Miles off the paved highway and at the end of a long, bumpy driveway that cuts deep into the woods, Mick Womersley puts the finishing touches on his solar panel-topped home in Monroe. It’s not your ordinary rural dwelling, even one designed to be ecologically sound.

Womersley, a human ecology professor, and his wife, Aimee Phillippi, live comfortably in a house built of roughly 200 straw bales.

Their home bears no resemblance to the one blown down by the wolf in the children’s story. Strong and solid, the walls have insulating capacity several times that of conventional homes, offering more than ample protection from winter temperatures that can persist in the single numbers for days.

Coming from a source that renews itself annually, straw is cheap, and it’s not an attractive food source for insects. And its proponents note that once the tightly packed straw is covered with stucco, it catches fire at a higher temperature than wood.

All of which leave Womersley, who’s in his 40s, and his wife, who’s just shy of 30, cozy in the winter and cool in the summer. They have no mortgage and only about $6,000 in credit card debts from building the home they share with two dogs. They have no children.

Separated from the woods road by vegetable gardens and a pen for their pigs, their home is off the power grid and completely self-contained.

Womersley takes special pride in the fact that it’s built entirely from recycled or renewable materials. The construction cost came to less than $20,000.

“Every piece of junk that went into this house has a story,” the red-bearded, bespectacled professor said with a slight hint of an accent that gives away his British background.

The wooden planking on the floor came from a former chicken barn. The large windows that admit floods of sunlight were donated by neighbors or bought secondhand, and one even came from Unity College, where Womersley and his marine biologist wife teach. The small private school offers a curriculum that emphasizes the environment and natural resources.

Wooden sheathing and studs that enclose the straw bales had previous uses before being salvaged by the couple. Much of the wooden framing in the post-and-beam structure was hewn from trees that were cut on the site, which Womersley believes was an orchard long ago.

“This was an old farm, we’re just reinhabiting it,” he said as cool gusts on a cloudy July afternoon swept across the lot, which Womersley is leasing for 99 years.

The project started in 2002, not as an experiment in environmentalism or showcase in self-sufficiency, but rather out of financial necessity.

“I was paying rent in Belfast, and with utilities, that was $900 a month,” said Womersley. “That’s a lot of building materials. … We wanted a house that would save energy but would also be really cheap.”

He cleared the land, dug trenches for a rubble base to a cinder block foundation and built the kitchen section so he would have a place to live while the rest of the house went up.

Spring runoff that made a muddy mess of the driveway threatened to derail the project, but Womersley forged ahead. Mixing information he gleaned from books with his own ingenuity, he built framing to support the rest of the house and roof, which is split at the top to accommodate roofline windows.

Erecting the straw walls involved much more than just piling up the oat and barley straw bales, which cost anywhere from $2 to $7 depending on what was available. The cost is far less than that of traditional building materials.

Once the bales were stacked, recycled foam board was placed along outside walls before they were covered with sheathing and cedar shingles. Inside, the bales were enclosed by clay adobe on chicken wire, and topped by white lime plaster, leaving the roughhewn framing attractively exposed.

The main heating source is a wood-burning stove, though the house also has a propane cooking stove and refrigerator. Propane also heats the water, which is drawn from an old farm well.

Solar power provides the bulk of the couple’s electricity. Power is stored in a bank of golf-cart batteries stowed neatly under a wooden step between rooms.

A fluorescent light brightened the home during a recent visit, and other fixtures were equipped with highly efficient bulbs. But Womersley, who believes that living sustainably and comfortably aren’t mutually exclusive, said his television viewing is unhampered by his energy-saving ways.

“You watch TV, and we’re going to watch TV, too,” said Womersley, noting the couple has dish satellite service.

The couple did splurge on a $1,500 backup propane generator, which Womersley proudly fired up with the push of a button. It’s especially useful as a heat backup in the winter’s coldest months to keep the 900-square-foot house cozy.

“We have a house here that runs on very little petroleum and that might be important one of these days,” said Womersley, whose doctorate from the University of Maryland was awarded for a dissertation on global environmental policy and religious environmentalism.

While he takes his area of expertise seriously, Womersley believes that the environmental purists’ ideas are often impractical and even elitist at times.

To Womersley, it makes no sense to build a sustainable house that costs more than a working person can afford or whose parts can’t be obtained from mass-market sources like Wal-Mart or Home Depot.

Phillippi noted that solar heating and power systems can be prohibitively expensive because they aren’t designed for people who need smaller systems. “Designer” straw houses on the market that can cost $450,000 defeat the purpose of being cost-effective, Womersley believes.

In addition to the $20,000 cost of building his home, Womersley said monthly costs of running and maintaining it come to about $250. That compares to rental costs of around $700 per month for decent family apartments in the central Maine area, he said.

Builders have long recognized the usefulness of straw bales, according to the Sourcebook for Green and Sustainable Building. Many straw structures built by homesteaders in Nebraska more than a century ago are still in use, the Internet publication says.

The idea may have migrated from New England, where straw ice houses appeared in the mid-1850s, says The Last Straw, an Internet journal about straw-bale construction.

The technique has become so popular among those looking for a low-cost alternative for heavily insulated walls that straw building codes have been adopted in states including California and New Mexico.

In Washington state, where builder Bruce Glenn counts 50 straw homes, the bales remain dry in a 13-year-old house in an area that gets 85 inches of rain per year.

A variety of structures from airplane hangars to schools and churches are straw-constructed, the Sourcebook says.

Finding alternative uses for some of the 200 million tons of waste straw generated each year in the country decreases greenhouse gas emissions because less carbon monoxide is generated, according to those who advocate its use.