Natural building is about appropriate, sustainable construction, using locally available materials that are non-toxic and as minimally processed as possible. Earth building is a subset of Natural building where clay subsoil is the essential binding component in the wall, floor or plaster system. Historically, all buildings were constructed this way (using natural materials in the local vernacular) but things changed during the industrial revolution. Now day's in our post war, petro-chemical era, mass-produced, industrialised housing has largely displaced traditional materials and techniques. This has been at the expense of the environment, human health and the cost of construction has risen.
Industrialised building is heavily reliant on fossil fuels. In New Zealand, the construction, use and demolition of our buildings is responsible for 40% of our energy consumption, 40% of our waste generated and 35% of carbon dioxide (CO2) emissions produced (Burgess, Buckett & Page, 2013, p.12).
As well as being harmful to the environment, industrialised materials pose significant risks to people. "In 1984, a World Health Organisation report found that, globally, 30% of new and remodelled buildings led to health complaints" (Kennedy, Smith & Wanek, 2015 P.13). We call this sick building syndrome. "Government bodies continue to study many of the chemicals added to or used to make building products. Many have declared some of these chemicals to be among the most hazardous known to human kind" (Healthy Building Network, 2008, P.1).
Natural materials are non-toxic and promote healthy indoor environments. Clay is hygroscopic and can balance indoor humidity and temperature. It can absorb pollutants and neutralise odours. It also appears that earth can guard against electromagnetic radiation and influence the ions inside space creating healthy air (Weismann & Bryce, 2008, P.8). Straw is highly insulating and lime with its high alkalinity is a hygienic finish with antibacterial and anti-fungal, mould repellent properties.
In addition to the environmental and health concerns with industrialised building another problem is the cost.
Increased industrialisation and automation does not necessarily bring down the cost of consumer goods. It may help advance the deployment of technology but it also seems to consolidate industries, raise the financial barrier to entry and reduce worker numbers.
"Since the mid-1980's, construction costs have increased phenomenally" in NZ, in the residential sector the 36-year average is "5% pa" (Colliers International, 2016, p.1-2). "The average cost (this excludes land, demolition, external works, connection to utilities, professional and council fees and GST) of building a standard 140 m², 3 bedroom, one bathroom home in Auckland (is) $266,000" (New Zealand Institute of Quantity Surveyors, 2016, para.10). Compare this to a few generations ago when a fully built house with land was around 1/3rd of a typical yearly income. I would like to point out that although based on official data this figure is substantially lower than what we encounter in the field so the difference is likely to be even greater.
This cost increase has occurred in tandem with the technological advances in the residential construction industry, including, pre-nailed frames, pre-made trusses, aluminium joinery, concrete floor slabs, long run roofing and power tools. Going forward under this industrialised model entails more prefabrication. It will be claimed that this will reduce costs, but BRANZ (Building Research Association New Zealand) did a study on prefabrication and found that "improved economic outcomes are not inherent in prefabricated construction" (Burgess, Buckett & Page, 2013, p.53).
Industrialised building means onsite construction is quicker (as much of the work occurs in factories) but it requires specialised skills and tools. This puts it outside the scope of the average person, adding complexity and cost.
Natural building is easy to learn. It doesn’t require expensive, time consuming training nor many specialised tools. It can be done by guided unskilled workers. Natural materials like clay and site harvested timber are inherently cheap and most of the cost when using such resources is in the labour. Therefore if you want to reduce the cost of natural construction an owner can do a large part of the work themselves as an 'owner builder' and use guided unskilled support labour at fair rates. Economically it comes down to where you want to spend your money, with large remote companies making industrialised materials or directly with your fellow community builders.
For all the benefits attributed to mass produced, industrialised housing, the simple fact is that over time, along with increased industrialisation, our buildings have become more expensive, toxic and polluting. At the same time community labour has increasingly been replaced with offshore factory labour and local skills and crafts have been lost. We believe the solutions can be found in natural materials and traditional low tech, easy to learn techniques that are better for us, our community and the planet.
This country was founded by people, both Māori and European, who built their own homes. They did so with natural materials and traditional techniques. Let's revive this philosophy and together let's help build a better future!
● Burgess, J., Buckett, N., & Page, I. (2013). Study Report SR 279 Prefabrication Impacts in the New Zealand Construction Industry. BRANZ
● Colliers International. (2016). New Zealand Research Report September 2016. Auckland.
● Healthy Building Network. (2008). Toxic Chemicals in Building Materials. Washington, DC.
● Kennedy, J., Smith, M., Wanek, C. (2015). The Art of Natural Building (2nd ed.). Canada: New Society Publishers.
● New Zealand Institute of Quantity Surveyors (2016). QV Costbuilder Data Shows Building Costs Jumped 20.0% During The Christchurch Rebuild. Retrieved from http://www.nziqs.co.nz/News/ID/88/QV-Costbuilder-Data-Shows-Building-Costs-Jumped-200-During-The-Christchurch-Rebuild
● Weismann, A., Bryce, K., (2008). Using Natural Finishes. Green Books Ltd.