The tumbledown house renovation
Even in this age of house price inflation the number of properties that are allowed to fall into disrepair is surprisingly large. The Ecology is a specialist in renovation mortgages, helping bring property back into use - a form of recycling.
Ecology borrowers like Christopher and Jane needed a great deal of imagination and determination when they embarked on their particular renovation project. They bought a neglected Grade II Listed cottage near Bridgwater in Somerset at auction in May 1998, which had been practically burnt to the ground by fire a year earlier. They applied for a mortgage with the Ecology a few months after the purchase, to fund the massive reconstruction.
The restoration had to comply with its listed status and the District Council Planning Authority, who required the cottage to be repaired using traditional materials and be as close to the original layout as possible. The original remnants of the cottage date back to the 17th Century when it was reputedly a Miller's cottage. The cottage is primarily constructed of cob (see Building with cob) and stone walls, under a thatched roof.
Due to the extensive structural failure caused by the severe fire and subsequent water damage only the lower parts of the walls and the chimneys were still standing - and then only just!
Our intrepid members were not phased by the scale of the project. Having run their own successful civil engineering business for many years, they were able to take a significant 'hands-on' approach to the reconstruction, which began in July 1998. What they didn't know they quickly learnt along the way.
Christopher and Jane made their own cob blocks in-situ from material excavated from the building site and wheat straw. They were assisted by a local cob and lime mortar specialist, who trained and supervised the people involved. The cob was pointed and rendered using unhaired lime mortar and structural timbers of seasoned oak and elm were sourced locally.
The before and after photos illustrate what a mammoth project Christopher and Jane took on. Using reclaimed and ecological materials they have rejuvenated a pile of rubble into an idyllic chocolate box cottage. It is estimated that there are 40,000 listed cob buildings in the UK, as we have seen some are just crying out for help.
For further information on traditional and sustainable earth building contact The Society for the Protection of Ancient Buildings who run a mixture on practical workshops and lectures on building with earth, including cob, rammed earth, wattle and daub and clay lump.
Building with cob
Earth is probably still the world's commonest building material. It is estimated that one-third of the world's population live in earth buildings and that nearly all buildings in the world have some form of basic earth ingredient in their structures. Earth as a building material has a low environmental impact, it uses minimal energy (e.g. no firing is required) and it is recyclable, therefore earth is probably the best ecological material that exists for building!
The word cob comes from Old English, meaning a lump or rounded mass. Cob building uses hands and feet to form lumps of earth mixed with sand and straw, a sensory and aesthetic experience similar to sculpting with clay. Cob is easy to learn and inexpensive to build. Because there are no strict rules or uniform bricks, cob lends itself to organic shapes such as curved walls, arches and niches. Earth is a good insulator, keeping buildings cool in summer and warm in winter. Cob's resistance to rain and cold makes it ideally suited to cold climates and to desert conditions.
Lime renders and mortars are generally used as finishes because of suitability and compatibility with cob. In contrast to cement or silicon sealants, lime render allows the cob to breathe and retain a natural moisture level i.e. dry out when wet and retain moisture in dry atmospheres. The old saying of cob requiring "a good hat and good boots" is true. The "hat" being a good, tight roof with a minimum 200mm overhang and the "boots" a stone plinth to provide a good base. If this can be achieved then the cob will become waterproof and remain dry and sound.
Advantages of Cob as a Building Material
- Low environment impact
- 100% recyclable and biodegradable
- Easy to learn
- Inexpensive
- Minimal transportation
- Quick construction
- Versatile
- Good insulation properties
- Adaptable to any climate
- Healthy, non-toxic
- Requires manpower not machine power
- It is free and abundant
