Spacious and spare with glass everywhere, e-House redefines daylighting. The ?light catcher? is a soaring space, 20 to 24 feet in height, that tilts to the southeast.

e-House began its life in 2000 as an idea for a high-performance, website-controlled building posted on architect Michael McDonough's website. Before long, the idea had grown into an experiment utilizing the input of a team of engineers, scientists, and environmentalists, along with high-tech sustainable building products from more than 100 manufacturers.

When this magazine visited e-House in 2003, the building was in its early stages—an empty concrete structure hidden away in the Vly, a woodsy hamlet located northwest of Stone Ridge.

Today, the 2,200-square-foot e-House stands nearly completed—a stylish weekend home for the New York City–based McDonough and his family, as well as a showcase for sustainable building that is attracting attention from both green and conventional architects and builders, environmentally savvy members of the public, and national and international media. In January, e-House's "most teched-out" kitchen was noted as one of "The Coolest Rooms on the Planet" by Wired magazine. McDonough, who is writing a book on e-House, is also one of the architects featured on Design: e2, PBS's new series about sustainable building, narrated by Brad Pitt, which began airing in June.

A tour of e-House is perhaps best experienced starting on the rooftop, where, one warm Saturday in May, this reporter found McDonough chatting with a couple who had discovered e-House online and traveled up from New York City to explore the idea of building something like it. (McDonough recently designed a house in Fishkill with modular home models that incorporate several elements of e-House.) "It's all about the site; once you find the land you love, you're there," McDonough noted.

On the rooftop, we could glimpse both the Catskill Mountains and Ashokan Reservoir, as well as gaze down into woods edged by old stone walls, a meadow, and the sites of a future small-scale biodynamic farm featuring high-tunnel greenhouses for a longer growing season, as well as a private walled "inner garden" for ornamental effect and the use of McDonough's wife, chef Corrine Trang. McDonough is working with Stone Ridge's Blue Marble Farms, LLC, on the agricultural components.

Walking up the "recreational roof's" wide steps—inspired by the monumental roof stair of Casa Malaparte, a mid-20th-century house on the Italian island of Capri believed by many architects to be the most beautiful house in the world, and the subject of McDonough's first book—McDonough assured the visiting couple that even though e-House has "ended up being more like a laboratory than anything else," its design contains "absolutely no compromise in comfort."

The architect sits in a bamboo chair of his own design.

E-House's "indoor climate" is managed from a cellar utility room, where the heating system uses new TN4 "two-stage" micro-chip thermostats from Tekmar. Stage 1 controls an in-floor radiant system heated from a 95 percent efficient, propane-fired MZ boiler and solar hot water. Stage 2, which is designed to provide quick-response supplemental heating on days with precipitous temperature drops, controls a Lifebreath Clean Air Furnace, which is a heat-recovery ventilator (HRV) with a heating coil inside. The HRV is also used on its own continuously to supply 20 percent fresh air to the house. To cool and dehumidify the house, McDonough uses 50-degree groundwater.A study is underway to determine how the cellar floor slab, a geothermal well, or 30,000-gallon underground rainwater reservoir might best work as sinks, or natural cooling places where excess heat can be dispersed.

"Most people are not going to migrate immediately away from fossil fuel-heated homes; it's silly to expect them to, but if you show them incremental changes, then it makes sense for them to migrate away," says McDonough. "I want to give my clients and builders a road map for step-by-step sustainable building. I'm not an absolutist. For me, I'd like to work a little harder to get people to understand."

Like the rest of e-House, the basement's air is constantly refreshed, and its temperature is maintained so consistently that McDonough built his wine cellar directly below the first-floor fireplace. "The wine cellar is always 57 degrees, even when the fireplace overhead is 1400 degrees," he says. "I put it here to make a point: Insulation is key, and through careful planning you can control anything within a building."