Double plays old and new

“Double Plays: Old and New” is an essay by John Solso of Tucson (November 2002) that generalizes the Zomeworks “double play” idea — one element doing two thermal jobs — into a design principle: one place, or one component, serving multiple functions rather than a separate room or part for each. Solso appears on the attendee list of Zomeworks’ Double Play Systems conference alongside Baer, Dave Harrison, NREL staff, and Bruce Davis; the essay reads as a fellow-traveler’s contribution to that conversation.

Old double plays

Drawing on an Earth Watch expedition documenting traditional houses in Turkey, Solso traces multifunctional space to nomadic roots: the yurt, “where one space serves as living room, bedroom and kitchen,” and the traditional Turkish room, which since the 11th-century settlement of Anatolia has kept the same clutter-free habit — each room usable for working, sleeping and cooking. The courtyard and veranda are the daytime activity space: measuring dozens of houses, Solso found 90% of verandas placed on the south or southeast of the house for solar access, with wide overhangs sheltering the wall while making the space comfortable. The cumba — an irregular room-part floating over the street, free of the street’s geometric constraints — channels breezes, captures sunlight, and frames vistas at once.

New double plays

The Softub® hot tub: rigid foam insulation doubles as the structure supporting the tub wall, and a heat exchanger wrapped around the pump motor heats the water with heat that would otherwise be wasted — no heating element at all.
Carolyn Roberts’ load-bearing straw-bale house (Tucson, built with her two sons): walls of insulation, a four-sided overhang that both protects the walls and adds living space, a sun space that is winter living room and solar collector, and a batch water heater whose night lid doubles as a daytime reflector.
Milagro cohousing (Tucson, 28 dwellings on 43 acres, 35 preserved as desert): permaculture doctrine that every element — berm, swale, basin, roof — have more than one function. The 18″ permaculture basins collect rainwater and provide habitat, food, and landscaping; metal roofs harvest water and carry solar water heaters and photovoltaics at the optimum angle.

Solso’s thermosiphon experiments

The essay’s direct link to the Zomeworks program: in summer 2001, “with Steve Baer’s encouragement,” Solso filled a styrofoam box with water and created a thermosiphon through a copper heat exchanger exposed to the night sky. He then built an indoor thermal storage of 4″ PVC pipes (16 gallons) connected by heater hose to a 5-square-foot copper heat exchanger on the roof — it cooled the storage by about 7–8°F overnight. Problems: fitting the PVC, bubbles in the hoses, and leaks. After an eleven-foot mockup, a full-scale system was planned for a Milagro triplex, with aluminum BigFins™ night radiators on the west-facing roof above first-floor water storage; for winter, unglazed black panels on the limited south roof with a PV-powered pump — or the same BigFins used for heating as a “double-play.”

Why it matters

multipurpose room + solar access + simple envelope = better use of space

The spatial lesson matches the rest of the archive: let the building do several jobs at once. A room can be both sheltered and solar-oriented, just as a roof can be both weather surface and thermal collector. Solso’s essay is independent evidence that Baer’s double-play idea traveled — an outside practitioner replicating the night-sky thermosiphon at small scale and folding it into a broader multifunction design ethic.

Double plays old and new

Old double plays

New double plays

Solso’s thermosiphon experiments

Why it matters

See also