Wood helps to minimize energy consumption in several ways. In terms of embodied energy, which includes the energy required to extract, process, manufacture, transport, construct and maintain a material or product, life cycle assessment studies (LCA) show that wood significantly outperforms both steel and concrete.
This chart is based on LCA calculations for identical 2,400-square-foot homes designed according to standard local practice. The wood house had less embodied energy than the concrete or steel-framed structures, and the concrete structure had the highest embodied energy. Operating energy was comparable for all three.
Source: Athena Institute, Canadian Wood Council, Morrison Hershfield Engineers, 2004
In terms of operating energy, wood has the advantage of low thermal conductivity compared to steel and concrete. As a result, wood is easy to insulate to high standards while steel and concrete must overcome problems from thermal bridging and the possible consequence of moisture condensation on cold surfaces. However, because there are many factors that have a greater influence on a building’s energy efficiency (such as insulation and air tightness), the more relevant point for many designers is that wood building systems lend themselves to structures that are highly energy efficient—with less impact on the environment in terms of embodied energy, air and water pollution, and carbon footprint.
Any wood structural system can be designed to achieve a tight building envelope. However, with new systems such as cross laminated timber (CLT), precise manufacturing results in tight tolerances and exceptional air tightness. The added aspect of dimensional stability also ensures that the building remains airtight over time. Wood is also proving to be a good choice for designers who want to meet the Passive House (Passivhaus) standard or create a net-zero energy or net zero-carbon building.
- Environmental Performance of Renewable Building Materials in the Context of Residential Construction – Consortium for Research on Renewable Industrial Materials (CORRIM)
- Energy and the Environment – Canadian Wood Council (CWC)
- Thermal Performance of Light Frame Assemblies – CWC
- Wood Specification: Passive Design and Framing Techniques – naturallywood.com