Once we concluded that the entire corner of the house would be a glass curtain wall, we debated what room should go above the kitchen to take advantage of the light” says Stelle. “It ended up being the master bath because it's the one room you never want to be dark.” The glass has a mild reflective coating that makes it difficult to see in during the day, and meter-high sand-blasted panels ensure privacy after dark and below the neck. Operable awning windows above the opacity line capture cool breezes, which is key for meeting strict Swiss energy regulations.

Stelle took the idea of transparency one step further by keeping the requisite amount of “stuff you need to make a bathroom work” as unobtrusive as possible. This one had to have a bathtub, so he relegated it to the innermost wall. Opposite the tub is a barely detectable but fully enclosed steam shower made from ultra-translucent, frameless glass walls. Only telltale door hardware and a granite bench reveal its location.

The master suite is enclosed by a sliding hall door that separates the bedroom, bathing area, powder room, and dressing rooms from the rest of the second floor.

The master suite is enclosed by a sliding hall door that separates the bedroom, bathing area, powder room, and dressing rooms from the rest of the second floor.

The husband's vanity occupies the other curtain wall because his accoutrements fit into a narrow cabinet atop a chrome tube. In the same minimalist vein, his mirror is attached to a telescoping arm and the thin steel legs of his vanity align with the glass wall's extrusions. The wife's requirements were more elaborate. “She's a professional singer, so makeup is a big deal,” Stelle says. Consequently, her vanity extends to the floor and runs the length of the second interior wall. No worries about her being in the dark, however, with a full-width mirror reflecting views and light. A clerestory above the mirror filters in additional natural light where it's needed most.”

architect: Stelle Architects, Bridgehampton, N.Y.; project team: Walter Enkleri, Kate Evarts, Stelle Architects; associate architect: Werner Fisler, Zurich, Switzerland. builder: Bauer & Company, Zurich; curtain wall consultants: Meba Tech, Zurich; lighting: Van Lynden Associates, Zurich.