A House Made of Straw?

The more I delve into the why and how of natural building, the more important it becomes to make it a defining characteristic of any physical development by the Housing for Wellbeing initiative. So will it be a literal house of straw? Well, no...and yes.

I first came across the use of straw in building materials while reading about the LILAC (Low Impact Living Affordable Community) housing development in Leeds, England, where prefabricated panels of timber and straw-bale developed by the company ModCell were used in the development of low-rise buildings. Turns out straw-bale is a great insulating material, is fire-retardant, is strong enough for multi-storey structures, and unlike use of conventional construction materials that add to carbon dioxide and other greenhouse gas emissions, straw-bale and timber panels store and sequester carbon away, allowing for carbon-negative buildings. Straw is one option; builders also use hemp, clay and other low-waste, high-performance, renewable materials in natural building.

 LILAC eco-village

LILAC eco-village

 Prefabricated ModCell timber and straw bale panels  (Photos: http://www.modcell.co.uk)

Prefabricated ModCell timber and straw bale panels

(Photos: http://www.modcell.co.uk)

This can seem so far from accepted building practices that some will immediately relegate it to the realm of outlandish or unsafe. Others may be attracted to it but still view it as a fringe methodology. In reality, natural building is a field that has grown through dedicated research, testing, iterative improvements, knowledge drawn from generations of practice by indigenous cultures, common-sense, and of course, a care for the environment and quality of living for people.

Chris Magwood, a sustainable builder and teacher in Ontario, in his book Essential Sustainable Home Design, points out the folly in assuming that mainstream building practices are better than the alternatives:

“One of the first questions I am often asked when discussing new approaches to building is: ‘Does [insert name of material or system] really work?’ This is an entirely appropriate and important question to ask... The ‘new solution paradox’ is that we typically only ask it of new solutions, and completely fail to question existing, accepted solutions. There is an assumption that the ideas, materials, and systems we use commonly have somehow been ‘proven’ to work... In the realm of building materials and systems, however, development, testing, and establishment of industry standards have been far from rational and well-proven processes... most of our accepted solutions have not been developed with any coherent ecological principles or human health ideals in mind. We tend to expect new ideas or technologies to live up to unrealistically high standards, while at the same time normalizing existing ideas or technologies that are inherently, deeply flawed.”

GreenHome.jpg
cm-living_room.JPG.650x0_q70_crop-smart.jpg
 

Above: Canada's Greenest Home built by Chris Magwood and his team in Peterborough, Ontario, featuring prefabricated straw bale wall panels, earthen plasters, solar hot water, rainwater harvesting, natural finishes and much more. (Source: chrismagwood.ca, endeavourcentre.org)

 

Use of natural materials is one facet of green or sustainable building. There are, of course, other important considerations such as ecological impact to the building site, better water management, greening and habitat restoration, durability and easy repair of building components, etc. A passive solar strategy, where window orientation and size, shading, thermal mass and insulation are used together to passively keep a house cool in summer and heated by the sun in the winter, can also dramatically reduce its external energy demand. 

To get local and regional governments to update and improve their housing codes more quickly, the Resilient Design Institute is using the persuasive angle that it is becoming increasingly necessary for homes to be resilient to natural and manmade disasters. Climate change has already wreaked havoc on thousands of homes, made worse by poor human design and construction of the built environment, and economic shocks have similarly forced many people out of their homes. Green building strategies is one way to soften the effect of these disasters. Straw-bale and cob (a mix of clay, sand, straw and earth) structures, for example, are earthquake resistant and much more affordable than reinforced concrete. Passive solar use can drastically reduce reliance on the grid for heating and cooling, and rainwater harvesting can provide backup water supply. 

There is still a ways to go before natural and green building strategies become mainstream, especially in North America. Any ambitious project is likely to face a housing code battle with the local municipality, but more and more builders are taking on these battles and creating a steady shift towards awareness and embracing of practices that do better justice to our environment and ourselves.