The wonders of living underground

Page 1: Types of subterranean home
Page 2: Questions and misconceptions
Page 3: Buying an underground dwelling

Anna Heywood - Writer

Buying an underground dwelling

Availability

With relatively few underground dwellings in existence, finding a suitable house in your area might be difficult. Also consider that most earth-sheltered homes are built by the owner, who is less likely to move than a conventional home owner. There are no specialist estate agents for underground dwellings it's simply too small a market. However, Green Moves, the UK's only dedicated eco property selling website, might be a good place to start. Also let your local estate agents know that you are looking for an underground home, so they are aware of your interest if one should come onto the market.

Costs

The Hockerton Housing Project, completed in 1998, is a development of five single storey earth-sheltered dwellings. Each house is 6 m deep with a 19 m south-facing conservatory running the full width of each dwelling. The cost of the homes was approximately 90,000 (485/square metre).

At the other end of the affordability scale is The Burrow, an earth-sheltered home in Harbledown near Canterbury, which went on sale in May 2007 for 2 million. With five bedrooms, indoor swimming pool and sauna, this is a luxury property with a price tag to rival any above-ground equivalent.

Building your own burrow

You have to be committed to see any self-build through, perhaps more so with underground dwellings as they are still a rarity and professional expertise is almost definitely required. For an idea of what you might be letting yourself in for, check out this Grand Designs project to build an underground house in a disused quarry.

Finding a site

To a certain extent the design of an underground home is determined by the conditions of the site. Soil type, topography, precipitation, ground water levels, load-bearing properties, and slope stability all need to be carefully considered. Construction materials need to be waterproof, durable and strong enough to withstand underground pressure (concrete is frequently used). Water is a particular consideration in underground building, and special drainage techniques may need to be implemented around the site, particularly along the roof areas. Climate and topography, soil and groundwater level are all important considerations when picking a site. Ideally, underground dwellings should be sited:

  • to take climate and micro-climate into account. If the area experiences harsh, long winters a south-facing slope is best, as south-facing windows allow direct solar heating and plenty of natural light. Less severe winters and hot summers would require a north-facing slope, to keep the building cool.
  • with topography in mind. The steeper the slope, the less excavation is required. Contrary to conventional house building wisdom, a flat site is actually the most demanding as it requires extensive excavation.
  • above the water table in a location where the water will naturally drain away from the building. This avoids undue water pressure against underground walls.

Planning permission

Like any other major structure, an earth-sheltered or fully subterranean dwelling requires planning permission. In addition, they are required to conform to building regulations, which set standards for the design and construction of buildings to ensure the safety and health for people living in them and the vicinity. Special considerations may be necessary for underground dwellings but in principle planning authorities make no distinction between an application for an underground or conventional development. Employing a planning consultant may help you put together a good case, and improve your chances of obtaining permission. Contact your local planning officer, or visit the Government's Planning Portal for further information.

Expertise

As with any self-build project you need to do your homework. Read up on sustainable building before you even begin the design stage. Get advice from organisations like The Sustainable Building Association and the British Earth Sheltering Association. This online Encyclopaedia of Alternative Energy and Sustainable Living also has some very useful information about earth-sheltered home construction. It is advisable to use an architect, builder and project manager (if you use one) who is familiar with underground dwellings, or at least with experience in the field of green construction.

Finance

It can be more difficult to secure a mortgage for an underground dwelling, so it's worth finding out what your options are at an early stage. Established in 1981 the Ecology Building Society is one of the fastest growing building societies in the country. This West Yorkshire organisation specialises in finance for green homes and sustainable building projects.

Financial assistance may also be available from The Sustainable Development Fund if you live in a National Park. It's a grant scheme funded by DEFRA, which aims to promote sustainable living. You can also contact the Energy Savings Trust who can provide details of grants and awards you may be eligible for.

More information about going underground

As well as the organisations mentioned above, there are several existing underground houses or spaces which you may like to visit, virtually at least, by checking out these websites: The Underground House, Cumbria, Feldon Forest Farm, Warwickshire, Hockerton Housing Project, Nottinghamshire, Caer Llan, Monmouthshire.

Finally, the website of Malcolm Wells is a veritable treasure trove of resources about underground living. Considered by many to be, literally, the architect of the modern earth-sheltered home, his books and designs are inspirational. Essential reading for anyone considering underground living.

 
 


Property pros