The ground-floor sauna, one of the home’s central gathering spots, is built from stained alder. The electric heater is from the Finnish company Iki.

The exterior is clad in Siberian larch, which doesn’t require paint and will develop a gray patina.

The kitchen is outfitted with a built-in refrigerator by Norcool and an AEG cooktop and oven.

Salminen built the bunk beds out of birch, Finland’s most plentiful tree species, for the couple’s children.

The lower floor houses a spa, gym, and office. A built-in bathroom by Espace Cuisine includes a sauna.

Resident Peter Østergaard (with Maja, 6, and Carl, 20 months) and architect and photographer Jonas Bjerre-Poulsen have been best friends since they were 13, which makes for easy collaboration. Says Bjerre-Poulsen: “There are always a lot of challenges in a renovation, but Peter and Åsa trusted my judgment and gave me a completely free hand. Usually it’s hard to push people into unconventional solutions, but Peter has all these wild and crazy ideas.” One such idea was to embed a transparent glass-and-iron door in the floor, operated by a hydraulic pump, which allows access to the subterranean wine cellar. At night, the lit-up cellar glows, lending the compact living room an increased sense of verticality.

A collection of vintage furniture, including a rattan armchair and a drafting table, is gathered around the terrace fireplace, which shares a volume with the hearth in the adjacent living room behind. Outdoor sconces are from iGuzzini.

The sauna is a decidedly Scandinavian touch.

This dreamy, glass bedroom by the lake was created as an early prototype for the prefabricated greenhouse/she kits known as the Kekkilä Green Sheds.

Helsinki architect Ville Hara and designer Linda Bergroth collaborated on a prefab shed-meets-sleeping cabin, which can be assembled with little else than a screwdriver. Bergroth, inspired by nomadic yurt dwellers, wanted an indoor/outdoor experience for her property in Finland.

Black and white kitchen cabinets painted with a triangular pattern add a whimsical touch to this funky kitchen.

House M-M Floor Plan

A converted attic in a turn-of-the-century building in Berlin’s Charlottenburg neighborhood asks over $4 million. If you’re looking for a modern retreat in an old-world setting, cast your sights on this charming loft in the west Berlin neighborhood of Charlottenburg, known for its distinguished selection of shopping, dining, theaters, and museums.

Salminen chose flame birch for the cabinetry for its remarkable wavy wood grain.

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.

Homeowner Susanna prefers a motley set of dining chairs over a coordinated set; that way, guests can pick their favorite when they sit. Photo by: Petra Bindel

The bookshelves lining the walls of the living room were inherited from family.

The home also features an elegant sauna—this is Finland after all.

The wood shed portion artfully encapsulates all the domestic detritus that would be anathema within the all-glass sleeping portion.

The flooring and stair risers are European ash, treated with a varnish that was tinted one percent white.

The home includes a traditional Finnish sauna clad in birch.

A sauna is an optional feature. Cedar and concrete create a recurring visual theme from the exterior to the interior.

Achieving such efficiency and maintaining the integrity of the wetlands and woodlands on the property meant more research for both the designers and the resident—just getting approval for the siting of the buildings and the driveway took eight months—but Hague is hardly one to do things half way. “A lot of times couples engage in house-building, like birds. I'm doing this solo, more like a monk,” he says of the deeply personal undertaking.

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.

The 1968 house’s shape—a rounded triangle topped with a sweeping concrete roofline that suggests a helmet as it rises above huge banks of windows—lends itself totally to Kukkapuro’s philosophy. “It is a structure in waiting, prone to change as the landscape around it—not yet a form, rather a possibility,” he says. “It changes in harmony with the seasons and the moods of its inhabitants.”

Bicycle Sauna, H3T Architects, 2011 Equipped with the necessary hookups to tow behind a tandem bike, this richshaw-like contraption is a sauna that, amazingly, can fit six. Heat is generated by an internal fireplace and trapped by the polycarbonate hood.

A sofa from Design Within Reach opposes a Hi Turn chair by Bensen in the living room.

The woodburning sauna stove is made by a Finnish company, IKI.

Here's what you need to know before undergoing a building project with a contractor but no architect.

Street Smarts-An artist and designer couple transform an old Toronto storefront in Dundas West into a home and studio. Their industrial yet cozy abode mixes customized Ikea pieces with art by up-and-coming designers and modern finds. Photo by: Naomi Finlay

Sheridan Coakley, owner of the London-based furnishings purveyor SCP, uses his circa-1970s home as a testing ground for the furnishings he carries in his company’s inventory. In the foreground, a Balzac lounge chair by Matthew Hilton is draped with a Donna Wilson blanket.

When not in use during winter, the tub is hidden from the home’s view. The entrance has a sheltered overhang for car parking.

In keeping with Hayon’s goal of creating a serene and airy home, the master bedroom and sticks to a mostly neutral palette of whites and grays. The bench by the bed is a custom piece designed by Hayon and Klunder and fabricated by their carpenter friend Josep Joffre.

An upstairs bedroom is at once bright and cozy.

The Carlos Scarpa chandelier and dining chairs by Werner West are both family heirlooms; the table is another custom design by Salminen.

A completed clan.