process. In order to reduce the use of concrete, it is mainly limited to the bottom of the building for its load carrying capacity. For the building’s timber frame, project managers sourced 100% of their lumber from FSC certified sources. The structure is then reinforced by steel connectors to hold together the wooden beams and insure that the building remains intact for many decades to come.
Clearly, the variety of new and novel sustainable construction materials is growing and with them comes a significant benefit to the environment. Further, the marketability of these green materials can help make your construction project stand out. In pursuing sustainability certifications, such as LEED or WELL, it will also help to have used some of the materials highlighted here.
The construction industry is beginning to realize the potential that sustainable materials have as viable sources for construction. As this industry is one of the largest contributors to emissions, pollution and energy use, it is time for industry leaders in this space to become more eco-conscious and begin transitioning to greener building methods and materials.
About The Author
GBB Green Ambassador
Peter Louthan is a content writer for Green Business Bureau who is interested in how the private sector can generate value from sustainable business practice. Currently he is pursuing a Master’s Degree in Sustainable Energy and is eager to learn how emerging technologies in this field can help transition the world towards cleaner energy and lower the dependency on fossil fuels. Outside of academia, Peter enjoys hiking and the outdoors as well as watching soccer with his friends.