Earth dwellings have been in use for as long as people have been
building shelters, and are still in use today. Native Americans
once created earth lodges that were mostly underground, circular
in construction and will dome roofs.
Ancient as well as modern earth lodges use soil as an integral
component in order to create a thermally-effective structure.
The dwelling may be earth-bonded, in which soil is used to insulate
one or more of the building's elevations.
Alternatively, the structure
could be earth-covered, in which earth is used
to insulate the roof of the building, or the building could be
built into a hill, with only one side exposed in order to provide
light and passive or active solar heat. Sometimes the entire dwelling
is built below-grade, with light and ventilation provided by means
of a central atrium.
There are several benefits to earth lodges. The structure is
protected from the elements, offers privacy, makes effective use
of available land and is naturally sound-proofed. It is very energy-efficient
because the earth naturally absorbs heat and then retains it.
Changes in temperature occur slowly, so the structure is easy
to keep warm in the winter and remains cool in the hotter months.
One problem with earth-sheltered housing is that water seepage
can occur. To prevent this, vents can be placed in the roof or
along the walls. Environmentalists typically appreciate the low
energy requirements of earth dwellings, but find the fact that
many of them are made with plastic and other non-biodegradable
materials somewhat problematic.
Earth Lodge Construction
Site planning is very important
to the overall design of an earth lodge. On relatively
flat land, a house that is fully recessed is a very effective
design. Where the land slopes, the dwelling can be set directly
into the hill. The "window wall" is generally located
on the southern exposure in order to fully maximize the passive
solar capabilities of the design.
Where temperatures are extreme, the earth's natural insulating
capabilities can provide comfort. Wind is a factor to be considered.
Typically there are few windows in an earth dwelling, so it is
important to know the intensity and direction of the wind in order
to take advantage of natural ventilation. In areas where winter
winds are extreme, sufficient vegetation should be left around
the dwelling in order to provide a natural wind-break.
It is also essential to
consider the type of soil when planning the dwelling.
The best type of soil for drainage is a mix of gravel and sand.
If the soil has a high clay content, drainage can be problematic.
If the area is prone to frost heave, the foundation should be
situated below the frost line. Waterproofing is essential, generally
consisting of a layer of liquid asphalt. Additionally, foam or
insulation board should be placed on the outside of the waterproof
When designing an atrium, it is important to make sure that the
earth slopes away from the building on each side. A drain pipe
along the edge of the roof can also divert water from the structure.
The most common material used in constructing an earth lodge
is reinforced concrete. Wood is not suitable because of its tendency
to rot when exposed to earth. The problem with reinforced concrete
is that it is not environmentally sustainable, but the concrete
industry is developing more earth-friendly products in response
to the public's increased demand for eco-friendly construction.
Modern Luxury Earth Lodge Interior
The earth dwelling differs
from conventional housing in that the insulation
is applied to the exterior of the house rather than the interior.
This is to enable the shelter to maintain its appropriate temperature.
Polystyrene sheets or spray foam can be used. The foam works
exceptionally well for structures that are unconventional, such
as rounded dwellings. In some areas, insulation will not be required,
but if the temperatures range from very hot to very cold, insulation
will be essential.
As we become more and more concerned with environmental sustainability,
it is not unreasonable to think that this time-honored method
of construction may enjoy a significant revival.