Cesar Rubio Photography

For a master suite addition to their home overlooking the San Francisco Bay, architect Cary Bernstein’s clients visualized a modern, spa-like retreat connected to the outdoors and immersed in nature. They honed in on four primal elements—earth, water, air, and fire—for the new space located on the eastern side of the single-story, mid-century modern house on a wooded 2-acre lot.

“The clients didn’t just want more square footage, but rather, a special kind of space that would feel deeply connected to their beautiful site and take advantage of their beautiful views,” says Bernstein.

The new master suite has a more voluminous scale, which contrasts with the existing home’s low ceilings and small doorways. At the entrance to the bath—which boasts 10-foot ceilings—a double-sided fireplace clad in French limestone that’s imprinted with insects, snails, leaves, and seashells, adds both the “earth” and “fire” elements to the room.

“The fireplace became an anchor point between the master bedroom and the master bath,” says Bernstein. “The natural character of the stone felt right against the strong geometry of the architecture.”

Flanking the fireplace, a pair of frosted glass panels, one fixed and the other functioning as the door, transmit light—the “air” element—from the bedroom into the bath. Natural light is also welcomed into the room with windows on three sides that invite shifting sunlight and shadow-play throughout the day. Sconces and recessed lighting with dropped glass rims softly illuminate the room at night.

Cesar Rubio Photography

Above one of the facing floating vanities, which are fitted with dark, espresso-colored counters and maple cabinetry, a large bronze-framed window captures the bay and nearby tree canopies, and reflects the view above the other vanity on a large mirror of the same size.

Each vanity was designed to the needs of each spouse. While one stretches the complete 16-foot width and includes open shelving space, the other has a built-in area for a small vanity stool. To facilitate a streamlined look, electrical outlets for grooming accessories are hidden in the cabinetry.

Thanks to the site’s sloping lot and densely clustered trees that ensure privacy, the design team was able to incorporate floor-to-ceiling windows in the shower and water closet areas to further open the space to the outdoors.

Embodying the “water” feature are two showers and a freestanding, white rectangular tub that sits in the center of the room surrounded by gray large-format porcelain tile, a material choice that supports the rest of the bathroom’s palette and complements the dark wood floors in the bedroom. The 4-foot-by-4-foot tile continues across the open walk-in shower space with two distinct sides—one fitted with a bench nook and a handheld shower, and the other with a standard showerhead and built-in niches. A linear drain runs between the showers, and a frosted glass curtain wall protrudes to add privacy from the bedroom.

Both walls in the shower area are outfitted from the floor to the ceiling with small-scale, ceramic tile with a blue-gray glaze. According to Bernstein, the perception of the tile’s hue shifts depending on the color of the sky.

To complete the room, Bernstein and the design team built the water closet on the other side of the standing shower with its own floor-to-ceiling window and a frosted glass entry.

“When you have a room with four distinct, active areas, controlling the palette so the space doesn’t seem too busy is important,” adds Bernstein. “The number of colors is minimal, but the textures help differentiate each material from the other.”