Decarbonising construction using renewable photosynthetic materials

Abstract

The need to reduce CO2 emissions from the operational energy used in buildings is more pressing as we seek to mitigate the effects of climate change. As we do so, the ratio of embodied emissions increases compared to operational energy emissions. The use of bio-based materials in construction might allow us to tackle both operational and embodied CO2 emissions. The ModCell Straw Technology system achieves this by using the renewable materials timber and straw. The ModCell system has been used commercially on over 40 projects across the UK and secured a whole build system Passivhaus Component Certification in February 2015. ModCell not only uses renewable materials that deliver a 90% reduction in emissions from heating and cooling, it also delivers an effective carbon capture and storage solution (CCS). Bio-based renewable materials are created through photosynthesis. Plants are able to grow through the conversion of atmospheric CO2 into useable carbon. Powered by photosynthesis, plants absorb atmospheric CO2, deconstruct the molecule into its component atoms, carbon and oxygen and bank the carbon into complex sugars, the building blocks of cellulose. This natural CCS process allows us to exploit the physical properties of straw and timber to build with carbon. The amount of CO2 banked into the system is more than is emitted through its making, resulting in a carbon negative footprint. This CCS mechanism means we can consider the built environment as a man-made carbon sink-the planet’s sixth carbon sink. This approach is supported at a European level by funding from the EU’s Horizon 2020 programme via the www.IsioBioProject.com. The ISOBIO project proposes an innovative strategy to bring bio-based construction materials into the mainstream. The use of bio-based aggregates for construction, which include insulation materials, hygrothermal and moisture buffering materials, binders, sol-gel and bio-based resins, will help create a decarbonised and healthier built environment.