There are several advantages to building with straw bales:
- Exceptional R-value (approximately R30-40)
- Large reduction in heating costs (US DOE found a 60% reduction, CMHC 25-75%)
- Reduced thermal bridging (this occurs in traditional stud framed homes)
- Reduced amount of lumber used thereby preserving forests
- Reduced carbon footprint (carbon stored in straw is normally released by burning or decomposing)
- Provides great sound proofing (strawboard is commonly used in recording studios)
- Qualifies for various green building rating system points (e.g. LEED, etc.)
- Extremely low embodied energy (energy used to create product from raw material)
- When plastered it becomes a good thermal mass
- Vapour permeable (no need for plastic vapour barrier)
- Inexpensive
- Found locally
- Straw is an agricultural bi-product
- Provides new, additional farm income
Furthermore, there are advantages to building with an OTWS prefabricated system:
- Fast Assembly -Walls are built off-site while the foundation is being built. Wall assembly normally takes days as opposed to weeks, significantly speeding up the time for construction.
- Controlled Environment - Harsh climatic conditions are avoided. Construction can occur 365 days a year. Controlled curing of cement allows for a stronger more durable plaster.
- Easier Plastering - The walls are built laying flat on the ground. By plastering horizontally (with gravity) as opposed to vertically (against it), it becomes much easier and faster. The overall finish is much smoother and flatter than plastering on site.
- Lower Labour Costs - Walls can be produced much quicker and more effectively than the traditional way of stacking and plastering bales on site
- Consistency - Since the walls are built in a factory, each one is quality controlled before it leaves the factory. Each wall unit is assured to meet the specifications before it is shipped off.
