Julie Lineberger and Joseph Cincotta of LineSync Architecture designed their home with straw-bale, plaster, and a little bit of Yankee ingenuity.
Taking advantage of passive solar design principles, and meeting their electricity needs with solar power, wind, and propane tanks for backup, they were able to take their southern Vermont house off the grid.
In âThe Three Little Pigs,â the big, bad wolf huffs and puffs and easily blows down the first pigletâs straw house. But with rising energy costs playing the wolf at the door, donât dismiss straw houses too quickly. In southern Vermont, Dale and Michele Doucette and their two sons enjoy a large, comfortable home made of straw bales stacked to surround a post-and-beam frame like a blanket.
âStraw walls typically have an R factor ranging from 30 to 50âand if you factor in âair tightness,â they can save energy on the order of an R-70 fiberglass wall,â says architect Joseph Cincotta, M.Arch. â88, who designed the Vermont straw-bale house and even helped sheathe the straw in two layers of plaster. âThe typical wooden-stud wall has an R factor of about 12.â (R factor is an index of an insulating materialâs resistance to heat transfer.) The energy efficiency of the Doucettesâ straw-bale house has enabled them to leave the power grid behind; they meet their needs with solar and wind power, backed up by propane tanks.
Straw has other advantages: it contains a natural fire retardant, for example, making it less flammable than wood. âItâs really hard to light a bale of straw,â Cincotta explains. Yet straw, like wood, is subject to damage by moistureârot. So Cincotta took pains to keep rain water off the walls, widening the typical 12- to 18-inch roof overhang to 36 inches. âSun and rain wear buildings down,â he says, âso good overhang is always good practice.â Nor did they put straw directly on the concrete foundations, he says. âThe first 16 inches of wall are completely waterproofâconcrete and foamâraindrops splash up well below the first bale of straw.â Finally, they took care to ensure that window sills and door openings would not trap water, and that any water that did somehow enter the walls would not remain there, using lime plasterâan old type used in the 1800sâboth inside and outside the stacks of straw. âLime plaster has more clay in it than cement plaster, so it is more porous,â Cincotta explains. âMoisture travels to dryness like heat to cold, so plaster that breathes allows wet straw to dry out.â
Furthermore, the fact that straw bales arenât perfect cubes influenced the design. âI was inspired by the straw to try things I wouldnât do in a wood home,â Cincotta says. The front door, for example, is arched. Cutting wooden arches, forming them, and bending sheetrock are expensive and time-consuming tasks, but arches are far easier to build with straw bales, whose shape is flexible, not rigid. And arches âtend to be a welcoming gesture,â Cincotta says. Influenced by the softer curves of straw bales, he also used curved lines on an outdoor deck and a soapstone kitchen countertop. Even the homeâs plastered walls are not perfectly even and flat. âWe embraced the handmade feel of that,â says the architect. âThose walls have character, and give a sense of soul to the place.â