Tiny Passive Solar Cabin

The streamlined shape of this 120 square foot fort is derived from a need to fit into a small yard without closing off the patio.

and also to make the best use of the square footage inside.

The wider north end affords enough space for a 7’- 6” built-in couch (long enough for a tall adult to comfortably stretch out for a nap,) and the narrower south end is plenty wide enough for a workstation.

The built-in couch, supported by ¾” tube steel and plywood, allows for storage underneath in rolling drawers.

The curved desk surface makes it possible for three or more people to study a set of plans together.

The south end has a low ceiling height to allow for a high south facing window above, and is a cozy niche for sitting at the desk. In the winter time southern sunlight will stream into the space and warm up the north wall that has an extra layer of sheet rock to store the heat.

A major goal of this project was sustainability and we made many environmentally conscious choices besides the compact size of the studio.

Here is the list:

The concrete slab has 30% flyash replacing the portland cement.

Almost all of the framing lumber and plywood is FSC certified. (A couple of times we bought non-certified materials rather than drive across town to pick up up one stick of lumber.)

The rainscreen siding and part of the desk is made from a redwood tree that was cut down for road clearance and milled by Matt Mcbride with a portable mill.

All the finishes (interior and exterior paint & clear wood finishes) are zero VOC or low VOC and some are biodegradable.

(Manufacturers of finishes: Earthpaint, Bioshield, AFM Safecoat, Penofin, & American Pride)

The exterior light is LED (7 watts) No lights are required on the inside during the day.

The walls and ceiling are insulated above Title 24 Standards for the zone, and all the cracks and crevices are sealed with expanding foam. This means that the computer and myself provide enough heat for all but the very coldest days. Cracking the high window seems to be enough on a warm day to keep the interior temperatures comfortable.

The windows on the south side have a special type of glass that lets the sun's heat in, but does not allow the heat to escape from inside. I havent been in the studio for a winter yet, but so far it stays cozy with no heating system except the sun, the computer, and the occupants (usually myself and sometimes a large dog.)

The next few shots show the unfinished interior.  Check back for updates!