This revamped Montreal flat includes a rooftop sauna lined with torrified, or dried, cedar. Outfitted with glass paneling and oriented to capture views of Mount Royal, it is the ideal haven for this hardworking homeowner.

Jacobs transformed the roof into a series of decks, this deck features Crate & Barrel’s Dune sofa and coffee table.

To most eyes, Ezequiel Farca’s 1970s-style concrete home in Mexico City looked like a teardown. Even the lot itself—shallow and crammed against a steep hillside—wasn’t particularly alluring. But Farca saw through all the restraints to create a spa-like refuge in one of the world’s most energetic cities. "It’s is such a hectic place. You’re bombarded by so much information the moment you step into the streets," says Farca, who first gained prominence as a furniture and interior designer. "So we envisioned this house as a retreat, a kind of a temple." The rooftop courtyard is lined with a verdant mix of indigenous plants, including banana trees, palm trees, lion’s claw, Mexican breadfruit, and native vines. The chaise longues were designed for Farca’s EF Collection.

Villa Bio is situated a little over an hour outside of Barcelona in Llers, a green, hilly, sun-bathed sprawl near Figueres (hometown of everyone’s favorite mustachioed surrealist, Salvador Dali). The hydroponic rooftop garden grows out of volcanic stones. The home is conceived as a giant C-shaped spiral.

The entire cabin is powered by the rooftop solar system from Solarwinds Northernlights. "I still can't get over the fact that I can get an ice cube from the sun," Bruce says.

On the roof, Geller takes in the night sky with his telescope.

A 500-square-foot outdoor space with a grill, a table, and a hammock sits just off the entrance level of the townhouse, offering extra room for dining, relaxing, and entertaining. The corner couch is a custom piece inspired by the large cushions of Moroccan sofas. The Fermob table is paired with Hay Hee dining chairs by Hay.

Earning the nickname

Landscape architects Reed Hilderbrand helped fill out the completed prefab by planting sedge grass on one of the house’s two green roofs to reflect the texture of the surrounding meadow.

These no-fuss landscaping ideas yield gardens that practically take care of themselves.

The bright orange frame of this glazed door adds a sense of modern exuberance to the deck off of Francesco Moncada and Mafalda Rangel’s bedroom. The sunny, open space reveals both a Loop chair by Willy Guhl and the tile rooftops of Syracuse, where the water is never far off.

Rydingsvärd often cooks out on his terrace, which offers a view of Mount Royal. The volume housing the sauna is clad in cedar planks that were painted black. The door and windows are by Alumilex, and the custom outdoor shower is by Avantage Plus.

Atop the spiral staircase, a custom iron bench is festooned with Turkish throw pillows from SophiesBazaar.

Bob and Goya walk atop the guesthouse, which nestles into a hill.

Viewed from the roof, the home’s name—The Gables— makes perfect sense. Its asymmetric brick gables angle towards one another and converse with the architecture of the neighboring homes.

The rooftop garden planters were developed using computer software that eliminated the need for screws or glue. They hold an array of local plants and also funnel rainwater into a collection tank below.

From the grass roof patios, the house disappears almost completely, leaving only the landscape, water, and occasional passing orca.

A vast terrace overlooks a nearby park, while the ground floor patio (connected to Vanbesien’s office) opens up to a garden.

On the lower roof, cedar decking and flower beds define one of several outdoor gardening spaces. Part of her ongoing research into the livability of cities, Fitzgerald aimed to create landscaped areas that were “aesthetic, aromatic, educational, and productive.” The deck is bordered by an expanded aluminum mesh railing and black metal corrugated panels.

The deck is framed as an open-air room where the ceiling and walls have been peeled away. The grill is a vintage Weber Genesis 1000. LG solar panels from Pick My Solar contribute to the home’s net-zero energy profile, as does a moisture barrier in the walls that allows heat to escape.

The green roof is accessible via ladder. "This type of insertion on the plot demanded care and attention with the design of the rooftop, which is the fifth facade of the building," adds the architects.

Golden hour on the serene rooftop offers some of the city's finest views out onto the harbour below and far beyond.

The netting suspended over the water feature makes for a whimsical spot to stargaze.

The Sustainable L.A. Grand Challenge, a UCLA initiative with 150 faculty across 40 different departments, has the stated goal of bringing the L.A. region to 100% sustainability in water and energy while enhancing biodiversity by 2050.

A typical home uses somewhere around 150-200 therms of natural gas to heat water each year. With a solar system, usage is reduced to around 100 therms a year.

The terrace is a favorite gathering place. The house is positioned facing south to get the most sun exposure.

On the roof, Claudio and Aranza sit on salvaged blocks of wood around a “water mirror” that reflects the sky. On clear nights, you can gaze both up and down at the stars, an activity that gives Casa Cosmos its name.

The orderliness of the home’s structure contrasts with the wildness of the plantings that surround it.

The top floor holds two offices—one for the husband, the other for the wife. Hers opens out onto a small private deck furnished with wire Eames chairs.

"Our many ideas were floating around the mountain, and we needed someone to bring them down and turn them into reality,

The largest of multiple outdoor terraces includes a glass-mosaic-tile bench designed by Aldo Cibic and produced by Bisazza.