Energy and CO2 Advantages of Wood for Sustainable Buildings

This paper demonstrates the advantages of using wood materials for the design of sustainable buildings in New Zealand, providing national benefits of reducing fossil fuel energy consumption and CO2 emissions. The relationship between fossil fuel energy consumption and CO2 emissions is described, along with the importance of forestry in helping countries like New Zealand to meet their Kyoto Protocol obligations. Wood-based building materials have much less embodied energy than other materials, but this paper shows that the biggest advantage of using wood is the opportunity for recovering solar energy from wood waste, a significantly greater benefit than both the stored carbon and the low embodied energy in wood materials, combined. This energy can be used in place of fossil fuel energy, hence reducing CO2 emissions. Wood waste can come from all stages of harvesting and processing, and construction and demolition of timber buildings. The paper describes current assessment tools for sustainable buildings. Compared with other materials, wood-based building materials score very highly for most sustainability criteria, but are penalised in the proposed New Zealand sustainability assessment scheme which places too little emphasis on energy consumption and CO2 emissions in the life cycle assessment of building materials. This paper also describes opportunities for much greater use of timber and engineered wood products in large buildings, using innovative technologies for creating high quality buildings with large open spaces