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Cob Homes. [Earth House's]

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Cob Homes have been around for Centuries in the UK.

Currently it is estimated that one half of the world's population – approximately three billion people on six continents – lives or works in buildings constructed of earth" Ronald Rael.
]Cob can be built on a shoestring and livable houses have been built for under £1000[/b]
The word cob comes from an Old English root meaning "a lump or rounded mass". It's a traditional building technique using hand formed lumps of earth mixed with sand and straw. Cob is easy to learn and inexpensive to build. It dries to a hardness similar to lean concrete and is used like adobe to create self supporting, load bearing walls. Cob has been used for centuries throughout Western Europe, even in rainy and windy climates, as far north as the latitude of Alaska.
What does a cob cottage cost?

Cob is one of the cheapest building materials imaginable. Often the soil removed during site work is enough to build the walls. The owner-builder can supply the labor, inviting friends to join in the excitement of hand sculpting a house. With inventiveness and forethought, the costs of other components (doors, windows, roof, floors, etc.) can be extensively reduced.

The Cob Cottage Company works primarily with recycled materials and handwork lumber. Using local materials such as poles, bamboo, stone, and cedar shakes, our second cottage was completed for $500, and has been lanto's and Linda's home for 3 years.

Ianto and Linda's Cob Home:

4099000487_a610ea3409.jpg

4091151261_1f9577891d.jpg

4091931490_5dd3678dbc.jpg

Does anyone have any experience of trying to gain planning permission for a Cob House?

Or a rough estimate as to cost?

There are courses you can attend, where they show you how to self build Cob Homes. Anyone been on one?

Is there any way, groups of us HPC'ers could get together in different areas, and help build each others homes?

[We'll do mine first :D] I wonder what kind of grants we could get?

Could communities get together in mutual self interest and cut out the house builders, and estate agents?

Or is it just too good to be true?

Does cob building require an expert?

Absolutely not! Once the basics are understood, cob building is amazingly simple. In a week long workshop you can learn how to select materials, prepare a mix, and build a wall. We can teach you everything you need to build your cob cottage: site selection, foundations, windows and doors, attachment of wood and other materials, detail work and finishing. Many course graduates with no previous building experience leave our workshops feeling confident and enthusiastic about building their own cob cottage.

Records show that cob houses were being built in England as long ago as the thirteenth century. Very old cob houses built without the use of bricks or wooden supports are still being lived in in many parts of England and Wales, but especially in the West Country. Cob consists of mud and straw, and it's one of the oldest forms of building material in the world. Though it was a popular choice for mediaeval farm labourers it wasn't just the impoverished who lived in cob houses: examples of cob manor houses are still standing today including one at Hayes Barton, which was the birthplace and much-loved childhood home of Sir Walter Raleigh.

Although cob building went out of favour in the late nineteenth and early twentieth centuries its attractions are again being recognised.

Edited by Dan1

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The Traditional Building Technique

The traditional material for English cob was soil (clay-based) mixed with water and straw, sometimes with crushed flint or sand added. People shovelled or stamped the mixture together, after which a cob fork was used to ladle it onto a stone foundation, before workmen on the walls trod it into place. It was quite possible to lay a course or "lift" of cob between 150mm and 900mm high (but usually averaging 450 mm) in a single day. After it had dried - which could take up to a fortnight - the next lift would be added. The walls would be trimmed to plumb and straight as they rose and made between 500mm and 900mm thick. The builders would either leave openings for windows and doors, adding stone lintels as they went, or carve them out later. It was a community effort, with men working one day a week to build a house in a season.

Modern Construction

Unsurprisingly, perhaps, modern cob techniques remain much the same. The biggest development has been Oregon cob, where people mix the material into mud loaves, then add them individually to the wall before treading them in. This method means houses can have walls that are stronger and thinner (generally 300-500mm thick on load bearing walls, as little as 100mm on others).

Materials

You can make your own cob, even if you don't live in an area with a heavy clay content in the soil. Just mix soil, clay, sand and straw to a consistency like dough, and start your wall.

Construction

You're going to find the process very labour-intensive. The good part is that it's very environmentally-friendly - all done by hand. In fact, you can have the walls take on any shape you wish, something you'll find in many adventurous modern cob homes. The only thing you really have to remember is to lay the material in courses, and let each one dry thoroughly before laying the next, and make sure they taper slightly as they rise. You can embed windows and doors as you build, or simply cut holes later.Cob is excellent for load bearing, meaning you can easily make a two-storey house, and it has very good insulation for both heat and noise. During the day it absorbs heat outside, so it's cool inside, but at night radiates that heat into the interior.

Foundation

You need to start with a foundation that's wider than your wall will be - 300mm wider is recommended - and deep enough for the load. Usually you'll build a cob house on a stone plinth or a concrete base, raised off the ground about 600 mm - for obvious reasons it can't come in contact with the ground. There are any number of foundation options you can use, like a rubble trench, earth bags, or even rammed tyres.You'll also need a good roof overhang to protect the cob, at least 200mm. If you find any vertical cracks, use cob or even clay tiles to fix it before moisture can penetrate.

Rendering and Moisture

Cob has to "breathe" - to dry out naturally after becoming wet. It used to be that the exterior walls were either left bare or lime rendered (which is expensive these days). Excessive moisture can give you a problem, but you also need a balance, as the material needs some moisture (3-5% is considered good - much higher than that and you might have rising damp).

U-Value

Cob generally exceeds the minimum u-values for a house. It rises higher if you put plaster inside and render the exterior. You can also use stone facing on the base wall as insulation.

Edited by Dan1

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These are Photos of Cob Homes which cost from just £568.00 to just £32k.

They are in Canada

It just shows what could be possible and achievable in the UK with a little help from the Government

Edited by Dan1

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Looks great, but I bet at the end of the road there is a government bulldozer waiting to flatten your home. Can't have anyone prospering outside the system.

Look at the Video@ 6:33.

What a truly magnificent home. And for under £32k.

The Government better bring house prices back down sharpish, or ban emigration.

Edited by Dan1

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Similar to cob building, I've always fancied a straw bale house. Cheap material, really good insulation, no fire hazard as it's too tightly packed to burn (not enough oxygen).

The benefit of straw bale over cob is that you can put the walls up in a few days rather than a few months, and shape them with a chainsaw.

The disadvantage is that you really need to build a timber frame as the main structure, the bales are just infill. but even so, the bales are a lot cheaper than bricks and mortar and easier for a newbie to work with.

Not sure what the mortgage situation is like for cob or for straw bale builds? I guess you might need to fund it in cash. Although certainly in the case of straw, the house is as robust as any "traditionally" built house, so I can't see any reason why they should be treated differently for mortgage purposes.

The best one I ever saw was on one of the grand designs programmes. Beautiful when it was finished.

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Similar to cob building, I've always fancied a straw bale house. Cheap material, really good insulation, no fire hazard as it's too tightly packed to burn (not enough oxygen).

The benefit of straw bale over cob is that you can put the walls up in a few days rather than a few months, and shape them with a chainsaw.

The disadvantage is that you really need to build a timber frame as the main structure, the bales are just infill. but even so, the bales are a lot cheaper than bricks and mortar and easier for a newbie to work with.

Not sure what the mortgage situation is like for cob or for straw bale builds? I guess you might need to fund it in cash. Although certainly in the case of straw, the house is as robust as any "traditionally" built house, so I can't see any reason why they should be treated differently for mortgage purposes.

The best one I ever saw was on one of the grand designs programmes. Beautiful when it was finished.

Ben Laws House. [ I agree. A Stunning Home. And Kevin McClouds all time favorite Grand Design]

bensplace.jpg

Edited by Dan1

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Cob Homes have been around for Centuries in the UK.

Ianto and Linda's Cob Home:

4099000487_a610ea3409.jpg

4091151261_1f9577891d.jpg

4091931490_5dd3678dbc.jpg

Does anyone have any experience of trying to gain planning permission for a Cob House?

Or a rough estimate as to cost?

There are courses you can attend, where they show you how to self build Cob Homes. Anyone been on one?

Is there any way, groups of us HPC'ers could get together in different areas, and help build each others homes?

[We'll do mine first :D] I wonder what kind of grants we could get?

Could communities get together in mutual self interest and cut out the house builders, and estate agents?

Or is it just too good to be true?

Great, great, I love this kind of stuff, if there was anyone in my area who wanted to build one I would give up time for free.

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Great, great, I love this kind of stuff, if there was anyone in my area who wanted to build one I would give up time for free.

Me too Scott.

I'd like to find out more. If the Coalition de-reg planning, would it be possible to build a Cob home?Community projects etc?

I'm sure someone on here will know more, and come along and enlighten us.

Edited by Dan1

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Look at the Video@ 6:33.

What a truly magnificent home. And for under £31k.

The Government better bring house prices back down sharpish, or ban emigration.

Emigrate while you can. I, or more accurately my wife, have a house in Thailand on about 4 acres of land. Cost next to nothing to put up and no dickhead civil servant had any say on what it looked like or anything about energy efficiency or safety or other bullsh**e.

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Ben Laws House. [ I agree. A Stunning Home. And Kevin McClouds all time favorite Grand Design]

bensplace.jpg

That's the one. I still tell anyone who will listen about that house and about that construction method! (They usually yawn and change the subject!)

If I recall correctly, he was a charcoal burner/woodsman wasn't he and as such had a special dispensation to be allowed to build in the wood, with the condition that he could not sell the house on if he ever decided to move away (why would you!?)

I would love to get together with some like minded people and spend a year building a half dozen unique houses like this on a decent sized piece of land, everyone pitching in. Would need to be somewhere suitably rural and beautiful though. Do you think that the new tory planning proposals make it more likely to happen or are they going to be skewed so as to make sure the only people that can build in good locations are the mega slave box building firms?

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That's the one. I still tell anyone who will listen about that house and about that construction method! (They usually yawn and change the subject!)

If I recall correctly, he was a charcoal burner/woodsman wasn't he and as such had a special dispensation to be allowed to build in the wood, with the condition that he could not sell the house on if he ever decided to move away (why would you!?)

I would love to get together with some like minded people and spend a year building a half dozen unique houses like this on a decent sized piece of land, everyone pitching in. Would need to be somewhere suitably rural and beautiful though. Do you think that the new tory planning proposals make it more likely to happen or are they going to be skewed so as to make sure the only people that can build in good locations are the mega slave box building firms?

Yes. He was a Woodsman. Green Woodworker. And he could pass his house to his son. But not sell it. I think he had been working in the woodland he owned for many years though, before he was allowed to build. Otherwise I would have bought a bit of woodland, some charcoal braziers, and claimed it was a business by now. :)

http://www.ben-law.co.uk/

We could all chip in and help build each others houses.

[it wouldnt neccesarily even have to be on the same plot of land.] We could form conglomerates. Even if we were in different counties. So long as we were willing to travel...[Thats what Ben Law did. He had people from all over helping him]..Although maybe there would be some sort of monetary benefit/grants/tax breaks if it was the same plot. The NIMBYS would be out in force, at the thought of large mud huts being built up the road.....

[.In a hole in the ground there lived a ......HPC'er!] lol

....The dream of affordadable housing.....

I keep hearing things about the coalition deregulating planning. Will have to wait and see.

Edited by Dan1

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http://www.ben-law.co.uk/

We could all chip in and help build each others houses.

[it wouldnt neccesarily even have to be on the same plot of land.] We could form conglomerates. Even if we were in different counties. So long as we were willing to travel...

Thanks for the link, according to the local library website they have a copy of his book currently on the shelf, so I may go and borrow that tomorrow!

Whereabouts in the country do you live, out of interest. We (Me, Wife and Young Son) are based in Chester but have family in West Yorkshire and Northamptonshire and since I quit my job to do freelance illustration, we have no ties to anywhere in particular. Was thinking of having a few short breaks in various parts of the country as I haven't seen a lot of it to be honest beyond the places that friends or relatives live. Want to find somewhere lovely to build one of these cob or straw houses!

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Look at the Video@ 6:33.

What a truly magnificent home. And for under £32k.

The Government better bring house prices back down sharpish, or ban emigration.

Probably not that much more to build one using the current techniques here... finding somewhere to put it on the other hand...

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U-Value

Cob generally exceeds the minimum u-values for a house. It rises higher if you put plaster inside and render the exterior. You can also use stone facing on the base wall as insulation.

You'd want a lot more than minimum and thicker cob walls improves the value or rating.

Like other earthen wall systems, cob does not have a very high insulation value per thickness (less than R=0.5 per inch.). One way to get a higher R-value is to build a very thick wall. The traditional 3-foot-thick cob walls in Devon may have the equivalent of R=15 or so. The problem is that in a very cold climate such as yours, all that mass will be constantly losing heat to the outside, especially on the north side of the building and other parts that never receive direct sun in the winter.

Loads more here including cob and straw hybrid.

Similar to cob building, I've always fancied a straw bale house. Cheap material, really good insulation, no fire hazard as it's too tightly packed to burn (not enough oxygen).

The benefit of straw bale over cob is that you can put the walls up in a few days rather than a few months, and shape them with a chainsaw.

Agree with you because cob walls, each layer needs good time to properly dry out. Learning from others mistakes I would source straw bales with a very low grain content. That computer engineer in Scotland who built a straw bale house for £4,000. It didn't all go smoothly. His older website documents all their hard work building the house during the Spring to Autumn before covering it over for Winter. Come Spring as they went to complete it, they found they had to knock all the walls down and begin all over again. The tarps they'd used were not good enough quality leading to water penetration and the bales they'd used had high grain content which attracted hungry rats. See the 'Disaster' section.

In addition, our farmer had trouble harvesting his outs that year, resulting in an unusually high grain content in the bales. The entire pile of loose straw visible in the corner was created by rats who burrowed through the loose straw in these badly made front corners in search of the grain. Other more compact areas of the walls were left untouched.

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You'll have more chance of getting planning permission for a city centre block of flats that makes Wormwood Scrubs look like One Hyde Park

What's all this about localism though? As a member of our parish council's planning commitee I'll agree to almost anything! It's just the district council that's the problem but maybe this will change.

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Lovely looking houses. I have no idea why we have this obsession with bricks and concrete, cob is an excellent and cheap building material, as is clapboard.

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Me too Scott.

I'd like to find out more. If the Coalition de-reg planning, would it be possible to build a Cob home?Community projects etc?

I'm sure someone on here will know more, and come along and enlighten us.

I rented/lived in a huge bungalow which was a ex-farmers house built in the 1930's with 8" cob walls.

It was extremely cold and required loads of heating.

The outside walls had been 'weatherproofed' by the dumb landlord with paint that didn't allow moisture to escape and even with open fireplace/chimney (which sucked all warm air out of the place when Siberian blasts blew) caused damp/black mould problems coz the walls couldn't breathe properly anymore.

Trying to hang anything on the walls was a nightmare as you can imagine - coz they just crumbled.

You def. need a double cavity wall to insulate the place better or perhaps that plasterboard with 4" insulation on one side of it for each room.

It was quite weird looking out of the huge lounge window, down the hill or sitting down to dinner in dining room to see a massive combine or tractor approaching as it shook the place.

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How durable are these things? What kind of maintenance do they need?

Well it was still sturdy, sitting exposed on a hill since the 30's and survived the hurricane with winds hitting sustained 120mph in Norfolk!

Zilch in the 6 yrs I rented it. Never saw the landlord except occasionally when out shooting.

Landlord let me knock down the old 30's larder cupboard in the kitchen and 'retrofit' a previously 'fitted' kitchen we had been given by friends when they had a new one installed. Made room for a breakfast bar. The walls in the kitchen had a double wire mesh tacked on them and concrete? skim so you could hang the wall cabinets.

And I installed an elec shower above the bath. Drilling the hole for extractor fan was fun - had to work from inside and outside hoping the holes would meet.

Edited by erranta

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100k box/garage with a toilet and a sink VI crowd not going to go for this, how else will these important people make a living.

Gordonomics (soon to return) would suggest that the house must saddle you with debt for the rest of your life therefore a £32,000 house is just not on the cards unless hell freezes over. Always remember - got to get a liebour loan to own a home.

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This looks interesting:

Its a building Society whom fund and also offer workshops on Ecological Self Build's [And conversions]

http://www.ecology.c.../gallery.htm#hq

I will call them next week, and ask them about Cob Buildings/cost of building materials/Cost of Land /Planning Permission/Co-operative community building projects/Grants etc.

And post their response.

Edited by Dan1

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