XTEN Architecture is an award-winning architecture firm based in Los Angeles, California and Sissach, Switzerland. Founded in 2000 by partners Monika Hfelfinger SIA and Austin Kelly AIA, XTEN Architecture is a full service architecture and design firm specializing in custom residential, cultural, institutional and commercial buildings. Architectural designs are developed using innovative materials, advanced structural strategies, sustainable technologies, and guided from schematic design through the successful completion of construction. XTEN approaches architecture with an emphasis on strategic planning, open spatial configurations, refined material detailing and the highest level of craftsmanship. Through research and analysis, the architects distill the parameters of site, structure, project brief and resources into strong sculptural forms at the scale of the landscape. The interior-exterior spaces created open to and are completely transformed by direct connections to nature and the buildings' immediate environment. XTEN Architecture has received numerous architectural awards, including several International Architecture Awards from the Chicago Athenaeum/ European Centre for Architecture, the National AIA Housing Award, several American Architecture Awards, AIA California Council Architecture Awards, the IV Miami+Design Bienal Architecture Award, the Los Angeles Architecture Award, the Bloomberg Luxury Property Award, Custom Home of the Year Award and a number of awards from the Los Angeles American Institute of Architects. The work of XTEN Architecture has been has been exhibited in the US and Europe and published extensively, appearing on the covers of Architectural Record, Architectural Digest, Elle Décor, Architectur und Wohnen and in the New York Times, The Los Angeles Times, Wallpaper, MARK, Architectural Record, Interior Design, Angeleno, LA Architect, FORM, Interni/ Russia, Times Space/ China, IW/ China, DETAIL/ Korea, IDS/ Korea, Spa De/Japan, Belle/ Australia, Disenart/ Spain, REM/ Portugal, AD ...
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The XTEN Architecture annual revenue was $13.1 million in 2026.
Monika Haefelfinger is the President of XTEN Architecture.
5 people are employed at XTEN Architecture.
XTEN Architecture is based in Culver City, California.
The NAICS codes for XTEN Architecture are [5413, 541, 54, 54131].
The SIC codes for XTEN Architecture are [87, 871].