The Construction of MOTHER'S Bioshelter Greenhouse

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Here are the details on the latest addition to our ongoing self-reliant homestead project.

In our last issue, we reviewed the progress made at — and plans for — MOTHER's self-reliant homestead, and gave you a glimpse of new construction at the site. This time we offer the construction details on our latest project: a "bioshelter" greenhouse that integrates plant propagation, food production, and chicken and rabbit quarters. This unique family-size structure gets its winter warmth from the sun, livestock body heat, actively decomposing compost, and — in the coldest weather — a catalytic kerosene heater. (It's also specially designed to distribute maximum heat to the growing bed's soil, increasing production by boosting the bed temperature to 80°F.) As you can imagine, this multipurpose structure is rapidly becoming the hub of horticultural activity at the homestead. We'll report more on how it works — and how to work it — as we gain experience. Here we'll go into building it.

The structure of the greenhouse is conventional. Six-inch block walls — reinforced in alternate cavities with concrete and 1/2" steel rods-rest on 8" X 12" poured footings. All of the masonry walls are either backfilled or bermed up with earth for energy efficiency. Above the grade line, stud walls rise with insulated 2 X 4 framing. The roof framing consists of rafters on 24" centers. In the rear, 2 X 6 rafters are covered with 1/2" CDX plywood, 15-pound felt, and roll roofing. The spaces between the 2 X 6's are filled with fiberglass batt, a 6-mil vapor barrier is stapled to the underside of the rafters, and the interior is finished with rough-sawed, random-width, board-and-batten siding. The glazed front roof must bear the weight of 3/8" X 4' 8" X 8' 8" sheets of tempered glass, so the rafters under the joints of the panes are full 4" X 6" beams. Alternate front rafters are 2 X 6's, and all the lumber contacting either glazing, sills, or growing beds is pressure-treated.

The array of diagrams and photos on the next two pages should offer sufficient detail to allow anyone with building experience to duplicate the greenhouse, but we'd like to share a few extra notes and tips that may be helpful.

NOTES ON CONSTRUCTION