The primary solar features used in our coop are south-facing windows, thermal mass to
store heat, and outside insulation and insulated window panels to keep that heat in.
SITING: Since the coop could be dry inside only if the building site was high and dry, we
dug several test holes a foot or so deeper than the planned excavation, and checked them
later to be sure no water had seeped in. Then, to ensure maximum solar efficiency, we
checked the site for both morning and afternoon shading problems. In our case, we settled
on a sort of compromise -- direct sunshine from dawn until about 4 pm when, in the summer
only, the leaves of an adjacent woodlot (maples, birch, and basswood) provide partial
shade for the coop.
EXCAVATION: The dimensions of our coop were determined by estimating the size flock we
wanted (20) and multiplying that number by four square feet per bird. As it turned out,
eight-foot-long interior walls, using a five-sided shape, yielded a floor area of 85
square feet. Since our foundation logs averaged eight to twelve inches in diameter, we
staked out the site a couple of feet larger than the interior dimensions. The edges of the
pit were cut as vertically as possible, and most of the dirt was
piled on the north side.
FOUNDATION LOG WALLS: When the excavation was about three feet deep and the bottom
leveled, it was time to begin laying the walls. The logs had been previously cut, peeled
and sorted by size. The largest diameter poles, for the bottom tier, were notched on the
top side with a chainsaw and axe (Fig. "a"), and subsequent logs were notched on
both top and bottom (Fig. "b").
Each piece was laid temporarily in place until all adjacent logs were matched to it and
irregularities between them removed with an axe or adz. Then the log was removed from the
wall and coated on all surfaces with black waterproof roof sealer. If cedar, cypress, or
treated poles has been used, this laborious step could be eliminated. But we used what we
had -- Balm of Gilead, or Balsam Poplar.
When re-placed in the wall, the logs were secured at each end by a single
"spike", actually a short (10 to 18 inch) length of 3/8 inch steel reinforcing
rod. Care was taken to be sure that no spikes were placed where the door opening would
later be cut. Logs were laid until a wall height slightly above the
original ground level was reached.
FRAME UPPER STRUCTURE: To facilitate insulation of the above-ground portion of the
structure, standard 2-by-4 frame construction was used. Only slight modifications were
needed to accommodate the transition from logs to dimension lumber (Fig. "c").
Double vertical studs were placed in the middle of the two north walls and at their
junction to provide support for the three stout maple rafter poles. Likewise, the midpoint
and each end of the south wall were framed to support the other ends of the poles.
All openings were made to match the dimensions of the old windows and door we had
scrounged up. Exterior wall boards were nailed on at this point to give
rigidity to the structure while the roof was being put on.
ROOF AND WATERPROOF COVERING: The roofing job consisted of notching the three rafter
poles, setting them in place, hacking off the most obnoxious upfacing knots, and nailing
on roof boards. We tried to save the strongest, smoothest, and widest boards for the roof.
Any sharp or ragged edges or knots which could have punctured the roof covering were
planed or filed smooth. Roof and wall covering material was applied in one operation to
avoid any possibility of leakage at a roof/wall seam.
We literally wrapped the entire building in roofing felt (tar paper scraps and roll ends
left over from building our cabin). The purpose of this layer is not so much to provide a
moisture barrier, but to protect the next layer - polyethylene film - from the roughness
of the wood.
Next we carefully draped a single sheet of six-mil polyethylene over the whole building.
The film extended from the bottom row of logs up over the edges of the walls, with all
excess left temporarily on the roof. This extra material allowed the film to creep down
along the walls during backfilling, without stretching or tearing.
Just before backfilling, several layers of foam boxes (salvaged from a cable tv company)
were stacked up between the sheeting and logs. Our boxes tested out to have an
"R" value of four, not including the insulating value of the air spaces inside
and around them. An "R" factor of eight to ten should be adequate for this type
of below-ground application.
Soft, clean sand was gently shoveled against the wall, the trench around the coop finally
filled in. Straw bales were stacked against the north walls and around the east and west
corners up the eaves' height and tapered away from the building to provide a smooth
contour into the surrounding area. [See note at end concerning using straw for backfill.]
Foam boxes were arranged on the roof and then the whole thing, including surrounding
bales, was covered with a few inches of light soil and a thick straw mulch. From the
north, the coop looks like a rather casual pile of straw.
FINISHING TOUCHES: We put a little trim around the windows, doors, and the edge of the
roof, nailed some cedar boards on the exposed exterior wall surfaces, and then the outside
of the coop was finished.
Inside, fiberglass insulation (some of which was salvaged from old hot water heaters) was
put into the walls, and interior wall boards were nailed up. A coat of paint (white on the
upper board walls, dark brown on the lower log walls), roosts made from ironwood saplings,
nest boxes hung on the wall, and a pickup load of dry, coarse sawdust completed the
During the winter, we added an insulated panel to cover the front window and to help
retain both heat absorbed by the dark-colored log walls during the day, and the
significant amount of heat given off by the birds.
Well, that's all there is to it -- a couple of weeks of good, healthy exercise, a few
dollars for materials we were unable to scrounge, a lot of fun . . . and the chickens love
NOTE -- 1999:
From Sue. The chickens made this coop their home for some eight years,
and thrived. It worked well for them and for us. The chickens are now gone, but the coop
still stands, twenty years later, and is well utilized as a garden shed. There is a leak
in the roof now, and next summer we are going to unbury and strip the insulating boxes and
plastic off to repair and recover the roof covering.
The early straw bales worked as backfill only until they started to break down, which of
course they did, settling and exposing the upper part of the coop to the weather. We
wrapped the exposed area in sheets of dark colored, closed-cell foam we had left from our
house building, and told ourselves we'd get to properly burying the coop soon. Meantime,
we piled brush and apple tree branches from pruning and trimming around the back of the
coop to hide the ugly foam.
Well, soon does come sooner or later! And on the homestead, it is usually later. We did
add some extra dirt around the coop some years ago, but not enough to reach the roof. The
roof itself has a wonderful, living covering of moss and weeds living in its six or eight
inches of dirt. We will be sorry to have to disturb that covering, but if we plan on the
building lasting at least another twenty years, the later will have to come soon, and the
old chicken coop will finally get its new covering and dirt surround.
NOTE -- 2009:
From Sue. And things change ... The old coop served us well for so many
years but those leaks are the bane of any builder who wants things to last. We
decided it was time to let the coop, and that part of the garden, rest in peace.
So we rearranged our storage building to accommodate the tools from the old
garden-shed-coop and in 2002 dismantled the building, filling in and
more-or-less leveling the ground. We salvaged as much as we could and many
boards (which were themselves salvaged from elsewhere) are found new uses on the
homestead. In its place we planted a pear tree (which a few years later I moved
because it was in the way of my expanding grape row). Sigh -- if we could only
get it right the first time, how much time we'd save. But that wouldn't be much
In 2006 it
was obvious that the cedar posts we'd built our storage shed on way back in 1978
were well rotted and the sinking building wasn't getting any better. We took
stock of what was in, what room was elsewhere, and started cleaning house. We
squared off our added-on-to-again-and-again cabin-turned-shop building and
gained a small room for a garden tool shed. Some stuff went to St Vincent de
Paul and the Habitat Restore. The local metal recycler got a good load when he
came to pick up a finally retired old car. A bunch found room in the hangar
(which has no plane). Then we added a lean-to on the hangar for the rest. Such
is the life on the homestead.
* * * * * *
© 1979 - 1999 - 2009 by Stephen Schmeck and Susan Robishaw