About Us

frenchCALIFORNIA is a New York– and California–based design studio creating timeless, globally inspired interiors.

Our Philosophy

ELEVATED DESIGN & AESTHETICS

Founded by Paris-born designer Guillaume Coutheillas, the studio specializes in luxury residential design, including turnkey renovations, interior furnishings, art curation, and model residence staging, while also taking on select commercial and exhibition projects.

A GLOBAL APPROACH

Over the past decade, frenchCALIFORNIA has contributed design expertise to projects developed in collaboration with internationally acclaimed architecture firms such as Sir David Adjaye, Robert A.M. Stern Architects, Rogers Stirk Harbour + Partners, Richard Meier & Partners, and Foster + Partners.

What We Offer

We believe in creating beautiful homes that capture your style. With a strong attention to detail, our Architectural-Digest-approved team will create a space that feels like home.
We work with builders, brokers, and homeowners and know how important it is to sell a home. Our award-winning team will make sure your space is more than just a property. We will make it a destination.
Turnkey service from purchasing to installation. Working with artists and gallery owners across the world, we find unique pieces that bring your space to the next level.
We support you by providing the research necessary to shorten time on the market and ask a competitive price.
Looking to create a brand for your condominium, multifamily property or hospitality project? Our creative team specializes in bringing your ideas to life through branding and activation.
Our creative team works with brands to find their identity and design pieces that highlight their individuality and uniqueness.

Learn More

Guillaume Coutheillas, Paris-born interior designer and founder of frenchCALIFORNIA studio for commercial and residential interiors

ABOUT THE FOUNDER

Interior designer Guillaume Coutheillas is the founder of frenchCALIFORNIA, a globally minded interior design and branding studio creating highly personal residential and commercial interiors shaped by architecture, art and collectible design.

Born and raised on Paris's Left Bank in a family of art lovers, Coutheillas developed an early fascination with the emotional power of objects and the ways interiors can express history, identity and culture. Today, his work is defined by a deeply layered approach that combines French refinement with an American sense of openness, creating spaces that feel both timeless and profoundly personal.

Early in his career, Coutheillas developed his design philosophy while reimagining the model residences of some of New York's most ambitious residential developments, collaborating alongside internationally acclaimed architectural firms including Robert A.M. Stern Architects, Richard Meier & Partners, and Foster + Partners. Working at the intersection of architecture, real estate and design gave him a unique understanding of how people emotionally connect with space—an approach that continues to inform every aspect of frenchCALIFORNIA's work today.

Through frenchCALIFORNIA, Coutheillas creates residences, hospitality projects, commercial environments and model residences united by a singular point of view: interiors where architecture, art, antiques, contemporary design and meaningful objects come together to tell deeply personal stories. Alongside the studio's design practice, frenchCALIFORNIA also curates a collection of antiques, vintage pieces, and contemporary works, reflecting the belief that exceptional interiors are built through thoughtful collecting as much as thoughtful design.

The studio's work has been featured in Architectural Digest, Interior Design Magazine, Galerie, Robb Report, and other leading publications, and has received recognition from the Interior Design Society of America, NYCxDESIGN Awards, and The Architect's Newspaper. Coutheillas is actively involved in the international design community through organizations including the Urban Land Institute, the Interior Design Society, the Designer Society of America, and by supporting institutions such as SFMOMA and the de Young Museum.