The first super-insulated, ultra low-carbon straw bale houses to be made available on the open market have gone on sale, amidst a flurry of media attention and references to a certain porcine fairy tale.
The seven two and three-bedroom homes in Shirehampton, Bristol, which are being built with developer Connolly and Callaghan, are the product of 13 years of research by University of Bath’s department of architecture and civil engineering into straw as a low-impact building material. This work, which has included developing a straw bale panel as well as scientific monitoring and testing, has now culminated in key industry certification. BM TRADA’s Q-Mark certificates a straw building’s energy efficiency, fire safety, durability and weather-resilience and means that developers and homebuyers can now get insurance and mortgages for straw homes and buildings.
The walls of the house have been built using ModCell technology; prefabricated panels consisting of a wooden structural frame infilled with straw bales or hemp and rendered with either a breathable lime-based system or ventilated timber or brick cladding. The technology has been tested and applied in a house, BaleHaus, on the University of Bath campus and in the LILAC co-housing development in Leeds. The latter project, which comprised 20 homes, resulted in a reduction in energy usage of up to 90%.
Professor Pete Walker, head of the department of architecture and civil engineering at University of Bath said, “The construction sector must reduce its energy consumption by 50% and its carbon emissions by 80% by 2050, so radical changes are needed to the way we approach house building”, he said. “As a construction material, straw is a low-cost and widely available food co-product that offers real potential for ultra-low carbon housing throughout the UK. Building with straw could be a critical point in our trajectory towards a low-carbon future.”
The homes are being marketed via estate agent Haart.