Masonry Magazine April 1993 Page. 38
Solar Earthen-House Takes Shape in Vermont
Offbeat architectural form combines a very old building method with a variety of sophisticated modern day technologies.
A culmination of the dreams of a lifetime, a solar earthen-house is taking shape in Vermont. This offbeat architectural form combines a very old building method-related to adobe and masonry-with a variety of sophisticated modern day technologies. Utilizing extruded polystyrene insulation, acrylic liquid, elastomeric paint, E-glass-plus Portland cement to stabilize the mud. The solar heated dwelling is designed to ride out severe northern winters, and could be built at minimum cost by relatively inexperienced workmen.
This experimental earth construction project in central Vermont is intended to bring current technology and a new sense of design to a very old method of building. The earthen-house, a staple of primitive construction in warm climates, is finally being adapted for cold weather use.
At a more basic level, the solar earth house sets a different standard for personal scale domestic architecture. Radiating a sense of shelter, its organic forms and spaces satisfy a basic emotional need.
Basic structure of the earthen-house is the dome, and both dome and arch forms are reverse catenaries. Essentially in compression, the domes need no expansion joints and no rod reinforcing, though a plastic mesh is used in certain areas. Except for the extruded polystyrene insulating board core, which establishes the form and receives the cement stabilized mud, no form work is required for the domes, even though the largest is some thirty feet in diameter and twenty feet high.
The earthen-house is situated on a 66 acre tract in the town of Marshfield, Vermont. In intensely rural central Vermont the woods are still woods and the streams are still streams and there aren't many houses. BOCA is far away, an urban requirement. Future large-scale adoption of the earthen-house concept would mean some rethinking of the BOCA code but for the moment there are no codes to work to and, in this case, there's only one person to satisfy: the architect is his own builder and his own client too.
Hand-crafting a mud house is almost like the work of a potter. Each handful of mud is bonded to the next, until the foam core, the mud and the set-in solar glass become one handsome, monolithic structure, the ideal vehicle for passive solar heating.
The effectiveness and continuity of the insulation, its air-tightness and the heat storage potential of the mass of the earth structure make an ideal solar ambiance. While it is expected that the house will be almost totally solar heated, two open fireplaces, especially designed for heat efficiency, are planned. There will also be a small catalytic wood burning stove with hot water capability to assist the solar hot water and heating as may be needed for Vermont winter, where the themometer can stick at minus-twenty for weeks at a time.
What is the best way of using mud? Since a cold-weather mud house had never been attempted before, a good deal of experimentation, and a few false starts, were involved. Developing the technique involved complex assessments of the interaction of sophisticated technologies, but the structure itself is built without need for engineering calculations. After materials have been assembled, most of the actual construction can be done by one relatively inexperienced person.
The continuous core of the structure is made of pink Foamular extruded polystyrene insulating board. Next to the earth itself, it's the most essential building material, providing insulation, air tightness, a vapor barrier, and the only form work used in
CONTINUOUS CORE OF THE EARTHEN-HOUSE are the extruded polystyrene insulating boards. They're lightweight, easily cut and handled by one man. Water resistant and rugged, they're rigid enough to support the wet earth mixture, yet yielding enough to flex with the finished structure.