We all have heard or read about people all around the world trying to be as sustainable or “green” as possible, when building a home. I am going to go over some of the best materials that you can incorporate into building your new home. Keep in mind that even if the material is not natural, as in Adobe, Cob, Clay etc… it can still be considered “green”, based upon improved energy consumption and the impact on the environment it has to manufacture.
Straw-Bales
Now before you go imagining a home built with a bunch of hay, let’s take a look at a straw-bale closely to find out what about this building material is useful for home building and contributing to your sustainable home. There are only about two ways to efficiently incorporate straw-bales into your construction process, non-load bearing and load bearing. Straw-bales will need to have a dry density of 7 pounds per cubic foot and have a minimum thickness of 14 inches. Because straw is viewed as a readily available local material, it is one of the most popular natural building materials in use today.
Some Examples of Straw
- Wheat
- Rice
- Rye
- Barley
- Oat
- Other similar plants
The most realistic use for straw-bales is to incorporate them as in a non-load bearing way, or as insulation. A home constructed with this technique can lower your energy bills by up to 75%! Now, that is sustainable! Because of the thicker wall construction due to the size of the bales themselves, you will also cut down any unwanted outside noise. Against popular belief your house will not easily catch on fire, condensed packed straw will not catch fire due to the lack of oxygen. Keep in mind it is about 15% more in construction costs compared to traditional stick framing, unless you were to do the work yourself.
Earthbags
Building with earth is an ancient technique and has now evolved a little bit further. Earthbag construction is also known as Flexible-Form Rammed Earth (FFRE), it utilizes rammed earth with conjunction of bags and tubs as a flexible form. Recycled grain bags, misprints, burlap, polypropylene, or other economic choices are sustainable and cost efficient. The great thing about building with earth, you can use on-site soil or other local materials, greatly decreasing construction costs.
The main things you need to know about earthbag construction is that it works, it’s simple, efficient and beautiful. Because these structures can take an endless variety of shapes, the need for traditional building materials such as, wood or steel, is taken out of the process. This saves time, energy and precious natural resources. The homes are then covered with plaster and other forms of clay to assist in blocking out the sun’s rays; leading to efficient energy costs. So, the material; made from earth, contributes to energy efficiency, saves natural resources, clearly shows this “green” building material is a great choice!
Rammed Earth
Similar to earth bags, this building technique utilizes the same earthen materials without the need for bags or other types of forms. Currently, over half of the earth population calls a dwelling made out of earthen materials, their home.
The process of creating walls is done by ramming, or compacting earth into forms that create straight and sturdy walls. These walls are thick and wont contract or expand. Though, surface cracks may occur, it will not compromise the structural integrity of the home. These materials will not give you a large modern home, but you will make up for this in natural beauty, energy efficiency, and building costs. Rammed Earth will always be a leader in sustainable building and will continue to be a great choice for home builders.
Shipping/Cargo Containers
We talked about the different uses and project opportunities when building with shipping containers in our “Building with Shipping/Cargo Containers” post. It just happens that building with containers is also a very sustainable or “green” building material. The reason being, is the amount of steel that is reused every time a container is utilized in construction. Most would argue that recycling/ melting down the containers to cast new steel would be a great alternative to using the container as is. The problem is with recasting of steel; dust and other gaseous materials are released into the air. Not to mention the amount of energy and natural resources it takes to run the machines that assist in the recasting of steel.
The best and most realistic way of using shipping containers to construct your new home, would be designing a home that does not require a lot of fabrication or modification to the containers themselves. Cutting into the container for windows or doors will decrease the structural integrity of the container. Doing this will require more steel, and welding to maintain strength in the container, contradicting the main reason of recycling the containers in the first place. Creating a unique and modern home out of containers will most likely lead to much higher construction costs, but it is definitely possible. More simplified projects can utilize containers modified off site and then dropped into place at the project site, significantly lowering construction time. Containers are not built from the factory to be incorporated into home and other living environments so, you will face troubles with insulation and energy efficiency. Ultimately, shipping containers are not the most cost effective or most energy efficient option for home building materials but, if used correctly, you can construct a beautiful and simple home in very short amount of time. Not to mention the second chance you are giving to the container itself that may just have been rusting away in some field.
Insulated Concrete Forms (ICF)
Most builders and homeowners assume that “green” or sustainable engineering will automatically cost more than traditional home design, but this is not usually the case when it comes to using ICF. ICF are foam concrete forms that interlock and are filled with rebar and concrete. Utilizing ICF will allow for design flexibility when creating a long-lasting durable structure. Yes, it will cost slightly more originally but, the benefits over time that ICF will contribute to your home will far surpass the upfront costs. The number one reason behind these benefits is the superior insulation properties of this material. You will see significantly lower costs to heat or cool over the life of a structure utilizing ICF. The material does not decay and offers the structure extremely high degrees of wind, fire, insect and impact resistance. I know you are thinking, how can concrete and foam be considered a “green” building material? Well the answer is all within the energy efficiency that follows when building a structure with ICF. So, consider using ICF when building your home, it is one of the most realistic materials you can use when building a home out of sustainable materials.
Structurally Insulated Panels (SIP’s)
SIP’s are simple. They are generally made by sandwiching a core of ridged foam insulation between two structural skins of Oriented Strand Board (OSB). As an alternative to building a conventionally wood-framed home, SIP’s can be used for walls, floors, roofs, and room additions. The “green” factor of this certain material comes from the huge decrease in utility bills. SIP’s has an improved thermal performance that reduces energy consumption for less expensive heating and cooling systems. You will also save time and money in the construction process because SIP’s can used for framing, sheathing and insulation, all in one. They will be prefabricated in a factory with controlled conditions and can be custom designed for each home. Shipped right to the construction site ready for install will save time and the amount of labor required to construct a home by 1/3, compared to a standard frame home.
- SIP’s require significantly less dimensional lumber; up to 70% less.
- The OSB used come from fast growing farmed trees
- The efficient use of materials in the factory means less waste and reliance on landfills
It is obvious that SIP’s are a leader when it comes to sustainable building materials. Reduced construction costs, time and energy efficient, reduced negative environmental impact; it is a no-brainer to consider using SIP’s when you are selecting materials for construction of your new home.
Conclusion
Take your time when determining the options for designing and building your home out of sustainable materials. These are some of the most widely used, but there are many other sustainable options available. Make sure you research the best options for your environment, budget and design. If you are going to use a sustainable material to build your home be sure utilize its strengths and respect the weaknesses of your chosen material. Keep in mind that combining different sustainable practices into one structure could allow you to maximize your efficiency.