A new building is nearing completion on the University campus that is unlike anything else seen in its history. Constructed from an optimised form of cob, the centuries-old material once used extensively for house building, the single-storey facility is set to become a living laboratory, a classroom and a demonstration site for a major cross-Channel research project. We talked to the researchers leading the CobBauge project to find out how subsoil and natural fibre might be the building blocks of a low carbon future.
For centuries, people built their homes from a material called cob.
It’s estimated that 8% of the world’s carbon footprint (Olivier et al., 2016) is owed to concrete.
CobBauge project is a cross-border research project, led by the University, aiming to demonstrate that this ancient technique has a role to play in the future of the construction industry.
The newly created cob mixes were produced from local soils, which the project has calculated will reduce CO2 emissions by around 40% compared to the production of traditional masonry materials. They also reduced construction waste by an estimated 16 tonnes per property, a saving of €2,115 (around £1,700) in terms of landfill costs.
Having proven the concept, CobBauge moved forward to phase 2. We secured further funding from the Interreg VA France (Channel) England Programme and the ERDF for four more years of work, which would involve the construction of two full-sized buildings using the new material – one in Normandy, the other here in Plymouth. Hudson Architects, a UK practice based in Norwich with nationally leading expertise in innovative design, also joined the project team. The location for the Plymouth prototype CobBauge building is adjacent to the Sustainability Hub on campus. In January 2021, our project architect for this building, Fox Ecological Architects, submitted a planning application to Plymouth City Council.
In being approved, the Plymouth CobBauge Building created a new landmark – the first cob building in the UK to be approved under modern regulations.
So, how was it built?
The completed building – a single storey, 30m2 facility – will be a demonstration site for contractors and a classroom for students, who are the industry professionals of tomorrow. There’s no reason that further innovations will not follow, and already it can be seen how it will be possible to build multiple units at once.
Through the CobBauge project, we are addressing the need for affordable, sustainable, energy efficient dwellings. Cob has clear advantages over other materials in terms of the energy needed to construct it and bring it to site, and the construction of these homes will also make use of the traditional skills of small businesses and tradesmen in areas where cob has historically been used. With authorities requiring new construction and renovations that are sympathetic to the historic built environment, there is definitely still a place for them. By developing new methods and training professionals in how to implement them, we can ensure this traditional technique is adapted so that it remains part of the streetscape for centuries to come. Of course, we understand that cob isn’t for everyone, but unless we start innovating, we’ll carry on doing the same thing and a university is a perfect place to conduct this type of real-world experiment.”
Professor Steve Goodhew