Earth shelter

An earth shelter, is a term to describe a building that is effectively protected by earth, in that its external envelope is in contact with a significant amount of soil or natural substrate. This term usually refers to a building that benefits the ground coupling effect or earth coupling, in that the soil or earth surrounding the building impacts the thermal performance of the building itself.

Such earth-sheltered buildings care either earth-covered, earth bermed (or earth-bunded), or subterranean., so that they benefit from the constant ground temperature of the earth to differing degrees. These types of buildings differ from other earth coupled buildings that do so through earth to air heat exchangers, ground source heat pumps and such like because they connect directly to the earths thermal performance rather than indirectly.

Earth shelters or earth sheltered buildings, are often referred to as earth bermed buildings, which is a design approach that connects a building more significantly to the ground and landscape around it. Depending on the detail design approach, the building will, to differing degrees benefit from an earth coupling effect, where by the thermal mass, insulative and protective qualities of the surrounding earth benefit the thermal performance of the building.

Below around three metres earth tends to have a relatively constant ground temperature, which means in the summer it is cooler than the outside temperature and in winter it is warmer than the outside temperature, this effect lessens gradually as the depth decreases. An earth coupled building does not insulate between the internal space and the earth and as such benefits from the decreased fluctuation of the earths temperature, it will however have insulation and normally high internal mass or glazing on any walls exposed externally.

One well know example of an earth shelter which makes use of waste materials, in particular car tyres, are referred to as earth ships. The term Earthship, was coined by the self-proclaimed biotect architectural designer and environmentalist Mike Reynolds. The term derives from homes being in and of the earth, similarly to earth shelters though defines itself as being constructed in a particular way using primarily waste materials, in particular car tyres with rammed earth and waste glass bottles. The Earthship movement started in the US but is now global with many Earthships having been built throughout the globe, In the UK there is also an example of an Earthship in Brighton.

Another well known UK example of an earth bermed housing scheme is the Hockerton Housing Project, which is a linear cluster of five self-sufficient houses built in Nottinghamshire in 1997 by Brenda Vale. Theses houses are earth coupled and as such require zero to minimal heating and have lower-than-normal energy consumption, which is supplied by onsite renewable energy generation from two 6 kW turbines and 7.6 kW solar panels.

[edit] Related articles on Designing Buildings

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• Basement waterproofing.
• Bund.
• CarTube.
• Catacomb.
• Excavation.
• Earth to air heat exchangers.
• Earthships in Europe.
• Geothermal energy.
• Geothermal pile foundations.
• Ground energy options
• Ground preconditioning of supply air.
• Ground source heat pumps.
• Gabion.
• Global undergrounds - exploring cities within.
• Oubliette.
• Planning (Subterranean Development) Bill.
• Substructure.
• Stad Ship Tunnel.
• The Lowline.
• Thermal labyrinths.
• Tunnels.
• Underground.