The next straw: straw bale builds part of a greener future
Evolve Builders are a full-service general contractor offering green construction. They are Southwestern Ontario’s most experienced green builders and are pioneers of building ultra-modern, permit-ready, straw-bale houses. Within the last few years, Evolve Builders has been recognized as having taken the step into the future for their sustainable straw bale residential and commercial builds.
In retrospect, ‘their first institutional construction project was completed for Orangeville’s Island Lake Public School in the Upper Grand District School Board, which had issued a bid request for 2800-sq.-ft. stand alone school building that included two classrooms, seminar space and two single washrooms. This schoolhouse’s green features are transparent to students and teachers, but are used as educational tools. The building features a timber frame construction, exposed rafters, straw bale insulation, polished concrete floors and a grey water collection system to flush toilets. The insulation is so efficient that, at times, no supplementary heat is required in the winter.’ (Kenter, 2017)
After the completion of this first project, Evolve Builders was contacted by the school board a second time to replicate their first build, as well as adapt their green building technology, to create a relocatable portable. Today, the new relocatable portable is known as the Mobile Eco-Enclosures (mobEE). MobEE is an eco-friendly portable classroom that merges straw bale building material, and other natural building techniques with state-of-the-art construction technology. This building style was noticed internationally. Clients from around the world have approached Evolve Builders and have asked them for their designs and help. “Traditional portables are depreciating assets the moment they’re set into place,” says Polley. “We’re building permanent quality construction that happens to sit on a mobile chassis.”
Advantages of straw bale construction include, supporting the local farming economy. Furthermore, straw bale insulation has an increased insulation value when compared to other insulation materials for a home. Straw bale walls are thicker, thus increasing aesthetic value to a home. Straw bales have low-embodied energy, meaning that very little energy was utilized to manufacture the product. Even if straw bales are 100% biodegradable, homes built with this material have proven to last over 100 years, if properly maintained. Maintenance of a straw bale home is as easy as making sure the proper material is used during the build. As moisture is a straw bale homes greatest enemy. Areas where heavy rainfall is common, straw bale homes should be constructed by using lime-based plaster. Nevertheless, “it is typical for a home to drive moisture through the walls to the exterior during the cold winter months when interior heating both creates and moves moisture towards the cold exterior. As long as this moisture is allowed to escape to the outside, there will not be a problem. If, by the use of housewraps, the moisture is held in the walls, the damage can be extensive.” (Morrison, n.a)
During the process of retrofitting a straw bale home, the straw bales can be ploughed back into the earth, whereas fiberglass alternatives create a disposal problem. Finally, properly constructed walls made from straw bales are flame retardant when compared to a conventional wood-frame. Straw bale walls tend to be denser. They smoulder when an ignition source is removed.
As of May 2017, Evolve Builders have produced “six modules, complete with walls insulated with straw, floors and ceilings built with structural insulated panels, air source, heat pumps and thermoplastic polyolefin reflective roofing membranes.” (Kenter, 2017)
For more information on Evolve Builders visit their homepage: Evolve Builders Group
To read more about Evolve Builders schoolhouse build visit Daily Commercial News
- (2017, May 26). The next straw: builder takes straw bale construction to school. Retrieved from http://dailycommercialnews.com/en-US/Projects/News/2017/5/The-next-straw-builder-takes-straw-bale-construction-to-school-1024243W/?platform=hootsuite
- A (n.a). Straw Bale Construction and Water . Retrieved from https://www.strawbale.com/straw-bale-construction-and-water/