House: History

How did I come to my current thinking on the design of an off-grid house?

Beginning

I first started thinking about alternative methods of house construction in the 1970s under the influence of a number of sources: in the real world the OPEC oil crises, the Club of Rome reports and so on and, less real, science fiction, particularly by Arthur C. Clark and, to a lesser extent, by Issac Asimov, depicting societies in which telecommunications were in widespread use, replacing much travel, so that people could live wherever they wanted to.

Through-out my career I've been interested in furthering the use of telecomms for these sorts of reasons: at college my central interests were certain aspects of programming language design but a strong subsidiary interest was in networking and when I was at Hewlett-Packard I worked on a number of e-mail projects and a couple of experimental systems designed specifically for multimedia distributed workgroup cooperation.

In the late 1970s or early 1980s I was particularly intrigued by the idea of underground houses. The first such real house I came across was Arthur Quarmby's Underhill on the edge of the Peak District National Park near Huddersfield which was described and shown in an Observer (I think it was) article. Things that appealed about an underground house included:

Though I've now lived on this planet for 52 years I still haven't really adapted to its 24 hour day-night cycle and often get pretty depressed and/or bad tempered when I haven't slept when I need to. Underground housing seems to have the attraction of allowing one to sleep and wake in accordance with one's own body clock without being restricted by natural or artificial temperature swings in the building.

Later

This was all just a vague idea until round about 2000 when I started to get a bit more seriously interested and started looking around on the Web for ideas. I found there's a huge amount going on in a very quiet and decentralized way (good!). What I did find, though, was that there were a lot of different little sub-cultures with good ideas and useful experience but each seemed to be as narrow-mindedly set on their own ways of doing things as the main-stream building industry.

Therefore, I continued to read around both on-line and in books trying to pick up ideas and understand principles but not get too attached to individual "systems" of building. Nevertheless, I did tend to have favourites at various times. The rough sequence was:

Umbrella Houses and PAHS

The first realization was that building underground gives good thermal mass but is actually surprisingly poor from the point of view of insulation, particularly if there is any water in the soil. Water flowing through the soil is even worse as it rapidly carries heat away.

Therefore I took a lot of interest in the ideas of John Hait for umbrella houses and Passive Annual Heat Storage systems (PAHS or PACCS). These are houses which are buried with a waterproof membrane ("umbrella") extending out through the ground to a distance of about 6 metres to keep the soil dry. They store heat in the soil in the summer and release it back into the house in the winter.

Earth-bermed and Earthships

However, as I read more I came to realise that the full umbrella house concept was not required (e.g., this house). In particular, Don Stephens' Annualized Geo-Solar designs use the soil beneath a more-conventional house to store heat from the summer for use in the winter.

An example of this general type of house which caught my attention early on was this Cumbrian underground house shown on the Channel 4 Grand Designs series.

I've visited a couple of such buildings: the Hockerton Housing Project and, twice: once in the middle of the build and once towards the end, the Brighton Earthship. Two I've followed more virtually are Es-Cargo in Queubec and Oscar and Lisa's Earthship in Valencia.

In general, I still think that Earthships and, more generally, earth bermed houses are good idea. However, it seems to me that there is either a lot of labour involved in such construction or some fairly critical use of heavy equipment. Pounding tyres for a proper Earthship does not appeal.

Part of the appeal of an earth-bermed building is that the earth acts as a thermal mass to even out the temperatures. However, earth is not a good insulator, particularly if there is a possibility of water running through it, so to get the full effect insulation has to be placed outboard of at least some of the earth but still be waterproofed.

Additionally, earth berming requires earth. At this time I was beginning to seriously think about sites and was considering either the south-west of England or parts of Wales. In either case the rock would be likely to start not many centimetres below ground level.

As a result I went off the idea of burying a house for a one-off build by somebody who has little experience of this sort of thing.

Straw Bale

Straw bale quite appealed for a number of reasons and I seriously considered it. As with earth berming I still think it's a good idea in the right circumstances but I'm not sure it's for me.

Though putting the bales up is a fairly quick job it's still really one which calls for a team. Once they're up it's pretty important to get them protected from the weather as quickly as possible and there's quite a lot of labour before the final covering will be in place.

Also, straw bales deal nicely with the walls but they don't help much with the roof. Particularly for a single-story building the roof is likely to require the most insulation both because of its relatively large area and because of its exposure to the cold sky.

Shipping Containers

At about the same time as I was considering straw bale I also thought that building using ISO shipping containers offered some major advantages. In particular, you have a waterproof shell to work with the moment that the materials are delivered to site.

I took a couple of trips down to Trinity Buoy Wharf and had a good look at some containers in the process of being converted which I found pretty encouraging.

However, there are two difficulties with containers. First, they need to be insulated. If you do that on the inside then extreme care is needed to deal with any possible condensation: corten steel being somewhat impermeable. Also, the space left over is not large. Therefore you really need to put the insulation on the outside which then needs something to protect it from the weather which is reasonably self supporting to avoid too much cold bridging, at which point it's difficult to see what the container is really helping with.

Secondly, even with the insulation on the outside, the internal dimensions of containers are a bit awkward. A single container is too narrow for most normal room sizes whereas a double container is only really suitable for the larger rooms. Consequently you finish up chopping the containers around a bit which again seems to miss the point.

An idea I toyed with for a while was taking shipping containers and insulating them on the outside with straw bales covered with a fairly lightweight skin to contain the straw, protect it from rodents, fire, etc., then surround the whole thing with a much larger greenhouse like structure for weather protection.

Current

Influences

Laren Corie

Who?

Themes

Self-build Timber Frame Cellulose Solar-air sunspaces, indirect gain, low thermal mass Water for thermal store

References

ESSN 2005-01 pg 9: Elements of Passive Solar ** 2005-02 pg 10: Instant Sunspaces ** 2005-03 pg 9: It’s Too Cold And Cloudy For Solar ... Not! ** 2005-05 pg 9: Overhangs and Oversights 2005-06 pg 12: Keeping Cool 2005-07 pg 24: Staying Cool 2005-08 pg 11: Insulating Your Old House ** 2005-09 pg 9: Building a Very Simple Solar Water Heater

Laren Corie

Walter Segal

Walter Segal

Segal method