Choosing the right construction method is one of the most important decisions you’ll make when looking to build a home.
With the growing demand for eco-friendly and sustainable homes, straw bale construction has become increasingly popular.
However, before you take the leap, you’ll want to know the different straw bale construction types with their pros and cons.
There are different types of straw bale construction. Each type works well in specific situations to meet different needs.
The only way to know which type is right for your project is by understanding the pros and cons of the different approaches to straw bale construction before you get going.
In this article, I’ll discuss the types of straw bale construction and their pros and cons.
I’ll review each type, detailing their unique applications to help you identify what’s right for you. Let’s get started!
Straw Bale SIPs
Structural Insulated Panels (SIPs) are not new in the construction industry. These panels have become increasingly popular recently because they are cheaper and quicker to build with than insulated concrete forms (ICFs). SIPs can last more than 60 years.
Traditional SIPs are made from a foam insulation core sandwiched between two structural panels like an Oriented Strand Board (OSB). The main types of foam core used include:
- Expanded polystyrene (EPS)
- Extruded polystyrene (XPS)
- Polyurethane foam (PUR)
How do straw bale SIPs differ from their traditional counterparts?
Straw bale SIPs replace the foam core used in traditional SIPs with compacted straw bales. The bales are tightly packed within the OSB to form a strong, air-tight barrier.
- Excellent thermal insulation properties: Straw bale walls have R-values between R-17 and R-54. SIPs have a higher R-value because the bales are more tightly packed and don’t conduct heat well.
- Excellent soundproofing: Straw bale SIPs can block out a considerable amount of outside noise, making them a great choice for soundproofing your home. A study of two rooms revealed improved acoustic insulation from straw bales.
- They are sustainable and eco-friendly: Straw bales are made from a renewable resource. They also have little to no negative impact on the environment as they do not require energy or chemicals to manufacture.
- Fire resistant: These SIPs are tightly compacted to remove any air spaces that make it easy to catch fire.
- Unsuitable for roofing: Straw bale SIPs are heavy–an 8’x8′ panel can weigh about a ton. This makes them unsuitable for roofing.
- Time-consuming: Straw must be compacted to form a strong, airtight barrier. This is time-consuming and requires expert help.
- Expensive: These SIPs will cost you about $18 per square foot compared to traditional SIPs, which cost between $10 and $16 per square foot.
- More maintenance: Straw bale walls need regular inspection and maintenance because they can be susceptible to structural movements.
Ecococon Straw Bale Construction Types
Ecococon straw bale building is an innovative way of building that uses compressed straw bales as the main insulating material.
The approach incorporates panels of double-load bearing structure and straw bale insulation made with multi-directional press technology.
The double-load-bearing structure is made from wood. In most cases, straw bale makes up 89% of the composition, while wood accounts for about 10%.
These panels are prefabricated in a factory under controlled conditions. This allows for higher precision and uniformity of the panels.
The video below shows an example of an Ecococon house in Ireland:
- Lightweight: Ecococon straw bale homes are lighter than traditional building methods. This makes it easy to install and transport without using excessive energy.
- Highly insulated: These panels are more air-tight than other building materials, leading to better insulation performance. They have a higher R-value than conventional materials like brick or concrete.
- Fire-resistance: The panels are fire-resistant due to the tightly compressed straw bales that block oxygen from reaching any potential fuel sources.
- Easy installation: The panels are quick and easy to install as they come with pre-cut holes and grooves. This eliminates the need for laborious onsite construction work.
- Excellent acoustics: Ecococon can resist the passage of sound of up to 54 dB. This feature makes it suitable for people who want to block outside noise.
- Costly: Ecococon straw bale construction panels are prefabricated in a factory and undergo complex manufacturing processes that make them expensive.
- Limited design options: Since they are prefabricated, you can only use them in their delivered shape and size.
- Requires expert help: Most straw bale house builders are unfamiliar with Ecococon panels. Therefore, you may need to hire an expert, adding to the overall cost.
Do-it-yourself (DIY) is one of the cheapest ways to approach straw bale construction.
The process involves compacting straw bales with handmade tools such as baling wire, wire ties, and wooden stakes to form the thick walls of your house.
- Affordable: You don’t have to hire specialized straw bales experts or buy prefabricated panels. All you have to do is compact straw bales and start the construction process.
- It’s sustainable and eco-friendly: The straw bales used as the raw material for this type of building are agricultural by-products that don’t have adverse effects on the environment.
- High insulation value: When properly compacted, straw bales form an airtight barrier that helps to keep your home warm during winter and cool during summer.
- Time-consuming: DIY straw bale construction is more time-consuming than using prefabricated panels.
- Low-quality: If you’re a DIY beginner, there are high chances of not meeting all the requirements for a quality straw bale construction. The house might not meet straw bale construction codes.
Load-bearing straw bale buildings use straw bales as the primary structural building material to support the roof. Therefore, the walls support the load.
- You don’t need to fit the bales in a separate wooden frame
- It’s cheaper and faster
- You don’t need carpentry skills
- It’s the greener option
- Highly susceptible to bale slippage
- Highly susceptible to water damage
- Insufficient load-bearing strength
- The wall length is limited to 25 feet (7.62 meters)
Unlike load-bearing, non-load-bearing straw bale construction uses wooden post and beam construction to provide structural support to the roof.
- Non-load-bearing straw bale homes are stronger as the beams provide additional support
- Sufficient load-bearing strength
- You can build longer walls exceeding the 25-feet (7.62-meter) threshold
- Non-load bearing straw bale building is costly and requires carpentry skills to erect the beams.
- It might be less green because you need to coat the members of the wooden frame with preservatives to protect them against the elements.
- It’s a time-consuming building method because you must start by erecting the full frame and then slot the straw bale infill into it.
There are different approaches to designing straw bale buildings, each with pros and cons.
The options outlined above should give you a good starting point for further research and discussions with potential contractors to identify an approach that meets your requirements for a straw bale home.
If straw bale homes don’t appeal to you, try looking for an alternative form of sustainable architecture. We have made your work easier by creating an article with 10 of the most non-toxic sustainable building materials.