The $15,000 Solar Arcade

Two of MOTHER’s staffers recently visIted the prototype
Solar Arcade-near Orange, Virginia-and found it a light and
airy dwelling snuggled into a south-facing hillside. Angus
is concerned with making his structures not only
functional, but affordable and easy to build as well . . .
following a concept he refers to as “anxiety-free,
energy-efficient housing”. His investigation into, and
subsequent use of, modular techniques has grown out of his
work experience over the past few years.

“I’m constantly amazed at the low cost of well-finished
modular housing, and also at the instant availability of
house-trailer accommodation,” Macdonald says. He came to
that appreciation most strongly during his involvement with
the development of a low-cost housing project in Jamaica,
where Angus and a six- to eight-man crew were able to erect
a panelized, three-bedroom dwelling-complete with
services-within seven days . . . fore total cost of
$6,000.

This astounding accomplishment remained in the architect’s
mind as he returned to his work in the States. Angus began
trying (successfully!) to meet his clients’ demands for
comfortable, spacious living quarters without the burden of
huge mortgage payments (he estimates that eight of the
houses he’s designed during the past year have been
completed for less than $40,000). As his work progressed,
Macdonald came to realize that he could combine the
energy-efficient attributes of earth-sheltered housing with
the labor- and cost-efficient benefits of prefabricated
construction … and the earth-sheltered, passive solar
module was born.

TAKING THE HEAT

Angus decided that a south-facing, direct-gain passive solar
system would be the simplest and least expensive way of
heating his dwellings. The combination of concrete and
reinforced masonry acts as a heat sink, and the material’s
mass is balanced against the size of the collector area
(which consists of sloping fiberglass installed above the
windows) to provide optimum performance throughout much of
North America. The roof angle permits maximum exposure of
the dark-colored interior rear wall in winter and less in
spring and fall . . . since an overhang and projecting fins
protect the glazing against summer sunlight (in fact, the
summer sun’s rays will strike the collector area only in
early morning and late afternoon hours).

“Through the basic geometry of the plan and the shape of
the dwelling, we’ve devised a house that responds to all
seasons . . . without requiring moving parts, complicated
machinery, or expensive and unusual building materials,”
Macdonald points out.

Earth sheltering, of course, plays a large role in helping
the Solar Arcade maintain a stable year-round temperature.
And, in the part of Virginia where the model home is
located, summer cooling is just as important as is winter
heat.

Happily, then, the flywheel effect of the earth’s crust
works throughout the year upon the buried portions of the
walls and subgrade floors: The soil takes all summer to
warm up and all winter to cool down … hence, subgrade
temperatures are remarkably stable throughout the seasons.
At Orange, Virginia’s latitude, the ground temperature
fluctuates, on the average, only between 58° and
65°F.

Angus has had a chance to evaluate his earth-sheltering
theories, too. The house that he designed for the Bresee
family, for example (it was featured in MOTHER NO. 67), has
maintained a nearly constant 70° interior temperature
through the winter . . . without the aid of a woodstove,
backup electric heat, or even the acrylic solar greenhouse
panels that the builder originally intended to install on
the south facade. Likewise, the house has proved to be
comfortably cool during the summer.

The Arcade is designed to incorporate a woodstove for
auxiliary warmth, but Angus recommends that homeowners who
face building code restrictions install electric baseboard
heat as a backup system … since it’s inexpensive,
satisfies the regulations, and lends itself well to
zoneheating. To facilitate the flow of warm air from room
to room, Macdonald has left openings, at ceiling level,
between the exposed beams. Furthermore, the home’s
south-facing exposure all but begs for a solar domestic
water heater . . . and Angus’s plans make provision for
such an installation.

MODULAR MATERIALS

To assemble a Solar Arcade, the builder first constructs
the masonry shell, and then frames the residence . . .
either using the precut timber kit or cutting the members
to specification. (The timber package, which can be shipped
to a do-it-yourselfer, is made up of oak beams with
mortise-and terion joints, for which pegs and a mallet are
provided. The builder will need to use a drill for
assembly, though, since the holes are bored after the
members are fitted together . . . to insure tight joints.
The kit costs $2,500, but a set of cutting diagrams and
execution drawings is available, for $50, to those who wish
to shape their own framing timbers.)

After the masonry shell has been framed, the roof deck is
sheathed with plyform, a heavy oiled plywood chosen be
cause of its strength and water resistance. The roof and
walls are then covered with Griffolyn triple-layered
polyethylene. (Commonly used for truck tarpaulins, this
material is completely waterproof, extremely strong,
and-since a nylon fishnet is laminated between its
layers, tear-resistant.)

Before the backfilling takes place, foundation drains are
installed . . . and, in wet regions, more drains are added
at roof level. Finally, a mixture of topsoil and peat moss
is layered over the fill earth.

A ROCK-BOTTOM COST

The Solar Arcade’s $14,757 price tag can be broken down
into $10,627 for materials and $4,130 for labor. (Angus
points out that folks who live in urban areas will likely
have lower materials expenses, which will probably be
offset by somewhat higher labor costs.) Of course, if a
person can do his or her own masonry and/or can cut the
framing timbers from the diagrams-in addition to finish
carpentry and the like-the total building expense could be
significantly lower.

The basic Arcade is somewhat Spartan in appearance, leaving
the owner considerable leeway in finishing off the home’s
interior. Macdonald’s intention is to construct a livable
earth-sheltered house at a reasonable cost . . . therefore,
a large portion of the building budget is spent on
high-quality, durable components-such as well-made doors
and Andersen windows rather than on “decoration”.

Angus believes that a builder, particularly a first-time
homeowner who’s likely stretching his or her financial
resources to the breaking point, will prefer to add ceramic
tile, custom cabinetry, or other appointments later . . .
as money becomes available. And the dollars should be there
for the spending in a relatively short time, since mortgage
payments and utility bills will have been kept to a minimum
from the outset.

There’s an additional financial benefit for a would-be
Arcade builder, too: Because of its heavy timber frame and
masonry construction, the home has been rated as
practically fireproof by a Virginia insurance agency, and
premiums to insure the dwelling “against all perils” amount
to less than $100 a year.

Plans for the Solar Arcade-which include working drawings,
a cost analysis, and a specification booklet-are priced at
$100 a set. They may be ordered from Survival Consultants,
Dept. TMEN, P.O. Box 21, Rapidan, Virginia 22733. (Angus
also encloses a suppliers list … which contains a
description of-and access information for the specific
materials he recommends for waterproofing, structure, and
finishing.) Plans for a modified two-bedroom version of the
Solar Arcade are available, too .. . and any inquiries
about the precut heavy timber kit or the cutting diagrams
should be directed to the same address.

EDITOR’S NOTE: Survival Consultants offers acatalog of all the organization’s standard home plans
for $5.00. . . and precut framing kits, similar to the one
designed for the Solar Arcade, are available for some
of the other houses as well.

Angus Macdonald will also work with clients
in helping modify his standard plans, and in providing
custom design work.