Author wrote the book on home building, then wrote some more

In 1998, Sheri Koones left the canyons of Manhattan for suburban Greenwich, Conn., where she and her husband Rob had bought a 45-year-old house that they deemed the perfect place to raise their two young children.

From the outset, the couple knew that the house needed a lot of work. In fact, they basically rebuilt it. Such major surgery required the services of an architect and a homebuilder.

Sheri Koones said she had no idea how to undertake such a daunting project: how to find an architect, what that might cost, what to expect, or how to evaluate a contract. Ditto for a homebuilder.

Koones checked out every book on homebuilding and home design from her local public library, but none of the more than two dozen books she perused was very helpful. "I flew by the seat of my pants," she said.

Luckily, the project turned out well. But Koones, a former New York City teacher, decided that she wanted to understand the whole process with greater clarity and to demystify it for the average person. Thus began a new career.

Other than her own experience, Koones had no background in homebuilding, but this was an advantage. She knew what the average person faced when trying to build or remodel. Koones's first book, "From Sand Castles to Dream Houses" (Hanley Wood, $25), focused on finding the right professional, what questions to ask in an interview, evaluating the work and assessing fees. She also presented a typical sequence of events from a sketch to the final design and its construction. To help readers stay on top of all this, she showed them how to draw a timeline to help plan for a momentous project. Her second book, "House About It," (Gibbs Smith, $24) got into the nitty-gritty of design and construction with short tutorials on the myriad and befuddling choices on virtually everything that goes into a house.

For her third book, "Modular Mansions," (Gibbs Smith, $30) Koones moved from the general to the specific. She had become fascinated with modular housing, a type of factory-built house that is still largely unknown in the United States, though it is common in Europe. To the extent that the public knows anything, Koones said, they assume that modular housing means "boxy, little, ugly houses" or trailers, now called manufactured houses.

The distinction is confusing, Koones acknowledged, because modular houses are made up of multiple boxes that are similar in size to a single- or double- wide trailer. But, Koones was quick to point out, a modular house can be multistoried and the number of boxes per floor is almost limitless. Once the boxes are craned into place, the house is indistinguishable from one built onsite. The modular process allows for tremendous flexibility in designing a floor plan and choosing an architectural style. As she made clear in her book, a modular house can be spare and modernist, comfortably Craftsman, Georgian, colonial or rustic.

For Koones, the advantages of a factory-built house were especially appealing after watching her own home become drenched by daily rains before it was finally enclosed. She also appreciated the speed that a factory allows. Start to finish, a modular house can be completed in three to eight months, but a large, custom, site-built house might take up to a year, she said.

In 2005, when "Modular Mansions" was published, the housing boom was in high gear and big houses were popular with buyers. Wanting to demonstrate that size should not dissuade anyone from the modular approach, one of the 20 houses Koones profiled is a 26-box, 12,700-square-foot colonial vacation home on Cape Cod, Mass. Nine others have 4,000 to 9,800 square feet, large by today's standards.

With "Prefabulous," (Taunton, $25) Koones broadened her focus on prefabrication to include other approaches that speed up the building process. Instead of fabricating entire rooms or parts of rooms, factories make components that can be fashioned into walls and roofs using concrete, logs, conventional wood studs, metal studs, timber frames or structural insulated panels, commonly called SIPS.

With her latest book, "Prefabulous + Sustainable: Building and Customizing an Affordable, Energy-Efficient Home," (Abrams, $25), Koones focuses on the sustainability of prefabrication, which she characterizes as "intrinsically green" because it is far less wasteful than conventional, site-built construction. Delivering a stunning truth that most homeowners never consider, Koones states that waste costs both the buyer and the builder: "You pay for everything that goes into your house, including what's thrown away. On top of that, you pay for the dumpster that holds the waste; you pay for it to be hauled away, and you pay the 'tipping' charges at the dump when the waste arrives."

Moving beyond the waste issue, Koones makes a commendable effort to demystify "green" building, which most people equate with costly photovoltaics on the roof. They don't realize that much of a green-building approach focuses on cost-free ways to make a building more energy-efficient, and these apply to any house, prefab or not.

For example, Koones said, when a house is properly sited on a building lot, the owners will be able to tap the free heat of the sun in winter. Generous overhangs and strategically placed, shade-providing deciduous trees can keep the unwanted sun out during long, hot summers. Strategically placed and properly sized windows can provide most of the illumination needed during the day.

Though Koones does not specifically address the size issue, the houses presented here are notably smaller than the ones in her earlier books. The smallest is 725 square feet, the largest is 4,600 square feet and most of the 24 houses featured are in the range of 2,000 to 2,500 square feet.

As in her earlier books, Koones writes accessibly for the general reader. Still a teacher at heart, she said, "I want to make things simple. I'm never talking over someone's head. It's not useful if my readers don't understand it."