Living Underground

Hobbits, Teletubbies, and attention-seeking magicians have all promoted it in recent times, but this is not a new idea. Our ancestors, having weighed up the options, risked becoming dinner by sharing caves with sabre-toothed beasts in order to gain shelter from the elements and have somewhere they could hang their coats.

Even where no ready-made caves were available, civilizations started getting wise to the advantages of subterranean dwellings. Most notably in the deserts of China and North Africa, where whole communities dug down into the soft rock to create underground rooms grouped around sunken courtyards (think Luke Skywalker’s home on Tatooine). They discovered that they could live more comfortably, out of the harsh winds and extremes of temperature found on the surface, while at the same time keeping as inconspicuous as possible in a featureless terrain.

Though such habitations are still in use up to present times, (even evident in western countries, there are people living in cave dwellings on the outskirts of Granada, Spain) generally, these would be considered as ‘primitive’ and not suitable for modern living. This idea started to change in the 1960/70’s when North Americans were getting increasingly edgy about the escalation of the cold war and the fuel crisis. Experiments and developments in alternative construction techniques occurred, which, while never tested to destruction by those pesky Russians, were able to prove certain, clear advantages in terms of energy conservation.

So, if you are interested in becoming an environmentally conscious, nouveau-troglodyte, the principles are as follows: While air temperature fluctuates on a daily and seasonal basis, the temperature beneath the earth’s surface is relatively stable and should be well above freezing even in winter. The deeper you go, the more this proves to be true, but even at depths of little more than a foot, it starts becoming useful. Also worth noting (at the risk of sounding boring) that, because of its sheer mass, there is also a time delay – when the earth is at its coldest the air has already started to heat up and vice versa. Yes, that’s right, you guessed it, the earth is acting as a ‘temperature moderator’ or ‘thermal flywheel’. Some fancy graphs would probably be useful at this stage to validate these claims but to be honest, I don’t think The Vacuum is that sort of publication.

So, building a house underground or even partially ‘earth sheltered’ can help keep it warm in winter and cool in summer, and therefore offer great reductions on fuel bills against that of your average surface-dweller’s gaff. Because of lack of exposed surfaces or features, there are also savings to be made on maintenance costs (especially if you keep a goat) as well as time saved by not having to consider what color to paint the walls (although you will have to think of a name for the goat).

Living Underground

While in the long term this looks good financially, it’s time to point out one of the disadvantages because initial building costs will almost certainly be higher than a conventional construction, typically by 10-20%. How come? Well, first, you got to dig a great big hole. Bigger than the house itself to allow work to be carried out all around it. Then you got to construct a massive structure to take the weight of all that earth. The most suitable material is reinforced concrete for floor, walls, and roof. This then has to be completely waterproofed on the outer surface. It is critical to get this right at the outset because, believe me, you don’t want to be confronted with the job of trying to locate and repair a leak the next winter. No… really. Insulation is still required in decent quantities if you want to avoid condensation problems on the inside, which I presume you do. Besides, a layer of something is needed to protect the waterproofing from punctures, and this will do the trick nicely. Also, it is a good idea to provide a bit of the old drainage to the base of the walls before you backfill. So, only once the whole structure is covered in earth can you relax, sow your wild oats and let nature take its course. Yes… tucked up in the very womb of Mother Nature, sounds cosy but what about light and ventilation? Remember, this is supposed to be Home Sweet Home, not Tomb Sweet Tomb.

A lot depends on the room layout, which in turn is influenced by location, location, location. In basic terms, a well-drained, south-facing slope would be ideal. That allows the principal rooms to be arranged in a linear fashion, not too deep into the hillside, with plenty of glazing on the sunny side, providing warmth, natural light, fresh air, and views. How about two stories…with a terrace? Now that sounds nice.

If such a site is not available, it can be partially created by building above ground and simply covering the entire structure with earth afterward. This is not cheating. Failing that, a courtyard-type plan could be used, with rooms opening into one or more lightwells, though don’t be expecting dramatic views with this one.

The thermal mass of the concrete structure can turn out to be very useful for passive solar heating, absorbing energy by day, which will be radiated back into the space at night.

Warm, stale air can be extracted through a heat exchanger to pre-heat other stuff, like fresh air or domestic hot water. Long-term energy-saving features like these can soon outweigh the initial cost and energy put into creating the building. Underground living is good for those who like to plan ahead. Which is just as well because when it comes to altering or extending the building, you are fairly stuffed!

If designed properly, an earth-sheltered building has the ability to become almost invisible in the landscape. On the one hand, this makes it an ideal solution for sensitive rural locations. On the other hand, it is equally likely that planners in this part of the world will be gripped by fear when confronted with something unfamiliar. And on the other hand (I’ve got three hands), how do you find your house in the dark, especially perhaps after a wee drink? Imagine getting the wrong front door and waking up next to a badger? Such are the perils to bear in mind.

So, if you feel the urge to settle down and dig in, like the idea of a safe, cosy home with wildlife grazing/fighting/mating on your roof, and don’t mind children pointing and shouting ‘look at the funny mole-man mummy’, then underground living may be for you.