The European Union aims to reduce energy use by 20% by 2020 (2012/27/EU). A major obstacle is reducing the energy used by EU buildings’ construction and use, which currently consume 40% of generated energy (EU2010).

Besides cob* buildings are common in the Channel regions but do not meet current thermal regulations as the current thermal conductivity of the material is around 0.7 W/mK, close to medium density concrete, while it has to be around 0.3 W/mK, close to lightweight concrete (Goodhew, 2005). The material’s thermal insulation value needs to be increased whilst maintaining structural durability through the use of fibres.

Moreover, local planning requirements require new construction and renovations that are sympathetic to the historic built environment, much of which is cob and earth. By creating new inexpensive cob technologies that meet building standards (Code de la construction et de l’habitation, 2017 ; UK Building regulations, 2016), local and national building firms and consumers can meet planning, environmental and financial challenges.

Thus, to help meet this challenge, CobBauge will develop, test and establish an innovative low carbon cob technology using local soil and agricultural fibres/waste fibres from industry. This technology will contribute to the reduction of CO2 emissions, improved energy efficiency and cost savings over 10 years by:

  • creating an inexpensive, well-insulated material, using less than half the heating energy to heat a cob house compared to traditional building methods (McCabe, 2017)
  • reducing construction waste by 16 tonnes, thereby saving in landfill costs
  • Requiring minimal transport costs (using local suitable soil), reduced embodied carbon of 4 tonnes CO2e per house (Li, 2012).

To do this, the CobBauge project involves five British and French partners with complementary expertise:

  • Plymouth University (UK) : Lead partner of the project
  • Ecole Supérieure d’Ingénieurs des Travaux de la Construction de Caen, ESITC Caen (FR)
  • Regional Nature Park of the Marshes of Cotentin and Bessin, PnrMCB (FR)
  • Earth Building United Kingdom and Ireland, EBUKI (UK)
  • University of Caen Normandie, LUSAC Laboratory (FR)

The CobBauge project was selected under the European cross-border cooperation Programme INTERREG V A France (Channel) – England co-funded by the ERDF.

Duration of the project: 07/2017 – 03/2019

Total budget: € 1,097,485

ERDF co-financing: €757,265 (69%)

*Cob is a mixture of earth and fibres, such as straw, which is then mixed with water and used to construct buildings.