DESCRIPTION du projet et  Intentions de l'équipe A .
thermoshelter

MODEL PROPOSAL FOR TRANSITIONAL HOUSING OF THE KOSOVARS

STRUCTURE

THERMOSHELTER 1 was constructed in 1998 in Atlin, BC, near the Canada/Alaska border. Its tensioning roof is 4 foot strips of 24 gauge galvanized sheet metal attached to a concrete foundation, creating a 3-4 psi prestress in the rigid cellular insulation, in this case 22 inch thick EPS shaped blocks.

The circular arch is made of 50 identical blocks of EPS, weighing approximately 70 lbs. each. The vault is 40 feet long with an interior radius of 11 feet. The sheet metal is screwed to a steel angle which is bolted to the foundation. A total of 3 inches was forced out of the length of the foam arch. The resulting composite structure meets rigorous, local building codes for wind and snow loads.

 

 

In ThemoShelter 2, completed at the same site, the modified parabolic arch has been engineered considering the structural benefit of an interior acrylic plaster finish, which doubles its strength and quadruples its stiffness.

Particular attention has been paid to issues of long term creep, choosing a conservative low-level pressure. Temperature induced changes of compression have also been a critical consideration. Compression values for the EPS foam are taken from published and code tested values developed for geofoam blocks for geotechnical uses.

THERMOSHELTER is a lightweight prestressed structure with extraordinary performance under earthquake and high wind conditions. This is a prestressed rigid cellular insulation structure [PRCI].

PORTABLE AND LIGHTWEIGHT

THERMOSHELTERs, based on their simple construction and fastening systems, can be easily disassembled, stored and/or shipped if necessary and quickly reconstructed later. Weighing less than 20% of a conventional building, THERMOSHELTER provides substantial savings in shipping costs, as well, compared to traditional modular or prefabricated structures.

LIMITATIONS

The main disadvantage of a prestressed arch structure is the arch shape itself. It can lack the design flexibility of framed structures. It is not easy to "add to" arch structures, but they do lend themselves to pod-like collections of buildings, connected by passageways. We plan to create added design options in new THERMOSHELTER projects.

In considering size limitations, simple vaults may have unlimited length. Their span is only limited by wall thickness and allowable compression loads of the block insulation.

Additionally, presently neither US or Canadian codes address the use of foam in this thickness. In this regard, appropriate fire retarding characteristics of the internal skin are an important issue.

PRODUCTS AND OPPORTUNITIES

THERMOSHELTER is available, at this time, on an individual, custom designed basis, with or without contractor services. We are also receiving offers for licensing of the technology.

Future products under consideration include sale of architectural plans for various THERMOSHELTER options and the development of kits that would provide maximum ease and lowest possible construction costs.

We are interested in creating additional demonstration models of THERMOSHELTER. If you know of such an opportunity, please contact us to discuss how we might cooperate.

We are also interested in advancing the THERMOSHELTER business. Please contact us to discuss opportunities for investment, partnership and business development.

 

COST OF CONSTRUCTION

Construction cost savings, as compared to a simple wood frame building, are directly related to THERMOSHELTER's simplicity and ease of erection. The cost of materials is a little over $3 per square foot of walls and roof (including interior finishes). The cost of a standard wood frame wall is higher, a standard frame roof much higher. And the more substantial cost savings are realized in long term energy savings (discussed in "energy savings" above).

Once the floor is built, the foam arch for a 1000 square foot house can be erected in two days by two people. The roof strips can be tensioned in place in one day. The simple and lightweight building system lends itself to construction by unskilled labor. As an example, we hope to soon supervise children in building their own THERMOSHELTER classrooms.

THERMOSHELTER 1 (880 square feet) cost $25,000, and took two people per day for four months. (Road, well and shipping cost an additional $10,000.) The 50 shaped foam blocks accounted for $5,600 of that cost. We believe it makes intuitive sense for the largest single expense of such a building to be for its insulation materials.