Intensive, integrated, Biomass-based material and energy systems: Swedish experience

Sustainable development of the built environment requires the production of increased quantities of construction materials and energy services, produced within the constraints of natural systems. This paper presents recent findings from Sweden on the intensive use of renewable forest resources within integrated material and energy systems. Production of materials for wood-framed construction uses less primary energy than for comparable reinforced concrete construction. Multiple wood-based products can be co-produced from the forest biomass, increasing the efficiency of raw material use. Biomass by-products from the entire wood product chain, including forestry, wood processing, construction and demolition, can be recovered for use as biofuel. The biofuel energy available over the life cycle of a wood-framed building is greater than the primary energy used to produce the materials. Increasing forest management intensity gives greater energy returns on management energy inputs. Intensive production of forest biomass is maintained by closing nutrient cycles through application of wood ash and nitrogen fertiliser.