Wednesday, April 21, 2010

Sustainable Building Material Approach

Kevin Vervuurt

The Open Source House Project aims at providing better, affordable and sustainable housing for low-income households in developing countries. The outcome of the architectural competition intends to guarantee standards of sustainability and meet the challenge of flexibility, ensuring that all designs can be locally embedded with the ambition that +100.000 people will be living in sustainable OS-housing by 2020.

Here are a few tips for a sustainable, local and affordable approach to building materialization. Despite the fact that these ‘themes’ overlap, they do not necessarily imply each other, hence my reason for mentioning them separately. Initially the Open Source House Competition is focused on the Ghanaian context, but eventually the objective of the entire project lies in providing a solution for developing countries.

Trias Ecologica is an environmental strategy for sustainable development. According to Trias Ecologica the first step is to minimize the demand of sources [e.g. raw materials, water, energy, etc] as much as possible. This already starts in the early stages of the design process, as the form and materialization will for example define its energy usage. At this point it is also important to have a feeling of the amount of materials a design requires, including the construction techniques applied, as the latter might need a lot of extra building elements and or labor.

Secondly in the case of dependency of a source, go for endless, inexhaustible sources. The construction industry creates a lot of waste; certain waste materials can be re-used without needing to be processed and with little effort. For example reusing the wood or bricks of [old] buildings which are about to be demolished. It is also encouraged to use [domestic] materials not stemming from the building industry, in alternative ways for construction purposes.

Only if the first two steps are not enough to meet demand use exhaustible/finite sources as efficiently as possible. Limit your choice to sustainable and traditional building materials which can easily be grown and or manufactured within the local context. In the case of the competition the usage of materials which can be found in Ghana is important, but secondly it is also encouraged to think about building with materials from your local context, which might not be the same. This would allow your design to be applicable within a broader context, from a building material perspective. A Local context is a relative term as its scale depends on several factors e.g. habits, density, infrastructure, etc.

The publication “Small-Scale Production of Building Materials in the Context of Appropriate Technology” from the Centre for Human Settlements of the University of British Columbia emphasizes the importance of employing the local context as part of a development strategy. The document indicates the scale of locality being of central importance for increasing self-reliance and efficiency in housing construction, and aims to build on experiences relevant to solving local needs in locally appropriate ways.

“The UNCHS theme ‘The Small-Scale Production of Building Materials’ therefore is important technically, economically, socially, culturally, and forms part of a development strategy which emphasizes increased self-reliance, efficiency, and above all, builds on experiences which are relevant to solving local needs in locally appropriate fashions. Man’s principal aim in this regard is to enclose space for a variety of human and social needs; to do it as effectively and efficiently as possible, using resources that are readily available and appropriate. This concept is particularly vital in meeting the burgeoning shelter needs of the poor”*

Lastly, as the Open Source House Project is targeted at low-income households the buildings should be affordable. Local materials and technology minimizes production, transportation and construction costs of the building process. A quick, efficient and simple to manage building process can also keep the building costs low.

An economic design strategy can be part of the solution, in which the initial building costs are kept to a minimum by thinking of an expandable unit that is build up in phases; starting with a simple nucleus containing the primary necessities of basic adequate shelter [toilet, shower, living room, external kitchen], which can be extended overtime. The latter can happen with the ‘growth’ of income or after the initial structure has been paid off.

Maintenance costs should be kept to a minimum by the application of user-friendly and familiar construction techniques in combination with durable materials, which can be self-repaired and replaced. Not only does this keep the cost of maintenance low but also promotes self sufficiency.

In the end the proposal should be economically viable for the target group. Cheap materials do not imply of low quality, it is up to us, as designers, to come up with creative, environmentally sustainable and affordable solutions.

*University of British Columbia Centre for Human Settlements, Small-Scale Production of Building Materials in the Context of Appropriate Technology, [p.2], 1986, [http://www.chs.ubc.ca/archives/?q=node/989]

Useful websites:

http://www.sustainablebuilding.info
http://www.humanitariantimber.org
http://www.greenhomebuilding.com

1 comment:

  1. 6-Star energy rating is taking effect in Western Australia on May 1st 2012. The new 6 star energy efficiency regulations are the biggest challenge for builders and architects since the Energy Efficiency regulations were first introduced into the Building Code of Australia (BCA) in 2003.

    Although it is true, the stringency of the energy efficiency regulations for houses has steadily increased since its induction; the change from 5 star energy efficiency regulations to 6 star is requiring builders and building designers to significantly modify their energy efficiency solutions and method of compliance.

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