What To Know When Building A Strawbale Home
In 2009, I was the local organizer for the GreenBuilt Tour of the New Mexico Chapter of the US Green Building Council. There were 14 homes on that tour – passivhaus, off-grid, passive solar and one of recycled materials.
My favorite homes, though, were the strawbales built by Thomas Soule and Charlie McGarrity of Natural Builders, LLC. I have never felt so good in a building as I did in those strawbale homes, shops and studios! I couldn’t help but write about them!
What makes strawbale construction so eco-friendly?
- Recycling! Strawbales are agricultural waste, the stalks of grains that have been harvested. Instead of being burned in the field, they are bundled up and turned into homes.
- Low carbon footprint. Because they are made of recycled material, they have low embodied energy. Very little energy was used to create them, so they have a low environmental impact.
- Renewable. The grains used in strawbales are annual plants, grown every year, making this a truly renewable building material.
- Local buying. In most cases, strawbales can be purchased locally, reducing transportation costs and the burning of fossil fuels.
- High insulating properties. There is no standard R-value of a strawbale wall. It varies depending on the grain and how densely it is packed into the bale. Thomas said that he finds his walls are about R30, which is very high, especially for a wall.
- Excellent indoor air quality. A strawbale home with a natural plaster coat will breathe, allowing an air exchange between indoors and out, always recycling stale air with fresh. This does not create drafts, but instead keeps the air moving and fresh.
- Durable. Strawbales have been known to withstand earthquakes and hurricanes. Homes built in the mid-west during the westward migration of the mid-1800s are still standing and in excellent shape, too. They are also resistant to bugs and fire, despite common beliefs of the opposite.
- Affordable. Strawbale construction lends itself well to owner building, which saves the expense of a contractor. If you do hire a contractor, though, the cost is comparable to a traditionally built home.
What Are Strawbale Homes Like On the Inside?
What is it about strawbale that is so yummy once you’re inside? The first thing you notice in a strawbale home is the sound level, or lack of one. The walls absorb sound, so there are not echoes, no tinny sounds, no noise from another room. The acoustics make it very comfortable to be inside. Exterior noise is blocked as well. This very quality also makes a strawbale home cozy. When you are inside, you feel wrapped up and cuddled, no matter how large the space is. Earthen plaster adds to the sense of coziness. You can’t beat the warmth of natural building materials.
You also notice the fresh air. As stated above, the materials are permeable, allow a slight air exchange between indoors and out. I have never felt stuffy in a strawbale, even though they are built very tight. The designs and details are unique. The width of the strawbales allow for deep window sills, window seats and built-in cabinets and closets. The natural shape of the bales also lends itself to curves and softness, instead of the hard edge of a frame wall.
Things To Take Into Consideration When Building with Strawbales.
As with all building, check your local codes. Some localities may not even allow strawbale construction. In some states, a strawbale wall is not allowed to be a bearing wall. A post and beam frame is built, and the bales are infill. A second story can be constructed with the frame carrying the load.
The plans may also require an engineer’s stamp on them. This is not a huge expense ($500-1000), but it must be done. Make sure you can get financing. Lenders are very leery these days, especially with alternative building methods. If you are an owner/builder, you may be able to pay as you go. Then you are mortgage free, which is a bonus!
Find a reputable supplier. Bales should be golden in color to indicate that they have been kept dry. You won’t have problems if your bales have a low moisture content. They should also be densely packed. A bale should not change shape when picked up. Study, and ask a lot of questions. Hire an experienced contractor, if you are going that route. If you are building yourself, understand the process completely so you can work with others. Take a workshop or work with someone on a project. Learn as much as possible!
As always, get all your necessary permissions and inspections. Don’t cut corners. When you are done, enjoy your new, energy efficient, cozy, beautiful, acoustically perfect and unique home!