In 2008, Jesse Thompson, AIA, and Betsy Scheintaub found a genuinely crummy house: a down-at-the-heels 1960s ranch with a wet basement and a failing backyard swimming pool, which the seller had tried to hide by filling in with sand. They were delighted. A partner at Portland, Maine–based Kaplan Thompson Architects, Thompson saw it as the perfect test bed for exploring affordable, energy-efficient, northern-climate remodeling. Scheintaub, a fiber artist, was game for a husband-and-wife design collaboration. Plus, the house was within cycling distance of Thompson’s downtown office. And so began Ranch Revival, a project that transformed an energy-wasting underachiever into a polished, contemporary dwelling that approaches the highest new-home performance standards.

Living in the house with their two children for a year before beginning construction, Thompson and Scheintaub worked up a plan to expand the building from 1,100 to 1,900 square feet, within its existing footprint. “We didn’t want to pour more concrete,” Thompson says. Locating two bedrooms in a partial second-story addition, the couple reconfigured the ground floor to include an open great room, a master suite, and an office/guest room. A generous mud-room entry ties the house to its existing one-car garage.

To upgrade the building envelope, Thompson, who also acted as general contractor, added air barrier elements and 6 inches of recycled rigid polyisocyanurate insulation outside the original sheathing, then filled the existing wall cavities with dense-pack cellulose insulation. The continuous exterior insulation raises the wall’s R-value to R-40 while virtually eliminating thermal bridging. Locating two-thirds of the wall’s total R-value outboard of the structural wall keeps the framing above dew-point temperature even on Maine’s coldest days, Thompson explains. “And if the wood is warm, it’s going to stay dry.” A new I-joist roof over the great room combines dense-pack cellulose and a layer of rigid insulation for an R-60 assembly; a generous filling of cellulose in the truss space of the new gable roof exceeds that value. Triple-glazed windows by Toronto-based Inline Fiberglass—“They’re about R-5,” Thompson says—and stained pine entry doors by the Polish company Drewexim round out the building shell.

Thompson dried out the cellar by laying 2 inches of rigid insulation over the existing concrete floor, pouring a new slab, and applying 4 inches of rigid insulation to the interior face of the foundation walls. Meticulous air sealing—verified with blower-door tests at three junctures during construction—yielded a final reading of 1.0 air change per hour at 50 pascals. “We met the Passive House EnerPHit target for existing houses,” Thompson says. “We did a tenfold reduction [of air infiltration]—with a bigger house.”

To weatherproof the shell, Thompson says, “we wanted to make a tough, low-maintenance exterior using as many local materials as we could.” Hemlock clapboards and white cedar shiplap siding provide a subtle contrast in visual rhythm. The trellises and porch decking are unfinished white cedar. Haunting Habitat for Humanity’s local ReStore outlet, Scheintaub bagged the salvaged slate shingles that clad the chimney and the flared skirt that wraps the ground floor.

Thompson and Scheintaub credit the warm Modernism of midcentury Scandinavian design with inspiring the interior palette. Baltic birch plywood flooring, in 5-foot-square tiles separated with 1/8-inch cork strips, defines the new space. “It allowed us to put down a very affordable hardwood floor that we didn’t have to sand on site,” says Thompson, who used low- and no-VOC finishes throughout. The great room’s existing red oak floor owes its darkened hues to a traditional, home-brewed “ebonizing” treatment consisting of steel wool dissolved in vinegar.

Another Scandinavian import—a high-efficiency, wood-burning fireplace insert by Scan—supplies most of the house’s heating. A 96-percent-efficient Triangle Tube condensing gas boiler provides hot water and supplemental heat. Including firewood, “it costs us about $500 a year to heat the house,” Thompson says. “And it’s the warmest house I’ve ever lived in.” The Zehnder whole-house heat-recovery-ventilator system is so efficient, he says, “that the fresh air coming into the bedrooms in the middle of the winter is at 65 degrees, even if it’s 5 degrees outside.” Energy Star–labeled appliances and LED and fluorescent lighting reduce the household’s electrical load to about 350 kWh per month, which the couple plans to offset completely with a 3.5- or 4-kW PV array mounted on the garage roof.

None of which concerns passersby, of course, but they nevertheless seem to recognize that something special has happened here. “It was the worst house on the block,” Thompson recalls of the now LEED Platinum–certified home—and apparently his neighbors remember that too. “A lot of people walk by and give us the thumbs-up.”

Read more about Kaplan Thompson in EcoHome's profile.