Clayfest 2020 | Print |

Traditionally straw bale construction involves plastering the walls once the bales have been erected into place. In more developed countries the plasters are often sprayed on. This requires machinery and skills that are scare in developing economies like South African. So both from an ecological perspective, as well as from the need to create local employment opportunities and build self-reliance, labour based plastering methods are preferred. However, plastering onto a straw surface can be very time consuming and the results often far from satisfactory, where the walls still sound hollow and require lots of mesh reinforcing to first stiffen up the surfaces.

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In response the author has developed a system that combines the durability and solidity of cob with the speed and insulation of straw bale by using an earth slip pre-coated straw bale plastering system. When one uses this cob-bale method, the speed of it is such that one can complete sections of the wall panel by panel in a single day. As such the walls are also immediately better protected against any risk from fire or rain during construction. Cob bales are of a much more solid and stable nature, where one is able to get the base coat to penetrate 70mm or so into the surface of the bale with a minimum of effort. The speed and solidity of this system is particularly attractive for participatory building processes.

Speaker Qualifying as an architect at the University of Cape Town in 1995, he presented at South Africa’s first Sustainability in the Built Environment Conference, in 1998 “a Manifesto for Green Architecture – 6 broad principles for a greener architecture”, which formed the basis of his practice; ECO DESIGN – Architects & Consultants. Widely recognised for his pioneering work in the field of green building in the South African context, with a special focus on using local natural & recycled building material & community participatory processes, Horn has acquired a number of awards including, a 2004 Sustainable Building Best Practice Award in 2005, the Silver medal in the Holcim Awards for Sustainable Construction in the Africa & the Middle East region & qualified as one of 15 finalists in the 2006 Global Sustainable Building Holcim awards. He has served a wide range of clients from all around Southern Africa, including governmental, institutional & NGO based clients, the resort & leisure market as well as residential & owner builder clientele. He has written numerous articles, published papers & exhibited both locally & internationally. He also gives lectures & holds participatory design charrettes as well as facilitating straw and earth building workshops.