The visible and devastating effects of climate change have many consumers trying to reduce their carbon footprint and make more conscious shopping decisions. In some cases, it's small efforts like buying metal straws in place of plastic ones, and in other cases consumers are making big changes like opting for an electric car -- or foregoing one altogether.
Homeowners who are building or remodeling can choose more sustainable options for building materials. By using organic products, reclaimed materials and local resources, you can reduce the energy expended and waste created while building, improving and living in your home.
Here are sustainable building materials to consider for your home:
-- Earth shelter.
-- Reclaimed wood.
-- Reclaimed metal.
-- Precast concrete.
-- Shipping container.
-- Rammed-earth tires.
-- Recycled steel.
-- Sheep's wool.
-- Plant-based polyurethane rigid foam.
-- Straw bale.
-- Recycled plastic.
An earth shelter home is primarily covered by a hill, which either already existed or was built from flat land to cover the structure. You'll want to use a home builder who has experience with earth shelters to avoid water leakage issues or structural instability. For these structures, the reported benefits lie in the added protection from the elements and reduced utility costs since temperatures in the home stay relatively temperate.
Rather than buying newly cut wood from a lumber yard or home improvement store, give used wood new life. Reclaimed wood can be used for flooring, fencing, doors and window frames, as well as for furnishings like tables and chairs.
The Architectural Salvage Warehouse of Detroit makes finding reclaimed housing materials possible on a large scale, as the company disassembles buildings rather than demolishing them with a wrecking ball. By doing so, flooring, doors, cabinets and other materials can be purchased and reused for new building projects.
Just like with wood, metal materials can be reclaimed from a house that's set for demolition. Plumbing or electrical wiring that hasn't sustained damage or excessive wear and tear over the years can be used again.
When a sturdier material is necessary to create the outer walls of a building, concrete is often still a preferred option. But to reduce the energy required to produce it, prefabrication is becoming more common. This means the slab is created in a factory setting and shipped to the construction site instead of being poured on site.
Prefabrication of this type is more likely to be seen in construction for large-scale public construction like sewers, roads or bridges, commercial buildings, hotels and potentially large-scale apartment buildings.
Trees such as pine, oak and maple take years and even decades to grow back to the point that they can be harvested again for wood. But bamboo, which is stronger and more flexible, grows much faster -- in fact, it's the fastest-growing plant in the world, according to the Guinness Book of World Records.
"The limitation right now is the bamboo stock is not domestically located. Most of it is in China, Malaysia and places like that," says Gilbert Galindo, creator of Bamboo Grove, a website dedicated to informing the public about the benefits of bamboo. Galindo says he continues to see growing interest in bamboo farming and usage in the U.S., and expects it to become a key material in construction in the future. It's most often seen today as a flooring option.
Cork is another tree product that is physically flexible, strong and resilient. Resistant to moisture and known for absorbing noise well, cork is a solid option for flooring or even as a subfloor in place of plywood.
Like bamboo, cork mainly grows outside the U.S., primarily along the Mediterranean Sea. This makes the material largely cost-prohibitive compared with more common materials in the U.S., and it requires more energy to ship. However, the farming of cork oaks may increase as homeowners and builders pursue different material options.
When it comes to building material options, you can't get much more natural than mycelium, which is the vegetative part of a fungus. Mycelium bricks are made by combining the fungi with organic waste, and they are resistant to water, mold and fire, which makes them an ideal material for building construction. But mycelium doesn't just show potential in the construction industry: Scientific American reported in July on the potential uses for mycelium in food production and the advancement of medical technologies.
If your interests lie in recycled materials and you appreciate a more modern design aesthetic, a shipping container home may be for you. While a 40-by-8-foot container may provide the perfect exoskeleton for your new tiny home, be sure you research all the costs first. A shipping container has no natural insulation, so it can get very cold or hot depending on the outside temperature. Along with adding insulation, you'll need to cut window and door spaces into the outer structure.
Cob, a clay soil mixture with sand and straw, has been used for centuries in Europe as a building material. The mixture doesn't require framing and can simply be packed together and molded, drying from the heat of the sun. Because they're made by hand, cob cottages are often small and created by the owner, though two-story structures with fully operational windows also exist.
Made of a similar mixture to cob, adobe takes on a more structured, brick-like shape. While adobe and cob may both require additional insulation in colder climates, the materials' thermal qualities provide some heat. In a desert setting, adobe walls will absorb the exterior heat during the day, and then release it inside at night when outside temperatures have cooled. A historically popular building material in the dry climate of the Southwest United States, adobe is still used by skilled craftsmen in the region today.
Rammed Earth Tires
The combination of recycled and natural materials found on site can be enticing, and rammed earth tires fit that mold. However, the process of packing dirt into individual tires to build the exterior walls for an entire home requires a lot of motivation and physical labor. For someone set on the style, it's extremely inexpensive to make, often with dirt near the home being used to pack the used tires, which can be purchased used from a tire shop, tire recycling site or even found discarded on the side of the road.
Earthbag construction uses a similar earth mixture to what is found in rammed earth tires, but the result is more brick-like. The earth mixture is placed in bags, which are often made of a plastic that can withstand the weight and exposure to elements. To provide better protection from cold weather or the heat in summer, incorporating insulation of some sort is needed.
Melting scrap steel to create new products is a fundamental part of steelmaking in the U.S. It allows for steel products to be used again and again, whether that includes old cars or the structural beams from demolished buildings. According to the Steel Recycling Institute, roughly 60 to 80 million tons of steel scrap are recycled each year into new steel products in North America.
To better use all products from the steelmaking process, Ferrock uses recycled materials including steel dust to create a concrete-like building material. But with steel as a key component, Ferrock proves even stronger that concrete. The material also absorbs more carbon dioxide than it creates. It remains in the early stages of development under IronKast, the company that holds the patent for the material.
In the growing list of concrete alternatives, wood is also incorporated by using sawdust or wood chips in a concrete or cement mixture, ultimately creating a lighter final product than traditional concrete blocks or slabs. The lighter weight cuts down on transportation costs, and the material uses parts of wood that would otherwise go to waste. Timbercrete is a trademarked brand based in Australia, while Faswall is based in the U.S. The two companies have different processes for creating their wood-and-cement building materials that offer a variation of perceived environmental benefits.
Unlike many of the above building materials, grasscrete does not form blocks or panels for building, but serves to reduce the amount of concrete required in a walkway or driveway. Where paving would otherwise be, a cutout pattern makes it so grass grows consistently while still maintaining a hard surface. Grasscrete increases the area's ability to absorb water compared to a space paved over completely, and it also allows a greater area for plant life to grow on the property.
Using a combination of paper with other materials to create a concrete-like material, papercrete allows builders to make something entirely new from recycled materials. A simple Google search can yield do-it-yourself guides for creating your own papercrete, which is easier to make due to the easily accessible ingredients. It can be used as a plaster or formed into bricks. However, it isn't the most durable material, and it is more likely to wear away when exposed to the elements or a moist environment.
Like timbercrete, hempcrete is a lighter weight than traditional concrete, which cuts down on shipping costs. Hemp farming has largely been kept at a minimum in the past due to marijuana laws that make hemp, which is a strain of the cannabis plant. However, at the close of 2018 the U.S. legislature made hemp an ordinary agricultural product, thus making it legal to grow. Individual states have overturned laws that outlaw hemp farming as well, which means hempcrete may become a more common building material in the future.
Just like a wool sweater will keep you warm in the winter, wool can be used as insulation for your home. The fact that it grows naturally on sheep makes the energy required to produce wool fairly minimal. A big house will require a lot of wool to insulate the whole thing, however, so you may need to buy wool from a few flocks or even buy it over a few seasons.
Plant-Based Polyurethane Rigid Foam
Another insulation option is to look for plant-based polyurethane foam, rather than the commonly used plastic rigid foam. The insulation made from kelp, hemp and bamboo effectively keeps out moisture and heat or cold. The use of this plant-based rigid foam came about when Malama Composites Inc., based in San Diego, sought a better alternative to dangerous materials being used in surfboards, and has since expanded to insulation, packaging and other uses.
Straw bale is rising in popularity as a natural building material, and it's also known as a good insulator. You just need plaster or a similar material to protect the bales from the elements, making a bale houses fairly affordable to build. The straw bale works as an effective insulator and can be used as such even with other building materials for the outer or inner structure of the house.
Research continues on how to recycle plastic into a useful building material to cut down on the amount of plastic waste in the world. Recycled plastic lumber, which is essentially a recycled plastic product with the capabilities of wood, is developing as a viable construction option. To ensure the process of recycling the plastic and its use as lumber is beneficial to both the environment and the public, the American Society for Testing Materials has developed standards for the creation and use of recycled plastic lumber.
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