Bringing the outside in is not always a primary concern in designing retail spaces. However, it was almost a prerequisite in the case of the latest Paris boutique for Zadig & Voltaire. Overlooking the breathtaking Église Saint-Sulpice, a nearly 400-year-old church that thronged with the curious for a short while after figuring in Dan Brown's The Da Vinci Code, this boutique on the Left Bank is literally a succession of rooms with a view.

"The location was important not only because of the church but also because this is the square where Yves Saint Laurent opened his first Rive Gauche store," Zadig & Voltaire founder and designer Thierry Gillier says. His boutique now occupies two stories of a building completed right around the time that the greatest philosophe of them all was writing his novel Zadig, ou la Destinée. "We originally had a small ground-level boutique there," Gillier explains. "When the upstairs became available, it was a question of finding the right vocabulary to tell a story using the whole space."

Isabelle Stanislas, who cofounded the architecture firm So-An with Leiko Oshima in 2001, knows that story by heart. She's worked with Gillier on dozens of boutiques for the label, which targets hipsters looking for relaxed urban fashions with a rock-and-roll accent. Between stores in Saint-Tropez, London, Tokyo, and elsewhere, she's spent much of the past few years on planes.

For the 5,400-square-foot Place Saint-Sulpice project, she sought to evoke a typical Parisian apartment—oak floors, tall divided-light windows. "Thierry thinks like an architect," she notes. "He came at the project saying, 'Luxury is space.'"

She transformed most of the ground level into an entry. To the right, a flight of floating limestone steps ascends to a rather sober landing. It's empty except for a sculptural white desk uncluttered by cash registers—they're kept low and out of sight.

Customers walk past to reach the main sales floor, where the street-front rooms flow one into the other in succession, like the living spaces of an apartment. Each room is dedicated to a different type of merchandise: men's, women's, children's. Adding to the residential feel are tables topped by slabs of sanded, stained oak and modern seating that includes a pair of Finnish 1950's armchairs in steel and leather, hunted down at the flea market.

A hallway divides these exterior rooms from a large skylit area presenting everything from slouchy leather bags to the V-neck T-shirts that are among the label's signature items. To display and store the merchandise, Stanislas designed angular white-lacquered islands. Concrete flooring keep the backdrop neutral.

Throughout, Stanislas emphasized simple materials and natural luminosity. "We didn't touch the windows," she says. "And I surrounded the whole volume with the small, inset oval fixtures that are used to illuminate the bridges in Paris."

Sculpting the ceiling contributed to the residential ambience. Stanislas lowered the ceiling 3 inches over the central hallway in order to accommodate lighting as well as to reduce the potentially cavernous feel of the interior.

Alongside the staircase, flat screens flash video images of Zadig & Voltaire's key references: electric guitars, motor cycles, and other riffs on a 1960's theme. Black-and-white photomurals, blowups from a print-ad campaign, wrap a structural column and line a corridor. "The images represent Thierry's world," Stanislas says. "They're like photos a family puts on the wall." Just in case that message doesn't come through loud and clear, she parked a customized Triumph motorcycle right in the front window. —Nadine Frey

From left: Slabs of lacquered MDF stack up to form the custom cash-wrap desk at a Zadig & Voltaire boutique. The desk sits at the top of a flight of limestone steps from the ground-level entry.

Clockwise from top left: The two-story building dates to the 18th century. Track lighting runs the 26-foot length of an existing skylight. A textured shoe reflects a splash of color. Six flatscreens ascend with the stairwell. In a front room, a display fixture combines a sanded, stained oak top, acrylic shelving, and a mirrored base. This structural column flaunts a printed-vinyl photomural of an easy rider from the label's ad campaign.

From top: Photomurals also alternate with windows. A custom-detailed Triumph motorcycle poses in the front window.

THROUGHOUT MODULAR LIGHTING INSTRUMENTS: LINEAR FIXTURES. AGABEKOV: RECESSED CEILING FIXTURES. ERCO: TRACK LIGHTING. RAYMOND AU-PRETRE: STRUCTURAL ENGINEER. AU GRÉ DU VERRE: GLASSWORK. AMB: CUSTOM DISPLAY FIXTURES. RDM: GENERAL CONTRACTOR.