Straw Bale House

Sustainable Tiny Housing

Straw Bale Homes

A surprising option for sustainable living could be building our home using straw bale. Building and choosing a sustainable living is gaining popular but during construction there is a huge amount of waste be it cobb or waddle. Straw Bale can provide a way to minimize the waste while construction.

What is a Straw Bale home?

There are mainly two types of straw bale homes. One is a load bearing straw bale home, and the other is of a post and beam structure. For the former one, there is no structural framing in the walls other than around the windows and doors to hold them in place on the roof attached directly to a box beam which is made of wood at the top of the wall. The whole assembly bears down on the bales and those act as the wall strength. Latter one is an actual framing system in the walls which is used for insulation and backing. The choice you are going to make what straw-bale construction method to use depends on your budget, availability of materials and physical help you have access to.

Load Bearing

With a post and beam structure, anything could be done with the design. If you are looking at building with more variations and unique features, then post and beam structure would be your choice.

Non-Load Bearing

Load Bearing works well for smaller structures but if we want to have more options at our hands we shall go for post and beam structure. In this way we can even build multiple stories, different wall angles.

Why Straw Bale?

Straw Bale home not only reduces the waste but also provides a well isolated house.

Walls made from straw bales are strong and very efficient. Straw bale houses are eco-friendly and cost-effective. They require less energy to heat and cool. The walls are strong and can last for more than 50 years. Straw bale design is unique and one-of-a-kind.

Natural, breathable

These houses are made in a way that it might breathe. Science might disagree but the walls allow dry air to move very slowly. In a simple way the walls are not going to have moisture. It would stay dry.

Easy Maintenance

They are easy to maintain and can be easily built with the most basic of tools. Building a straw bale house is a fun experience.

Straw bale houses are a source of pride for the families who live in them. The children who run in and out of their homes feel a sense of belonging. The adults who live in them know they are doing something good for the planet.

To build a small (700 sq ft), energy-efficient straw bale house, you might need to spend between $35,000 and $40,000.

The first time you lift a bale into place you know you are doing something special. When you get your first glimpse of a straw bale house standing tall you know something wonderful is happening.

Brittany Gerallys
Digital Nomad

What kind of plaster to use?

Lime Plaster

Lime is lot more versatile and when you are building with Lime you can be more creative and go beyond the restrictions of clay plaster.

You can purchase lime online/local home building supply store in small bags/buckets or in bulk it’s usually a mature pre-mixed substance containing fat lime, lime putty, sharp sand and various fibers including hemp..

Clay Plaster

The traditional clay-based plasters are not as strong as lime-based plasters.

Lime plaster or clay plaster or any other natural plaster are considered moisture loving materials. Lime and Clay plasters are microscopic they draw the moisture away keeping the walls dry.

Lime is lot more versatile and when you are building with Lime you can be more creative and go beyond the restrictions of clay plaster. The traditional clay-based plasters are not as strong as lime-based plasters. Lime plasters are much stronger binder that is significantly less prone to cracking and mildewing.

There are different kinds of limes that you can work with. For example, Hydraulic lime is the strongest of all limes. It is obtained by hydrating lime, and it will not get hardened unless it has access to air. This is a very strong and durable lime that can be used in thick walls.

On the other hand, limes obtained from not carbonated rock lime when they have access to air, they may fail to produce a nice and strong plaster. Lime plaster provides sheer strength structurally. It can be used both in interiors & exteriors. People also use unearthed plaster on the exterior side of the wall, but keep in mind that it is much harder to maintain, and it is better to used them the insides.

Unearthed Lime Plasters are durable, water-resistant, and naturally suitable for humid conditions without the use of chemical fungicides. They can be tinted with natural earth and mineral pigments and can be further customized by adding vermiculite, and muscovite glimmer. 

The plaster on the insides should be made thicker to slow down the buildup of moisture.  You can also get your plaster when you are digging for the foundation of your home. The mud plaster is free, but it would not be long lasting like the lime plasters or the plaster that you can purchase from the store, also mud plaster needs more maintenance.

What about the fire risk?

Most people are concerned with the risk of catching fire in straw bale homes, it’s understandable concern.  An independent testing known as ASTM 2-hour fire and hose stream test was performed. The cement/lime plastered wall easily passed the test.

The test that was conducted proves that straw bale homes are three times more fire resistant than the conventional homes.

Leaking?

Straw Bales are like sponge, so it is possible for any leaking to occur. A few precautionary steps are taken to damage control in case of plumbing leaks.  If there is a huge rainfall, the plaster will interact with exterior climate and draw back the moisture leaving the air dry. Natural plasters to a really good job of, of helping that system be effective.

Cost?

Thinking about building a house we need to think about the budget. When building a house with straw bale first though that might strike is the cost compared to conventional sustainable homes such as a sand home. Cost depends on the architecture and the styles. Looking at two homes one a straw bale home and another a conventional home the former shall take 10-12% more cost to build. If we judge the efficiency straw bale homes will prove 10-15% cheaper in the long run.

Workshops?

I found few straw bale home building workshops online and found that they are geared towards teaching the about the process of building a straw bale home. I am looking for people who attended a workshop and are going on to build a house. Assuming that many of the course participants went to the workshop have a goal to build their home out of straw.