A holistic view on Cob Building


Why do we need cob and other sustainable building methods now?

What is COB?

Examples of cob buildings elsewhere

What areas within the school curriculum overlap with sustainable building methods?

How will working with cob as a school project benefit the children?

What is our proposal?

Why do we need cob and other sustainable building methods now?

Introduction by Sir David Attenborough

It is my belief and that of others that until we find love for the natural World we will not treat CC with the urgency it needs. We will not look for those “levers” which set us free.

Could Cob building be one such lever²?

For many starting out in life, a life choice may be to one day, own their own home. The cost of housing today in the UK is beyond the reach of many and supply does not meet demand. Rental costs for homes is also high and beyond the reach of many looking for their first home, especially in our major cities. The pressure to get that high paid job and take that long commute is hardest on our young people already saddled with student debt and having of a family of their own. Could a solution be to build a sustainable home, where the building material lies under our own feet? There remains the question of land being suitable and being made available for sustainable housing. Until we realise that we all have it in us to build our own home and all that we need is to unleash that innate ability, we are unlikely to organise and put the pressure required on Government to affect change to make that land available.

What is COB?

Rob Alcock:

“Cob is such an amazing material. It’s very simple—a mixture of clay, aggregate (sand), fibre (usually straw) and water”.

Fig 1 Treading cob ( cob dancing)

treading cob.png

Resurgence of cob, dance party by Rob Alcock to compact the sub floor of his new “Snail cabin”

resurgence of cob dance party

Next cob please!

throw a cob.png

Examples of cob buildings elsewhere

What might such a building look like?

Many people investigating cob may have come across the book “The Hand Sculptured House” by Ianto Evans, Michael Smith and Linda Smiley. Below is a picture of the “Heart House” showing the Passive solar front elevation. This was the first building that Ianto and Linda constructed.

Heart house passive solar.png

Heart window on the left.

heart window.png

Michael Smith’s House – Interior: note natural and non-toxic finishes including lime wash around windows and aliz clay slip

Heart Hs interior 2.png

Student build project: Dawn view

Cob Cottage co dawn

Dusk view

Cob Cottage co

What might the cottage look like inside?

Inside cob cottage 1

Ianto Evans and Michael Smith, co-authors of The Hand Scultured House, in one of their students projects.

Ianto and Michael.png

Rob Alcock, “Power of keeping it small”.

Snail cabin built as a learning project.

snail cabin.png

What areas within the school curriculum overlap with sustainable building methods?

What do we need? Clay soil on site, the right climate,  volunteers. An openness to making mistakes. Mistakes will be made along the way, we should not be afraid to make mistakes because experimentation is a natural part of learning.

Thomas Edison (January 1921 issue of American Magazine)

“After we had conducted thousands of experiments on a certain project without solving the problem, one of my associates, after we had conducted the crowning experiment and it had proved a failure, expressed discouragement and disgust over our having failed to find out anything. I cheerily assured him that we had learned something. For we had learned for a certainty that the thing couldn’t be done that way, and that we would have to try some other way.”

Cob building is a diverse learning experience:

Dance the space, image by Ianto Evans

Dance the space.png

“Use your whole body to translate your imagined layout into actual steps in space.”

There is a theatrical element of acting out each living space in the building which can then be translated into what space do we need to contain those aspects of living. The movements shows us how we weave together the individual spaces into a whole building.

Material science

Image from Ianto Evans.

material science

Clay, sand, straw and rendering materials used in cob building are all natural. They come in all colours, and sizes. How we put these materials together, in layers, will affect the cobs compressibility, elasticity and rigidity. We need to know the cobs ability to withstand weight of the roof or upper floor, how cob walls breathe. We might want to retain heat inside the building and heat capacity and retention is a fascinating area of research. For example a trombe wall uses a combination of thermal mass with glazing to store the solar radiation.


Many years ago during an OU summer school, we were asked to make a mathematical model of the time and energy required to bring a kettle to the boil. I recall second order differential equations and we were still no closer. Similar considerations apply for cob. Here is a publication looking at the thermal properties of cob building.


The science and art of growing plants. In contrast to agriculture does not include large scale crop production. The environment surrounding the cob building and its roof, may well provide great synergy for horticulture and an opportunity to apply horticulturists knowledge.



The geography / geology issues raised when considering cob are many fold. We need to make the best use of the solar heat provided and we need to consider the drainage to keep the cob “foot” dry. We need access to soil which contains a source of clay and to consider constraints on lighting from surrounding trees. The likelihood of flooding and celestial orientation need investigation to consider sun light elevation.


We have already described the need for students to understand the psychology of dissonance. With this understanding and that dissonance applies to each of us, the students can reframe the way they self justify their behaviour and work towards ways of reconciliation.

A self organising structure implied by the nature of cob building provides a fascinating insight into how we can best organise a work group and experience how effective and capable it is at delivering the final product.


A cob building can be a thing of aesthetic beauty. There is the opportunity to sculpt, awaken the senses of touch and smell. Experience how we perceive and interpret unusual lighting on unfamiliar surfaces with earthen colour and texture. Being in a cob building can be a form of ecstasy. The thick walls reduce background noise levels opening up our senses to sounds which are often drowned out.


Anyone considering mindfulness or other alternative therapy would find the experience of simply “being” within a cob building a useful environment in which to practice.


Cob building is something that everyone can participate in. The safety aspects are greatly reduced. Each “cob” has a weight and softness that even small children can cope with. Conventional building sites have dangerous machinery in operation and many of the building products are toxic in nature. Cob building uses basic hand tools and natural materials. Even so, design and construction can offer new exciting and challenging opportunities for anyone anticipating going into building trades.


Cob and mud brick ( Adobe )homes have been used throughout the centuries, all over the world in construction of buildings such as the city of Shibam in the Yemen or the Great Mosque of Djenne in Mali shown below. Perhaps an insight into the construction methods used in these building, their working history, can be gathered by making our own cob building?


How will working with cob as a school project benefit the children?

Cob can enrich our lives:

Cob construction work is dirty, squidgy, labour. It has a pace which can be harmonious with good living. All cob building is a form of experiment and learning and if the result is not what was supposed to be, cut back to where things were going to plan. The work is mainly outdoors but much preparation work can be done in the lab or school rooms currently used for that subject carrying out cob experimentation. Cob building can be “owned” by the people doing the work and from others who experience the process, it helps to give a sense of bonding to the environment local to that building. Cob building is a natural process using natural materials unlikely to cause harm and suits a wide age range who can be involved.

Cob can empower the young people to reframe their perception of the challenges their generation is facing:

Cob offers one of those “levers²” to help look at those challenges full on. Learning during building, provides space to look at other “levers” which help mitigate mans harmful effects on the Natural World.

Building cob confidence:

Experiencing the building grow, knowing yours are one of many pairs of hands working as a team to make this happen, surely can be good for any student. Taking that sense of ownership and having pride in playing your part in design, production and discovery, I suggest will be a welcome attribute to take with that student into their future work lifes.

A place to return to:

Perhaps during exam times or when feeling personal stress or when the students resilience is at a low edd, the cob building could be a retreat, a place of sanctuary to help rebuild that inner strength.

A place of reflection:

The building could be videoed or pictures taken which allow a historical reference for future expansion should that be though necessary. The history of the cob project could go with the student involved in that cob building as a reference and as a source of inspiration as they move into adulthood.


Some of the material has been lifted from other sites:

I would like to acknowledge in particular:





I propose a key to some of the answers to the problem set by Sir David can be found in psychology and in particular, Dissonance theory , as discussed in Carol Tavris and Elliot Aronson’s book “Mistakes Were Made” details the workings of psychological blind spots. “It would seem that one of the minds cleverest tricks is to confer on us “we” don’t have a blind spot”. To understand why dissonance applies in the context set out above we first need to understand the term “learned helplessness”.

2..Learned Helplessness

Taken from “The Choice” by Edith Eger.

Pg 223    Edith a survivor of the holocaust, recalls work by one of her university mentors, Martin Seligan on dogs, which preceded protections on animal cruelty.  The experiment answered a question for Edith which was that, since the liberation day at Gunskirchen Austria in May 1945, why did so many inmates wander out of the gates of the camp only to return to the muddy, festering barracks? Psychologically what was at work to make a liberated prisoner reject freedom?

To find out more please refer to the work by American psychologist Martin Seligman who initiated research on learned helplessness in 1967 at the University of Pennsylvania


So where does dissonance fit with learned helplessness?

Again taken from the book “Mistakes were made ( but not by me)” by Carol Tavris and Elliot Aronson Chapter 8, pg 232, they comment on the work by psychologists Harold Stevenson and James Stigler,

“who looked at the 5th grade maths gap between Asian and American school children in the 70’s. The up shot was American children fear making mistakes as they may reflect on their inherent abilities, whereas in Asian culture children are more able to experiment and take risks without such fear. Psychologist Carol Dweck furthered Stevenson and Stiglers work and went on to show that  a self defeating cycle was set up. The ensuing dissonance ( I’m smart and yet I screwed up) led to the American student loosing interest in what they were studying.  Would the cognitive ideas 1..I am smart 2..but I cannot find a solution to the problem also cause dissonance? Would the outcome be the same as for the maths, one of loosing interest in the problem? “

Land reform

A good place to start looking at the history of land ownership and how it has changed over the years may be the Wiki for “three acres and a cow”


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s