Composed of 220 aluminum "light shelves," the solar reflector screen is the focal point of the front façade. The home takes advantage of its Southern exposure, using the reflector screen to funnel sunlight and warmth deep into the interior space.

The Lai family—Mayuko, baby Shota on her lap, David, Maya, and Yumi sitting on a cushion on the deck—relaxes in their indoor-outdoor living space, made by opening the glass sliding doors to connect the living room and engawa deck.

Karen White, David MacNaughtan, and their sons, Griffin and Finlay, hang out on the front deckof their narrow home in Toronto’s leafy Roncesvalles neighborhood. A narrow modernist composition of glass panes and purple brick, the house slips like a bookmark between two older buildings, a bright three-story abode on a lot narrower than most suburban driveways. Photo by Dean Kaufman. Read more about the small house here.

The most sustainable element of all is the Lais’ intention to make their first home their last home as well. “Some people have this mentality of getting a starter house, then upgrading from there,” David says. “We just wanted to find a place to live in and then stay there forever.” Eventually they imagine passing the home down to their children.

The majority of windows are on the south facade to optimize solar gain.

Active systems, in addition to thoughtful orientation and structural planning, help the structure become ultra efficient. The primary heating source throughout the house is radiant flooring connected to a geothermal system. Tedesco specified the Uponor Climate Control Network to operate the systems. "Every heating zone can be scheduled for setback," he says. "Then, through the communication and coordination of zone operation from main control panel that monitors the entire system, equipment and zones are cycled in harmony. The entire climate control system including the geothermal, ERV, A/C, and heat pumps is balanced to maintain optimal performance and occupant comfort. The Lutron Maestro lighting control, home entertainment, and security system can all be monitored and controlled remotely through a web-based program provided by the equipment supplier. The entire system has wireless access points throughout the house to ensure conductivity." The media room sofas are Ikea's Karlstad model, the rug is by Bev Hisey Textile Design, and the pendant is the Caprice by Viso.

Tedesco's father was a precision machinist and his uncles worked as welders and carpentry framers. As a tribute to his family's history, Tedesco made the blackened-steel-and-wood staircase a focal point—it can be seen from nearly every room in the house.

The Brick screen by Eileen Gray for Aram Designs blocks off a small office from the dining room.

Yang Yeo and his girlfriend Ching Ian relax on the back stoop of their renovated and radically updated Singapore shophouse—an archetypal building type in this busy port city. “Shophouses brought back memories of our childhood,” says Yeo.

What drew Seth Grosshandler and Kim Wainwright to their 20-acre property in rural Hillsdale, New York, were the extraordinary unobstructed views of the Berkshires to the east and the Catskills to the west. The challenge on the completely exposed hilltop site was protecting their planned 2,800-square-foot, two-bedroom courtyard house from the occasionally brutal weather.

Among the first Passive Houses in France, this bamboo-clad farmhouse by the Parisian firm Karawitz Architecture only uses a tenth of the energy a conventionally constructed home does. Photo by Nicholas Calcott.

Christine (at left), and Amanda (at right) chat with David’s sister Aroha Yates-Smith (center) in the kitchen.

The clients insisted that none of the trees on the property be disturbed, so Kevin Alter and his team at Alterstudio Architecture built a deck and an overhang around two of them.

Another view of the deck.

“The house is a piece of origami made out of triangular shapes, which we then draped over the landscape,” says Arbel.

Alterstudio Architecture of Austin designed this house in the Texas capital for a young family of four.

In consultation with the clients, Alterstudio opted to clad the house in local cypress rather than imported, FSC-certified ipe.

“Sustainability is very important to us,” lead architect Heather Dubbeldam says. “It is easy to design with passive systems, to use passive sustainable principles to influence the design and layout of the house.” Her team reduced the need for air conditioning and artificial lighting through carefully positioned doors and windows that draw in natural light and breeze. New insulation, low-flow plumbing fixtures, and low-energy lighting also minimize the homeowners’ dependence on utilities.

A deck is located off the dining area.

For now, one-year-old Awa is small enough to sleep in the hammock that hangs from the ceiling.

The structure has a 60/40 ratio of walls to windows, a figure that was achieved through computer modeling. "This ratio balances the amount of high R-value solid wall to glazing to create an overall building envelope for optimum thermal performance," Tedesco says. "This ratio was fine-tuned and tested using computer modeling that incorporated site-specific information such as building orientation, and the surrounding infrastructure such as neighboring houses and trees. The end result was an envelope design and window placement strategy that optimizes seasonal daylight cycles, maximizes solar gains in the winter, increases the level of interior natural daylighting, and considers views of the surrounding neighborhood." Because the residents are sensitive to noise, the walls feature extra insulaton, especially in the bedrooms and media rooms.

While the house is spread over two stories, Tedesco alotted space for an elevator, should the residents have mobility issues down the line. The pendants are Spillray by Axo and the windows are Loewen.

The kitchen features cabinets from Bulthaup’s B3 line and a hearth made of ironspot brick. Evans and his wife, Susan Wilson, bought the wall clock at Habitat in London.

“Often when we talk about sustainability we focus on the gadgetry, what makes things feasible off grid,” Moffitt says. “But to me there are more interesting things in passive design that rely on the available sun and wind.” An eight-panel solar array does chip in significantly, generating all the electricity the house needs.

Nix and Novak-Zemplinski designed the black-steel bookshelves and had them fabricated at a local metal shop.

Architect Tamira Sawatzky and artist Elle Flanders get an awfully good view of their busy Toronto street from their office and dining room.

The table is by Made, the sneaker-inspired Shoe Toss pendants are by Jeremy Hatch of Ricochet Studio, and the laser-cut photo on the wall is by the couple’s collective art and design practice, Public Studio.

Bruce Thatcher and Kirsty Leighton behind their London home.

Light illuminates the back of the home at night. The Vicenza flamed basalt exterior and floor-to-ceiling windows are a bold counterpoint to the house's more traditional neighbors.

The architects created the illusion of more space by opening up the floor plan, repositioning the staircase and introducing sight lines to the large windows on the south side. Recurring black accents—from the dining room’s Serge Mouille light fixture to its tall bookcases—contrast the brightness of the crisp white walls. Walnut floors and lighter wood furniture like the Klaus Willhelm table and Hans Wegner Wishbone chairs cozy up the home, while colorful objects animate it. “We strongly believe that people do not need more space, they just need better-designed space,” Dubbeldam says.

“I love the master bedroom, with the geometry of the white-painted, angled roof lines and the varying shadows that this creates,” Dubbeldam says. The naturally lit space features built-in shelves and a floating desk that overlooks the street below through a tiny window. An aluminum Eames task chair and a Serge Mouille wall light adorn the space.

The interiors of this 1850s threshing barn in rural England are finished in OSB. The material, usually used as sheathing under exterior cladding, reminded the project’s architect Carl Turner of the straw that was once held in the barn.

An Eames lounge and ottoman hold court in the master bedroom upstairs. Plenty of natural light and a muted color scheme give the space a wonderfully light feel.

Bassam (left, with Fellows) hung redwood garage doors that match the house’s exterior.

The flooring throughout the interior is maple. A vintage Ercol sofa and arm chair, Eclipse coffee table by Stua, Wide Wale rug by Bev Hisey Textile Design, and Moon floor lamp by Estiluz Spain furnish the living room. "Extensive planning went into ‘aging in place’ forecasting a host of different scenarios about what that meant physically and psychologically," architect Alex Tedesco says. "We did ‘day in the life’ modeling to understand all the various barrier free requirements that might arise."

Angela Brooks and son Calder revel in the benefits of free solar energy, cheerfully opening the living room’s big glass doors when it’s time to play.