Los Angeles, California, USA
X2.5 by XTEN Architecture utilizes California Senate Bill 9 (SB9) to showcase an economical development strategy available to homeowners who were impacted by the recent fires. This strategy enables residents to remain and rebuild in the areas impacted by the fires. An additional benefit is provided to directly address California’s need to quickly provide additional housing. Splitting an R1 lot enables owners to either sell off half of their lot to fund their rebuild or utilize the second lot as an income property.
X2.5 won a Future House Award 2025 from The Chicago Athenaeum: Museum of Architecture and Design and Global Design News.
X2.5 won an American Architecture Award 2025 from The Chicago Athenaeum: Museum of Architecture and Design.
X2.5 reimagines the typical 50 x 130-foot lots, providing a robust housing model for high fire severity zones while safely increasing density. Utilizing the advancements in mass timber construction, X2.5 applies cross laminated timber (CLT) panels. This method offers much greater fire protection over typical type V construction. In addition, the CLT structural system creates a smaller carbon footprint than steel or concrete.
X2.5 inverses the typical relationship between living and sleeping spaces in a dynamic way by flipping the primary living spaces to the upper level. Contained under a series of sloping roofs and vaulted ceilings these spaces receive better views from the higher vantage point and additional light from clerestory windows. Additional deck space creates ‘outdoor rooms’, expanding the available living space. The bedrooms at the lower level open to private gardens.
X2.5 draws inspiration from the many mid-century modern and craftsman style homes that were lost to the fires. Exterior material choices and landscaping are selected to provide sustainable development with increased fire resistance.
The organization and structure of X2.5 is designed to be adaptable to various sites and conditions. Expressed as an exaggeration, the diagram is an array of options, formed in diverse shapes, conceived in various materials, and adapting to different orientations. This is NOT a literal development model for a neighborhood. This is an exaggeration to express the versatility of the system.
Architects: XTEN Architecture
Design Team: Monika Haefelfinger and Scott Utterstrom
General Contractor: XTEN Architecture
Client: Private
Photographs: Courtesy of the Architects
