The master bathroom in this Boston loft serves all the standard functions of a custom bath, furnishing its owners with a spacious, comfortable place to prepare for the day and get ready for bed. But it also has an alternate purpose. Long, narrow windows cut into one of its walls look out over the loft's main, 18-foot-tall living space. At night, the bath becomes a source of ambient light for that room. “The window slits become glowing objects,” explains architect Brad Walker. “The bath acts as a light fixture for the rest of the loft.”

The effect is heightened by a frosted-glass shower wall that looks out over the kitchen. Walker left a strip of the glass unfrosted so that the owners can see across the loft, out to the terrace, while showering. And he installed a slot skylight above that wall. During the day, the sun's rays bounce off the frosted glass to create a soft luminosity. Artificial light from inside the loft produces a similar result in the evening. The bath's lights can be controlled from a dimmer switch in the kitchen, enabling the owners to change the mood of the entire home with one move.

The interior of the bath adheres to the loft ideal of openness. Two fixed-glass panels keep water from escaping the shower; the space between them serves as the shower's entry. Since the owners prefer showers to baths, there was no need for a tub. Instead, the shower received generous doses of space and budget, with its two shower-heads and enclosure of white Carrara marble and honed limestone.

Project Credits: Builder: SeaDar Enterprises, Boston; Architect: Ruhl Walker Architects, Boston; Project size: 95 square feet; Construction cost: Withheld; Photographer: Glenn Daidone.

Resources: Faucets: Vola, Circle 434; Lavatories, showerheads, shower valves, and toilet: Kohler, Circle 435; Lighting: Flos USA, Circle 436.