Structural Potential of Excavated Earth

This technical lecture explores the core principles of regenerative design and how utilising site excavation for load-bearing purposes can transform the construction industry. The lecture highlights Earth as the only truly local construction material.

Load-bearing earth buildings can last longer than 700 years and reach more than 25 meters high. At an age where sand and gravel resource depletion puts even greater pressure on dwindling supply chains, we need to reimagine excavation soils as building material rather than waste. Earth’s thermal mass and hygroscopic properties offer a superior internal building fabric which can significantly lower energy demands, improve humidity levels, and enhance thermal comfort. The combination of locally obtained earth with natural fibres such as straw and hemp shive presents one of the most sustainable solutions we have.

DSDHA teamed up with Webb Yates and Atelier Ten to test the design of a five-storey terraced building using mostly earth and natural fibres. The prototype, which will be presented for the first time during the talk, challenges our current structural and environmental understandings of what is possible with earth, demonstrating the potential for significant operational energy and embodied carbon reduction when constructing medium-rise buildings.

This lecture aims to demonstrate the untapped potential of site-excavated earth for load-bearing and non-load-bearing purposes. It will help you understand how the Earth plays a pivotal role in the process of decarbonization of the construction industry and the key principles of regenerative design, including:

• regenerative design principles
• structural use of earth
• overcoming the low flexural strength of earth blocks and mortar
• pushing the building envelope closer to a no-heating/no-cooling design