Ethan Schussler built his first tree house at 12 years old. His tree house in Sandpoint, Idaho, sits 30 feet above the ground and can be accessed by an "elevator" consisting of a bicycle that, when pedaled, ascends a pulley system to the top.

Purple thistles, California poppies, clover, and dandelions have all taken root in the roughly 10-inch-deep, lightweight humus and grape-husk soil in this 580-square-foot green roof. Designer Peter Liang says that he "wanted to plant a green roof for its thermal mass, but I wanted it to be as natural as possible."

Suzanne and Brooks Kelley at the back of their 1,100-square-foot guest cottage.

The owners toured this home, which surrounds a mature tipu tipu tree, while visiting relatives for the day. The brick is original to the 1947 construction.

Airstream’s Flying Cloud 30FB Office travel trailer includes a designated workspace in the back corner.

Sliding doors by Quantum were made to look like the original panes that couldn't be saved, and they lead to a fire pit outside.

At the top of the stairwell, a sitting area is outfitted with a vintage Eames lounge, a large Jack Goldstein painting, and a 1970s light fixture found by Marcovitz in Paris.

The view!

The design team restored the existing wood beams, giving nod to the home’s former rustic life, while introducing big windows, white walls, and clean lines.

The kitchen features a concrete island topped with marble. Deja-Vu stools by Naoto Fukasawa surround the island. A print by Guy Gormley, as well as a painting bought during holiday in St. Tropez, hang on the walls.

Bay Point Landing offers cabin and Airstream accommodations, RV sites, a communal clubhouse, an indoor saltwater pool, an event hall, a private beach—and plenty of open spaces for surfing, whale watching, crabbing, fishing, or hiking.

A pair of environmentally attuned architects combined adjoining properties in a Los Angeles canyon to house their modernist menagerie. With exposed industrial materials for finishes, the interior includes hand-troweled, waxed concrete floors, Douglas fir beams, and sealed-plywood ceilings. The open kitchen’s island, topped with soapstone, doubles as a bookcase for the living room.

The upper floor of one of the cabins features a wood-burning stove, beanbag chairs, and a hanging paper lantern.

Take a look at some of the most exciting, sustainable buildings around the world, and you may notice something they have in common: green roofs, or rooftops covered with a thin layer of soil to allow for grasses and other low-lying plants to grow.

New Depths Inspired by a local winery, George Kyprianou wanted a glass top on his subterranean wine cellar. The interior is lit, casting soft light into the living space at night and revealing the 132-year-old stone foundation. The three-quarter-inch glass lid sits flush with the floorboards; it opens with an ingenious device that Kyprianou devised using a 12-volt air compressor and a remote-controlled switch. When you push the button, the glass lifts just enough to be removed by hand.

Light Box Peter created a simple uplight at the top of the wood box by wiring together energy-efficient fluorescent fixtures typically used under cabinets and countertops. “The cheaper magnetic models hum unacceptably loudly, so make sure you get the electronic ballast types,” he warns. He then painted the cavity white to reflect light and covered them with quarter-inch-thick acrylic from TAP Plastics. homedepot.com tapplastics.com

The view of Kapiti Island is fully revealed from the tower.

“A building can have far greater impact than the space it stands in.”—William Carpenter, architect and resident

The Jorgensen's Menlo Park home is a model of green design with features that are smart for everyone to consider. "Every project is different, but there are some universal things that will apply from project to project," says Feldman about designing a green home. "The first—and most obvious thing—is to always try to build less, to have a smaller house and be smart about how the rooms are designed and oriented so that you can get by with less space. Smart design will lead to a smaller building, but it won't feel smaller."

New zoning allowed for a zero-lot-line structure, but required a public storefront, which Carpenter uses as an art gallery.

The top container contains Wardell's office—and a "napping nook" above that.

The backyard evokes the serenity of a Japanese Zen garden with a beautiful leaning tree and a shou sugi ban shed.

In the dining area, a one-of-a-kind table with a reclaimed Carrara marble top by NET—themultidisciplinary design firm of architect Alejandro Sticotti, with whom Nicolas works—is surrounded by prototypes of the company’s Board chair. The family dog, China, sits on a floor made of travertine tiles.

The Kelleys furnished the cottage with help from Suzanne’s daughter Betsy Burbank of Betsy Burbank Interiors. Classic modernist icons, such as a Saarinen Womb chair for Knoll, a Herman Miller Eames lounge chair, and an Eileen Grey E1027 side table look at home alongside present-day pieces such as an Encore sofa (which handily folds down into a sleeping surface) from Room & Board and a Doka rug designed and produced by Stephanie Odegard. The Wohlert pendant lights from Louis Poulsen were designed by Vilhelm Wohlert in 1959, but grouped as such, they appear distinctly contemporary.

The architects added a small circular skylight to serve as a vertical focal point in the center of the fifth floor. The quarter-sawn white oak risers produce a beautiful rippled grain highlighted by the abundant natural light.

Rian and Melissa Jorgensen's 2 Bar House in Menlo Park boasts all the usual green design suspects: energy-efficient lighting, good insulation, renewable material finishes, radiant heat, and the roof is pre-wired for future PV panels. Executed by Feldman Architecture, the house requires only natural lighting during the day which keeps energy costs way down. Still, the most stunning aspect of the green design is the living roof planted with succulents, aloe, viviums, and ice plants. "I'm absolutely glad that we did it," says Melissa. "It turned out so well and I really enjoy sitting up there and taking advantage of it as much as I can. It's very peaceful." Read more about this total remodel here.

The countertops in the kitchen are a mix of quartz surfaces and custom and salvaged stainless steel. "We use the kitchen all of the time, it turned out really nice," says Melissa. "It's very open, certainly one of the central focuses of the house, and is fun for entertaining."

The living room, dining room and kitchen are in one open space. The flooring is bamboo. The cabinetry is a mix of bamboo, walnut, and maple, and was fabricated by City Cabinetmakers out of San Francisco.

A couple enlist Butler Armsden Architects and Leverone Design to reimagine their home as a multigenerational meeting point. In 1963, landscape designer Lawrence Halprin devised a master plan for a community that would live in harmony with the natural environment. The resulting Sea Ranch, which stretches 10 miles along the Pacific coastline in Sonoma County, California, is characterized by timber-frame, wood-clad structures that are in dialogue with the local climate and terrain. Sited on a bluff within this pioneering community is the vacation home of a lawyer couple. After purchasing the residence in 2007, they lived in the home as it was for four years, even keeping the previous owners’ furniture. Envisioning a retreat that would accommodate their extended family and guests, they then recruited Butler Armsden Architects and Leverone Design to help guide the project.

For a cost-conscious 2,000-square-foot renovation located 30 minutes outside of Austin, Texas, architect Nick Deaver took a look around for inspiration. He spied galvanized metal cladding on the region’s sheds and co-opted the inexpensive, resilient material for his own design.

Yvette, Adrian, and their son Julian survey the view from the top-floor terrace. “I’ve never been fond of modernism—I find it cold,” Adrian admits. “But having this house, I have to say, it’s growing on me.”