Straw Bale Construction Lisa Patrick, Matt Tosi, Anna Kovaliv

What is it? Environmentally friendly building method that uses straw bales as structural elements and/or insulation

What is it? Straw is the stalk left over after cereal crops such as rice, wheat, and barley are harvested.

Has been used in construction ever since humans have created shelter Used for centuries in Asia and Europe, began as a plaster mixture History

First used in the United States in the Great Plains due to the lack of timber Making a comeback because of high amount of benefits

Self-Supporting Method “Nebraska-style” Use bales as if they were large bricks, compressed with heavy material Plastered on both sides Usually limited to one story

Self-Supporting Method

Use bales as insulation within an existing frame Plastered on both sides Allows for any size house to be built Most widely accepted method in the United States Post & Beam Method

Benefits Green Building method using an annually renewable resource Uses less energy consumption to harvest, produce, and transport bales than conventional methods (timber) Directly supports local economy

Benefits Utilizing a waste product of an existing industry Annual carbon monoxide production from power plants and straw burning SOURCE TONS BURNED TONS OF CARBON MONOXIDE RICE STRAW 1 MILLION 56,000 WHEAT STRAW 97,000 5,000 POWER PLANTS 25,000 California Agricultural Magazine, Vol 45, (1991)

Benefits Energy efficient due to high insulating value (R-value) Walls constantly breathe, circulating air, while still providing superior thermal insulation Walls are very soundproof

Concerns? Is my house going to burn down? No! The bales hold enough air for good insulation but compacted tightly enough to discourage combustion. High silica content in straw impedes fire The plaster can reach temperatures of 1850 degrees F for 2 hours before cracking.

Will bugs or rodents eat my house? No! There is no nutritional value in straw Burrowing can be limited by careful plaster application and tightly woven wire mesh surrounding bales Concerns?

Will my house rot? No! Walls are breathable enough that condensation is limited Concerns?

Questions?

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