Andre and Lisa Radandt turned a 1940s stone dwelling into guest lodgings for their Michigan home. They worked with architect-designers Gregory Dufner and Daniel Heighes Wismer, of the New York firm Dufner Heighes, who played to the building's strengths, retaining even its moss-covered roof.

A faux-bois cement table and chairs overlooking Lake Michigan blend in naturally with tree trunks and branches.

The cottage, designed by Earl Young, relies heavily on stone quarried in northern Michigan. The Radandts restored the distinctive fence and added new ones close to the house as a way of extending the architecture into the landscape.

Inspired by the existing stone fences, this wall -- installed by the architects, Gregory Dufner and Daniel Heighes Wismer, along the driveway -- is more than a decoration. It also encloses a planter in the front yard.

The fence was among the original features that the homeowners restored. Made from local stone, it highlights the natural edge of the bluff over Lake Michigan.

The visual themes of the exterior continue in the living room, above, with its rough-hewn fireplace and radiating ceiling. Dufner and Wismer added a stone floor and, for even greater texture, a diamond-patterned rug.

One of the few changes the architects made to Young's facade was replacing old outdoor fixtures with handsome metal sconces. There is no mechanical equipment visible outside the house because heating and cooling are facilitated by six geothermal wells under the lawn. The goal was to be green and avoid having unsightly air-conditioning units in the pastoral setting.

Overhead, the architects replaced the ceiling -- an odd Earl Young experiment consisting of plastic panels and neon lights -- with a wooden one of the same design. The furniture is classic but casual: a Jean-Michel Frank sofa, easy chairs by Jens Risom, and a coffee table of richly veined marble (designed by the architects). Among the more offbeat items added to the mix are a table with a fish-shaped base found on eBay and a spiral wooden side table.

Leggy furniture balances the house's heavy masonry. In one corner of the living room, a pair of Eero Saarinen womb chairs sidle up to an open Swedish bentwood bookcase.

In the master bedroom, a Lee Jofa curtain fabric inspired the color scheme, reflected in the silk-shag area rug and leather seating. As in the living room, Dufner and Wismer chose a combination of new and old furniture; the contemporary chaise, for instance, is based on early-twentieth-century Wiener Werkstatte designs. And they used earthy materials -- bronze, leather, rattan, walnut, and marble -- which, Dufner says, "looked right since the house seems to have literally grown out of the landscape." The Thomas O'Brien lamp is from Circa, one of the designers' favorite lighting sources.

The master bedroom is lined with textured grass cloth wallpaper. The Thomas O'Brien sconce is from circalighting.com.

The open kitchen shelves, made of cerused white oak, display decorative curios. A green Brunschwig & Fils wallpaper creates a bright and surprising backdrop. The trestle table allows legs to slide in easily along the banquette.

The Radandts loved the clawfoot tub from Waterworks in their own bathroom and wanted guests to enjoy one, too. An elegant Oly Studio side table and floor lamp from Circa encourage long, luxurious soaks.

Light-on-its feet furniture serves as a counterpoint to the house's heavy masonry. The writing table and elbow chair, by Hans Wegner, and 1920s Swedish lamp, have thin silhouettes.

Warm hues and appealing textures predominate in the bedroom. The walnut bed is from New York City furniture store BDDW, the linens are by Calvin Klein, and the night table is from McGuire.

Wooden pieces, such as the Hans Wegner chairs and the dining table (from BDDW), provide a warm contrast to the house's cool stone floor.

Lowering the floor inside the house produced a sunken patio out back; mahogany furniture by Chris Lehrecke for Pucci makes it a perfect outdoor living room.

The polished-nickel City Mirror from Urban Archeology is simple yet elegant; the olive Brunschwig & Fils Teawood wall covering adds drama to the small bathroom.

Old and new come together: The bed is vintage Tommi Parzinger, flanked by custom oak end tables with lacquered drawers. The Gooseneck Gourd Lamp is by Christopher Spitzmiller, and the bedding is from John Robshaw.

A swing-arm reading lamp spotlights a sculpture in a corner of the living room.