Are you seriously considering living underground? Or maybe you are just intrigued by the idea of a sub-surface home? Either way, this article is for you. We guide you through the various forms of underground dwelling, as well as the benefits and the feasibility of buying or building your own.
Living below ground – a new phenomenon?
Archaeological and historical evidence suggests humans have been living underground for millennia. The earliest human remains come from cave sites, and there is later evidence from around the world of pit-houses, shallow excavations roofed with sticks, mud and thatch, and other semi-subterranean dwellings.
Ethiopia's 13th century monolithic cave churches are an amazing example of rock-hewn, underground spaces, listed by UNESCO as a World Heritage Site. In the Chinese region of Shaanxi, caves burrowed out of the soft, loess soil have been protecting their inhabitants from severe winters and high summer temperatures for thousands of years.
Locals still prefer their cave dwellings to modern, free-standing homes. Similar examples from around the world indicate that underground dwellings are the ideal solution to particular ecological problems and, often, a resource shortage such as a lack of wood or timber which prevents above-ground structures being built.
It seems to have taken modern society a little time to catch on. The potential of underground living was recognised in the West during the oil shortages of the early 1970s. The desire for sustainable building and energy efficiency saw a surge in the number of underground dwellings in the USA and Continental Europe in particular. There are up to 100,000 semi-subterranean or fully underground dwellings in the USA but, right now, Japan seems to be at the forefront of underground innovation.
This overcrowded island has embraced the concept of subterranean living like no other nation. Tokyo's land prices have reached incredible levels – over £4 billion per acre - driving developers underground and giving rise to some ground-breaking, large-scale projects. The Taisei Corporation's self-contained "Alice City" is an underground metropolis, which uses valuable underground real estate to recreate an above-ground office and living space.
The huge cylindrical shaft also incorporates power generation, heating, waste recycling and sewage treatment facilities. Perhaps this is the future of city living? In the meantime, currently subterranean dwellings make up only a tiny fraction of UK housing stock – less than 100 out of the UK's 21 million homes are underground. That's a mere 0.0003%!
Types of subterranean home
In the same way that above-ground houses vary greatly in their construction and appearance, underground dwellings also differ. These are the major types:
These are made by tunnelling or drilling cavities into earth or rock. Essentially the same as a natural cave, constructed caves differ in that they are man-made. Found throughout the world, a famous example is the Australian outback town of Coober Pedy. Most residents in this opal mining town live in caves drilled into the hillside, an effective way to insulate homes from the scorching summer heat. Constructing a cave can be an expensive and dangerous procedure, and is very dependent on suitable geology.
The dwelling is designed as a series of units, made from precast concrete pipes and containers. A pit is then excavated and the prefabricated house lowered into it and covered over with earth. These “cut and cover” dwellings are entirely buried.
Earth Berm Dwellings
A berm is a mound of earth, which offers thermal insulation and protects exterior walls. The house is constructed above ground, with the berms then added on three or four sides, leaving either one wall or simply the roof free for access and light. This type of house is classed as semi-subterranean, and is also referred to as an Earth Sheltered Dwelling.
The same principle as the berm dwelling, except that the house is built into the side of an existing hill. The roof is therefore covered with earth, but the front of the home is left open to the outside. This is one of the most popular forms of underground dwelling and, because of the large amount of natural light and the fact that the house entrance is at ground level, offers something of a transition between conventional, above-ground, and underground living for those who don't want to embrace a totally subterranean lifestyle.
Atrium or Courtyard Homes
These dwellings are built below ground, but have access to outside light via a central courtyard. The whole footprint of the house is excavated before the walls are built around the sunken courtyard or garden. Material excavated is often used in the construction of the dwelling for financial and energy efficiency reasons.