Brittle Power- PARTS 1-3 (+Notes) - Natural Capitalism Solutions

Chapter Fifteen: End-Use Efficiency: Most Resilience Per Dollar 241This astonishing performance can be achieved by various combinations of“superinsulated” tight construction and passive solar gain—capturing and storingsolar heat, even on cloudy days, in the fabric of the house itself, for examplethrough windows facing the sun. (Other techniques, such as double-envelopeor earth-tempered construction, can do the same thing but are not consideredhere.) There are at least a dozen general recipes for building a superinsulatedhouse, but most of them built in cold climates have several ingredients incommon: typically about a foot of insulation in the walls, two feet in the roof,double or triple glazing, insulated night shutters, and virtually airtight construction.To guard against stuffiness or the accumulation of noxious gases,plenty of fresh air is provided by mechanical ventilation through a small air-toairheat exchanger. This simple device, commercially available for two to fourhundred dollars, can recover about four-fifths of the heat in the outgoing air anduse it to prewarm the incoming fresh air (or, in the summer, to prechill it). 14These combined techniques reduce the total heat loss through the shell of thehouse so far that the internal heat gains—from windows, occupants, lights, andappliances—provide most or all of the space heating. Such supplementary heat asmay be needed in an especially unfavorable climate is so little—much less thanthe heat needed for domestic hot water—that it can be provided by slightlyenlarging the sun-capturing windows, or taking surplus heat from a slightly oversizedsolar water heater, or burning a newspaper or a few sticks in a small stoveon rare occasion, or keeping one or two forty-watt poodles. Such houses have alower life-cycle cost (some also have a lower construction cost) than inefficienthouses. They can look the same as ordinary houses or can be built in any desiredstyle. They provide a higher than normal standard of comfort—less noise, lessdirt, no drafts, excellent temperature stability—and do not, if properly designed,require any significant changes in the occupants’ behavior. All the devices whichsave or produce heat can be as automatic and controllable as present thermostats.The examples most often cited for such construction are the SaskatchewanConservation House (considered in more detail below), its hundreds of successorsin Canada and the U.S., and the Illinois Lo-Cal design. These andother types are being routinely built by tract-housing contractors. 15 The governmentsof Canada, Saskatchewan, and Alberta have spread the necessarybuilding information so effectively 16 —over one hundred thousand copies of abuilders’ manual were distributed by late 1981—that more than a thousandsuch houses are expected to be finished by the end of 1982, even though thefirst one was finished only in December 1977.One reason for this rapid diffusion is economics. Contractors who hadalready built a few superinsulated houses reported in 1980 that theSaskatchewan design increased the net cost of building a typical frame house