Key concepts from Construction Materials Selection and Use: An Environmental Guide
Responsible Material Selection and Use: Key Concepts
BY EDM | 02 SEP 2016
Think through the whole supply chain.
Environmental and social impacts from building materials can occur at any point in the supply chain, from sourcing raw materials, through processing and delivery to the site. This includes the social and environmental practices of manufacturers. For example, do working conditions at the processing plant meet responsible standards? Is the processing plant disposing of leftover material in an environmentally and socially responsible way?
The first criterion for an environmentally responsible material is the safety of the structure that will be built with it. Not safe is not green.
Only support sound and legal sourcing of materials.
In large-scale, post-disaster rebuilding, the demand for raw materials can quickly outstrip the supply of sustainably produced natural resources, such as clay for bricks, sand for cement, and wood for timber. For example, unsound excavation of clay or clear felling of timber on steep hillsides to rebuild hundreds or thousands of houses increases the risk of landslides and topsoil erosion. Such environmental damage can increase risk and jeopardize the success of the overall recovery effort. Project managers should be aware of the sources of their building materials and make sure that they establish contract specifications for the use of sound and legally sourced materials. Using materials that have been credibly certified can be one strategy for ensuring that materials have been sourced sustainably. Material sourcing, processing and use should be socially equitable. Any form of material sourcing that puts disproportionate burden on women, children, differently abled or socially marginalized people is not sustainable. Furthermore, material sourcing should not disturb the established local livelihoods.
Design to use fewer materials and reduce waste.
In designing structures such as houses, project managers should consider ways to effectively meet humanitarian needs with fewer materials. Reducing packaging materials and designing structures with standard material sizes can help to prevent waste of materials during the transportation and construction phases. Designing structures and specifying materials for optimal design rather than either overengineering or creating rigid requirements can reduce material waste by allowing some flexibility in construction and in material options. For example, if one material or size is not available locally another can be used in its place to achieve optimal design instead of importing additional materials to fit a very specific requirement. Following material-specific storing and handling guidelines helps extend the shelf life of materials and ensures that materials are not damaged and need to be replaced.
Use local sources - where this can be done in an environmentally responsible way.
Local procurement of materials can be a more environmentally sound strategy than the procurement of distant materials through reduced carbon emissions from transportation and natural resource use in packaging. Give priority to materials selected or processed with traditional knowledge. When using local materials, however, project managers should make sure that extraction, processing, and use do not put peoples health or environment at risk.
Use disaster debris as a reconstruction material.
One of the most environmentally sustainable options for construction projects in a post-disaster setting is the reuse of building materials found in disaster debris. If using disaster debris, project managers must ensure that the debris meets applicable specifications for strength and safety.
Use materials with recycled content and recycle.
Materials with recycled content are widely available, one example is cement produced with fly ash from coal-fired power plants. Project managers should consider using building materials with recycled content where practical to reduce demand on natural resources and lower the projects human and environmental impacts. Leftover material or material packaging should also be considered for reuse, repurposing, and/or recycling.