When it came time to renovate this Paris apartment, a highly unconventional layout called for an unconventional design approach. The flat is located in a Haussmann apartment building, a historic 19th-century Parisian style named for designer Baron Georges Eugéne Haussmann. He designed and built the city’s current boulevards and uniform cream-colored limestone apartment buildings (featuring steep mansard roofs, wrought iron balconies, and up to six floors) as part of the modernization of Paris starting in 1859. Inside, these units typically have all the quintessential Parisian design details like high ceilings, ornate trim and moldings, double doors, and herringbone parquet wooden floors.

This particular apartment, called Gambetta after the street it’s on, features a layout running at an angle to the street-facing facade and rounded walls in the two main rooms, the kitchen/dining area, and the living room. So how exactly does one take an iconic Parisian apartment with this kind of unusual shape and modernize it for the 21st century — without losing its historic charm? Jean Benoît Vétillard Architecture decided to emphasize its curves, creating custom built-in furniture to amplify the preexisting theatrical character.

“The original plan is enlarged, and the lines of force are extended,” explain the architects. “The new composition is made of depths of field. So many backstage and stage spaces, more than serving spaces/served spaces. This new organization of domestic spaces is constructed by the punctual positioning of multifunctional furniture in oiled okoume wood and brushed aluminum.”

“The front of the kitchen table hides the access to the child’s bedroom, the bow window gives its shape to a modular tatami, the living room houses a large library, but also the parental bedroom, round by geometric mirror…the advantage of this design is that it does not alter the original structure, which remains unchanged. In their original material, the light of the Boulevard Gambetta, the white stucco, and the oak parquet floors have reappeared.”

The beauty of this renovation is that the architects have chosen to play up the apartment’s quirks and historic details rather than permanently eliminate or modify them. The brushed aluminum built-in bookcase that curves around the back wall of the living room contrasts with the all-white original trim around it, highlighting the geometries of the space. This material is seen again on the kitchen wall, where it’s joined by warm wooden tones that brighten up the room and complement the flooring.

The child’s bedroom, though small, is made functional thanks to a new built-in lofted bed above a series of built-in cabinets. The primary bedroom faces the back of the living room’s curved wall, now clad in the same wood as the kitchen cabinets. Most fun of all might just be the round modular seating in the living room, upholstered in a rich blue matching the adjacent curtains. It fits perfectly into the rounded nook beside the fireplace, its modern simplicity accented by the rusticity of the old wood floors. Overall, the design feels both mature and playful, contemporary and rooted in old Paris.