If you’re looking for a unique, eco-friendly method steeped in history to build a home, you might want to look more closely at cob houses.
Cob is an ancient building technique used around the world since prehistoric times. It’s fascinating to look at the history of cob houses — from ancient times to the present day.
More than 1.5 billion people (approximately 30% of the world’s population) live in earthen structures like cob houses, proving that cob homes are not just part of our past, but have also endured into the present.
Cob building has experienced a resurgence in recent years as eco-conscious individuals look for sustainable construction techniques so they can do their bit for the environment.
In this article, I’ll discuss the history of cob houses. From ancient times to modern-day cob house construction, you’ll learn more about this fascinating technique. So, let’s begin!
Cob house construction dates back to the 11th and 12th Centuries.
Although the term “cob” was first used in Cornwall in 1602, cob houses were being built in different places under different names.
Most of the oldest structures in Afghanistan, Africa, Wales, and most of the Middle East countries were made from cob.
Ibn Khaldun, an Arab historian, documented the evidence of cob construction in the 11th and 12th centuries. He describes cobwork (tabya) in al-Andalus and Maghreb.
Although the exact time when cob construction emerged in England is unknown, it’s believed that the technique was already in use by the 13th century.
It’s believed that cob construction in England emerged from the wattle-and-daub technique.
Wattle-and-daub was a building method that involved plastering mud on a framework of woven branches.
The wattle-and-daub technique was the basis for the idea of cob construction. Filling in between the wattle walls with mud meant the building remained firm even after the wattle decayed.
Another theory explaining the origin of cob construction in England holds that the technique evolved from the Medieval mud mixture used in mortar stone walls.
During ancient times, mud was crucial for mortaring stone walls to fill the cavities between stone faces. The mud was made from soil, straw, and water.
The same mixture was used for cob construction to hold together the walls.
Later on, cob houses replaced wood as the primary building material because it offered excellent protection against decay and fire.
Cob construction was prevalent in Southwestern England. The sandy clay of the subsoil in this region made it easy to mix with water and create cob.
In addition, the UK’s wet climate was ideal for creating mud, which meant that cob construction flourished in this region — and still does today.
Cob houses became the norm in Britain in the 15th century.
According to the University of Oregon, cob was used by the peasants and the wealthy in Britain to create dwelling units.
In Britain, cob construction involved shoveling stiff mud onto a stone foundation. After that, workers came in to tread the cob, which involved compressing the mud with their feet and making it into walls.
The walls were built in courses, with each course left to dry before adding the next one.
The walls were then trimmed, and lintels were added for later openings like windows and doors. Some homeowners plastered their cob walls with lime or a clay-sand render to keep dampness and cold out.
Cob building remained integral to house construction in Britain until the 1800s. This era was when cheap transportation was invented, popularizing brick and concrete. These materials also became more affordable and readily available.
British settlers played a crucial role in the spread of cob construction.
They brought this technique to North America to build their dwelling units.
The material was also used to construct other buildings like churches and barns in different parts of the United States, Canada, Australia, and New Zealand.
For instance, the colonists found favorable clay soil and tussock grass for building cob houses in New Zealand. Consequently, they built over 8,000 cob houses, of which several hundred still survive.
There still exists a cob house built in 1836 in Penfield, USA, and a church in Toronto, Canada.
Cob houses were particularly popular during the colonial era because of their low cost, flexibility, and durability. The material was also readily available in the colonies, making it a preferred choice for constructing dwellings.
Why do you think cob is considered an alternative building material?
This is because the use of cob for construction declined in the 19th century when brick and concrete became more affordable.
In addition, building codes worldwide were not set up to accommodate this type of construction.
During the 19th and 20th centuries, cob construction was considered a primitive and backward technique in England and the U.S. Consequently, it started declining in popularity.
Most people started considering brick and concrete as superior alternatives. This explains why virtually no new cob houses were built in England between World War I and the 1980s.
Due to the dormancy in cob house construction, traditional builders took their specialized knowledge to the grave. This contributed immensely to the near-extinction of cob construction.
Although cob construction declined during the 19th and 20th centuries, it has gained momentum since the start of the 21st century.
This is partly because people are becoming more aware of green building techniques.
In addition, cob is an affordable, low-impact option for building a strong and comfortable home.
The resurgence of cob construction has been driven by the need for low-cost housing, a heightened awareness about sustainability, and a desire to preserve our environment.
The revival of cob construction today is evidenced by the approval of a Cob Construction Appendix for inclusion in the International Residential for Building Codes in 2020.
Besides the efforts by the Cob Research Institute (CRI), the following are some renowned sustainability enthusiasts who contributed to the revival of cob construction:
- Kevin McCabe: In 1994, he built the first cob residence in England in 70 years. It was a two-story, four-bedroom house built with cob mixed using a tractor.
- Rob Hopkins: He built a cob house for his family in Ireland between 2002 and 2004. It was the first of its kind in the country in 100 years.
- Associated architects: They designed and built a four-bedroom modern cob house in Worcestershire between 2000 and 2001 in England. They later sold it for £999,000.
The Cob Cottage Company in Western Oregon plays a central role in the revival of cob construction in the United States.
After witnessing earthen construction in Latin America and Africa, Ianto Evans, one of the founders of the Cob Cottage Company, realized its potential for modern living and began promoting it.
At first, Ianto and Linda, his partner, relied on loaves of stiff mud for building. However, as time went by, they enhanced their cob construction materials by giving much attention to mixture proportions and the quality of the ingredients.
While cob builders in ancient centuries used whatever soil they had with little amendment, the Oregon cob is made by importing high-quality sand and clay for the hardest and most reliable mixture.
Due to technological advancements and the use of tests like the mason jar test, the modern cob is highly reliable and robust. This cob is used to build more sculptural, stronger, and narrower walls 18-24 inches (46-61 cm) thick.
Final Thoughts On The History Of Cob Houses
Cob construction has come a long way since its early beginnings in ancient times.
It has gone through periods of dormancy, revival, and technological advancement to become an efficient and reliable building technique.
Consequently, you can rest assured that cob houses are here to stay. This is good news if you’re concerned about our environment because cob construction is a low-impact way of building solid, comfortable homes.
As an eco-conscious builder, you might be interested in our article on 29 sustainable building materials you can use today.