Morning Glory Straw Bale Studio Innovative Use of Natural Building Materials

DESCRIPTION:

In Oxford, in rural Oakland County, construction is underway for a 600 square foot studio with a loft. This studio has a thatched roof, straw bale walls covered with earthen plaster, log frame, finished earthen floor and fieldstone foundation wall. The studio is designed to fit between existing trees on the site, creating an irregular and curving building footprint.

The foundation was dug below the frost line (down to a minimum of 42" to prevent heaving from frozen ground) in the fall of 1996. Foundation work continued into the spring of 1997, beginning with drainage gravel laid on the bottom of the trench. A 1-2 foot layer of fist to head-size rocks were placed on top of the gravel (a partial "rubble trench" foundation). A fieldstone wall was laid 2 feet below and above grade as the base for the straw bale walls. The nine cement piers to support the log posts were poured on the interior side of the foundation so that the log frame would be on the inside of the structure. Salvaged Norway spruce logs were used for the round timber framing and roof.

Over 1,200 bundles of reed collected in St. Clair County during the winter of 1997-98 were used to create a thatched roof for the building. The remaining 500 bundles of reeds needed to complete the roof were collected this past winter and spring. Completion of the thatching is scheduled for spring. The underside of the thatch roof will have a layer of earthen (local clay) and straw plaster for fireproofing.

The north, east and west sides of the structure are 2-foot side bales of straw with an insulating factor of a miniumum of R-40. The south wall has 5 large windows for passive solar gain. All wall surfaces will be finished with earthen clay plaster. A few interior features, such as bookshelves and benches will be sculpted from "cob". Cob means "lump" or "rounded mass" in old English and refers to a clay, sand and straw mixture used for building in England and Europe for centuries.

The floor will have a gravel base covered with 3" layer of poured adobe (another clay, sand and straw mix). The floor surface will be hardened and waterproofed with linseed oil and bee's wax.

The studio will have no plumbing. Water to a sink will be provided by a canister or small tank with a spigot, mounted above the area. Heating will come from a wood-burning stove and passive solar design. Electricity will be produced by photovoltaic panels donated by Detroit Edison.

STRAW BALE CONSTRUCTION:

Straw bale buildings boast superinsulated walls, simple construction, low costs, and the conversion of an agricultural byproduct into a valued building material. Properly constructed and maintained, the straw bale walls, stucco exterior and plaster interior remain water proof, fire resistant and pest free.

People throughout history have used whatever indigenous materials were at hand to create shelters. In tree-poor areas of the United States, people often used sod to build. With the advent of the baling machine in the 1890s, straw bales were employed in such areas as a building material. Straw compacted into bales offers much better insulation with its high thermal resistance than sod or wood. Tests following ASTM procedures resulted in bale R-values between R-2.5 and R-3.0 per inch, depending on the direction of the straw, giving the finished wall an R-40 or above rating.

The two primary ways to build with straw bales are load-bearing, or "Nebraska" style, and post-and-beam in-fill. In load-bearing straw bale construction, bales are stacked and reinforced to provide structural walls that carry the roof load. With in-fill straw bale construction, a wood, metal or masonry structural frame supports the roof and bales are stacked to provide non-structural, insulating walls. With either alternative, the bale walls are plastered or stuccoed on both the interior and exterior.

The advantage of the load-bearing style is that it uses less wood, thereby conserving cost and trees. The advantage of the post-and-beam method is greater design flexibility. Straw bale construction, with either method, partners well with passive solar design. The highly insulative straw bale walls allow a greater retention of the sun's heat brought into the building through southern-oriented windows.

FOR FURTHER INFORMATION CONTACT:
To find out more about straw bale structures or to volunteer on this project, contact:

Deanne Bedner 2641 Warner Orchard Lake, Michigan phone: (248) 363-1756 fax: (248) 363-8896	Fran Lee 2691 Noble Road 48324 Oxford, MI 48370 phone: 248/628-5283
Carolyn Koch 810 Plate Street #207 Rochester, MI 48307 phone: 248/656-9456	Gregory Matthews 2900 Heidelberg Rochester Hills, MI 48309 phone: 248/375-0163

To read more on the Morning Glory Straw Bale Studio, building updates and links to Natural Building, visit the web site at: http://www.geocities.com/rainforest/vines/7729

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Main Telephone Line: (517) 241-6228
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Energy Office, Department of Consumer and Industry Services
Office of Policy and Leglislative Affairs
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Lansing , MI 48909