What is Cob?

Cob is a structural composite of earth, clay, straw and water that is hand-sculpted while it is still pliable, into fireplaces, ovens, bus-shelters, schools or indeed houses. The possibilities are endless! It is non-toxic, non-polluting, 100 percent recyclable and biodegradable and uses little energy in extraction or deconstruction. Best of all, the clay subsoil produced in extraction of the trenches is often the best source of clay for the cob mix.

It is one of the oldest, safest and most eco-friendly methods of building. If mixed carefully, well-maintained and protected from moisture with ‘a good a hat and a good pair of boots’ – roof and stem-wall – it will last indefinitely.

The oldest standing cob building in the UK dates back to the late 1200s. Cob became the norm in many parts of Britain by 1400s – particularly in Cornwall, Devon and Wales, where the subsoil was especially rich in clay – an essential ingredient for the cob mix. There are hundreds of these old houses still in existence.

The word cob comes from an Old English root, meaning a ‘lump or rounded mass’. In Wales, the word is still used to describe a lumpy horse (cob pony) and a certain type of bread (cob loaf). It refers to building that uses no forms, no bricks and no wooden structure. Using little ‘lumps’ of cob mix, it is built up in ‘lifts’ to make a monolithic mass of earth.

Building with cob is about getting your hands (and feet) dirty: cob mix can be stamped by bare or wellied feet, horses or, where workforce smaller and quantities larger, by tractor. It can be a squelchy and very enjoyable experience.

By assessing the suitability of the resources that you have close at hand, working around the seasons, and getting people (anyone!) involved with helping building, it is possible to build a house out of cob without using any machinery at all. We are currently experiencing an eerily peaceful building site in Stoke Newington. Several excellent books have been written about different ways of building with cob.

Cob is also completely non-discriminatory! It is accessible to people of all ages, abilities and backgrounds.

As it doesn’t need straight lines for any kind of framework, cob lends itself particularly well to curved walls, arches, vaults and more natural and organic lines. This curviness has been explored extensively and experimented with by the Cob Cottage Company who have made ‘Oregon cob’ a sub-group that is partially defined by its disregard for the right angle. Not only does this give a gaudi-esque effect to the buildings, it also provides much of the structure’s strength.

Welcome to the cob renaissance. Rather a grand term for what is effectively a return to building mud huts perhaps. Nevertheless, since the 1980s, fuelled by historical interest and the real estate value of ancient cob homes, this style of building, which presumably became unfashionable in favour of more modern looking buildings, has made a come-back and, thanks to several cob writers, it has been encouraged as a perfectly financially viable, enjoyable and relaxed method of self-build.