The Construction Sector have developed a roadmap for reducing built environment carbon emissions by 50% by 2025, which will contribute to national carbon emissions reduction targets net zero by 2050. As energy efficiency of buildings has improved significantly, there is a growing interest in the embodied carbon of the buildings themselves, in addition to the operational carbon which has been the primary focus until this point. This paper reports a study which was undertaken to compare the embodied carbon of timber framed and masonry residential structures. The work indicates a significant benefit per dwelling for timber framed systems. This was in line with previous studies using different building designs and different functional units.

Embodied carbon is the carbon associated with the input materials and manufacture (including processing, transport, etc.) of a product, as well as later demolition, recycling or disposal. It is possible to determine embodied carbon for single materials or for whole buildings. BS EN 15804 is a standard for evaluating and comparing the Environmental Product Declarations of building materials, and guidance to the industry for applying this data within calculations for buildings has been developed by RIBA and RICS. However, many factors influence the ability and willingness of companies within the sector to consider and apply these new calculations when designing new buildings.

Timber and wood based panels in structures are an especially interesting element within the discussion of low carbon construction, due to their multiple different roles. The study demonstrated that timber structures can reduce embodied carbon of a building, in addition to providing a long-term storage role for biogenic carbon, i.e. the carbon sequestered in the forest, but stored in the built environment. Using a stocks and flows approach to carbon storage in buildings offers insight into the potential role of timber and wood based panels in long term storage of carbon. It also offers an opportunity to compare carbon accounting within bioenergy (short cycle) and long cycle systems. A discussion on wood industry co-products and wood waste from demolition, and carbon accounting for their role in bioenergy or energy from waste is timely.

This paper considers the importance of wood based panels in modern methods of construction, such as timber frame and SIPs. It also highlights the role of wood based panels in reducing the embodied carbon of new build dwellings.