Using local materials in buildings benefits the community, the local economy, and the Earth. Buying local materials reduces the carbon footprint of construction: the less a material has to travel to the building site, the fewer fossil fuels are burned in the delivery of the material.
The Living Future Institute refers to this as the Living Economy, requiring living buildings to source 20% of materials from within 500 km of the building site, 30% within 1000 km, and 25% within 5000 km. Consultants must come from within 2500 km of the project location.
The map above is the work of Hampshire College students looking at materials sourcing for the R.W. Kern Center.