FIRST EARTH | Uncompromising Ecological Architecture

Kevin McCabe

I'm Kevin McCabe, I'm a cob builder. I spent about the last 20 years repairing cob buildings, and probably the last 15 building new structures of one sort or another.

Well, originally, I was brought up in a cob house in this part of the world, in East Devon, a 400-year-old cob house, so I knew it was a very pleasant material to live in. And then we had the chance to buy a very old, run-down house, which is quite close to here, about 22 years ago, which was cob. And it just struck me what builders had done to it more recently, what builders tend to do these days, which is stick a cement render over chicken wire, isnít how it survived the last 350-400 years. So I looked into learning about more traditional methods of repair, learned about lime, and applied it to the house. Made quite a few mistakes, but learned a lot, and it kind of progressed from there. Somebody else who wanted a lime plaster heard that I could do it, and basically, I've never really looked back.

Well, that original first cob wall I did on that house, I did a 1-day course with an old guy called Alfie Howard, who is quite well-known in the cob building world in these parts. He was about 70 [years old] then, and his parents built with cob back in the 1920's. And he was the 1st person in this part of the world to begin the cob revival. Cob is very common here. There's 20,000 cob buildings in Devon. So lots of people are aware of it. It's just not many are building with it, I think mainly because of fashion, when bricks became cheap, as much as anything else.

But just from that 1-day course, that was enough. I was a builder anyway. The thing with cob is, there's a lot more to building a house than just the cob. Cob's the easy part, really. But that was enough. I run 1-day courses, and I like to think people go away and do something simple, like a garden wall, and you gradually build on your experience and confidence. I'm still experimenting and stretching the boundaries as often as I can, really.

I use a JCB now, I only recently got it. I've been building cob for 15 years or so, and I only got the JCB 2 years ago. Mind you, I've never looked back! It's the perfect tool, if you've got the site where you've got accessibility for that size of machine. It just takes all the labourious mixing out of it, and you can still be very creative with it, but just get a heck of a lot more done.

In the first building, I wasn't really sure I could do 2 stories in 1 year. No one had done it before, that I was aware of. I think Alfie Howard had done a 2-storey extension, but I think he'd taken 2 years to do it. So I thought I could do it, but I played a little bit safe on the height of the plinth [stone foundation]. I started the plinth up at about nearly a metre high, so that the rest of the wall was probably only about 3 metres. The plinth was about 3 feet high, and add about another 10 feet of cob to get to the eaves. Now, I'd be quite happy to start the cob a lot lower. Basically, because I find cob's such a pleasing medium to work in, I'll do as much as possible in cob, and as little as possible in stone. It's still a good idea to have a bit of a plinth. Generally, I'd get away with about 18 inches now. I think that's enough, with a decent overhang.

For me, the reason to go for that level is efficiency of the space that you're creating. It's the same size roof for 1 storey or 10 stories. You COULD do 10 stories. I would be happy to build a 10 storey building. The thing is, you'd be quite pushed in places. Like over here we've got the point loads of the beam across the fireplace. In fact, that chimney, from the footings that are quite deep here to the cap on the chimney is 48 feet high. But that's all built in about 4 months. The thing with going much higher than that, you'd have trouble doing it in 1 season in this country, because you get a lot of rain. And through the winter, it's impractical to build, unless you've got a roof over you. So, I think anything more than that, probably, realistically, 4 stories, you'd have trouble getting it in 1 season. So then you'd have to just protect it over winter.

And of course, as soon as you introduce structural members, beams and so forth, without a roof on top, they tend to track water in the wall, give you problems. As soon as you've got the main roof trusses up, then you track water in the wall just where you need it to be strong. So you've got to be quite quick once you get to that stage, unless you put a temporary roof over the whole building. Then you really could go probably 10 stories, about the maximum. But that's not very pleasing for me, because that's a lot of stairs to go up. I think probably 3 stories is a comfortable amount of climbing to do.

And it's a very efficient space, the house is quite close to the most efficient shape from a heating point of you would be a sphere, because it's the least surface area for volume to lose the heat out of. I think with the sort of things I'm doing, you're getting close to that. I haven't done an exact round house, because actually, it's quite a difficult shape to make pleasing, usable rooms out of. And also, I think every site deserves its own design, really, I haven't got a pattern ideal house in my head. There's stuff I really like, like big central fireplace which holds heat, and I like that running right up through the centre, towards the centre of the building, not necessarily right in the centre. But every site dictates, whether it be views, or access, how you might design the shape. But the reason I want is, principally, to make the most out of the space available.

This whole structure has been designed by an engineer, or at least, I might have designed it, but he's checked it, or he's designed all the beam sizes, he's designed the roof structure itself. Basically, cob is incredibly strong, compressively. In terms of, say, a concrete block, it's about 1/3 as strong as a standard concrete block. It's at least 1 Newton per square millimetre, if that means anything to you, in terms of compressive strength. Because considering you generally tend to build quite wide walls anyway in a building which needs to be well-insulated, so you can spread the load, any point loads, over a bigger area. It's really not an issue, whether it's structurally up to it. It's easily structurally up to it.

The new house: I've borrowed the money, or put in some of our own money, and borrowed a lot more. Site's very expensive in this part of the world, so you have to make the most of a site to make it economically viable. And you're talking about, that would be in excess of half a million [British] pounds, that's resale. This house here, because we've got all the other out-buildings, is a million-pound house. They're very valuable properties in this part of the world, really. They would be even more valuable if we were a bit nearer London. We're not looking at cheap housing here, it's high-quality end of the market.

I believe in Schumacher: Small Is Beautiful. In a sense, I suppose we've ended up pretty wealthy, because I have worked very hard for a long time, in a way that has made me money. But money hasn't been my raison d'etre at all. I've wanted to make money, not lose it, but my motivation is to do work I'm happy with. And I've been a bit of a workaholic. I think it's easy to look at this now and think that I'm very privileged in some way. Well, obviously, I am, to some extent. It's only because I spend every hour working.

I come at it, I think, because it's just a great material to use, and a more satisfying way to build, and something I can feel happy with to leave behind. But I also think it's quite important to be part of the mainstream and bring it in, because it's taken more seriously by everybody then. That's where I feel what I'm doing has its own merit.