Sreed Ebisu T Office Building

Sreed Ebisu T Office Building

Sreed Ebisu T Office Building is a nine-story hybrid timber-steel office structure located in the Ebisu district of Shibuya-ward, Tokyo, representing an innovative approach to urban timber architecture that emerged from the design challenges posed by the COVID-19 pandemic and the subsequent reevaluation of workplace environments. Conceived during a period when remote work technologies were rapidly advancing and the necessity of physical office spaces was being questioned, this architectural project sought to redefine the value proposition of urban workspaces by integrating the warmth and tactile qualities of timber construction with the structural efficiency of steel framing. The building employs a distinctive hybrid structural system that combines a steel post-and-beam frame with what the design team termed seismic timber lattice shells, which are timber seismic frames inserted into the steel structure to serve dual functions as both structural bracing elements and exposed interior features. This innovative structural approach addresses one of the fundamental challenges in urban timber construction: the need to satisfy stringent fire resistance requirements while maintaining the aesthetic and spatial qualities inherent to timber architecture. By utilizing timber elements specifically as seismic bracing components, the design circumvents the typical fireproofing requirements that would otherwise necessitate concealing the timber behind protective layers, as structural members that function solely to resist seismic forces are exempt from certain fire-resistance regulations under Japanese building codes. The building rises to a height of 34.3 meters with a total floor area of 564.7 square meters and a compact footprint of 80.0 square meters, accommodating restaurant or retail functions on the ground and first floors while dedicating the third through ninth floors to office spaces. The architectural program includes legally mandated evacuation staircases and balconies on each floor, along with elevator access, all while maintaining compliance with fireproof building standards as stipulated by the Building Standards Act of Japan. The design philosophy underlying Sreed Ebisu T Office Building reflects a conscious effort to create a new typology within the emerging field of urban timber architecture in Japan, which has experienced significant growth in recent years but has largely been characterized by multi-story post-and-beam timber structures that, while technically innovative in their acquisition of special fire-resistance certifications, essentially replicate the spatial characteristics of reinforced concrete or steel-frame construction without fully exploiting the unique spatial and experiential qualities that timber construction can offer. In contrast, this project prioritizes the creation of intimate, enveloping workspaces where the exposed timber lattice shells provide visual warmth and tactile richness, fostering work environments that combine the comfort associated with residential spaces with the collaborative advantages of shared professional settings. Beyond the individual floor plates, the building incorporates a carefully considered circulation strategy that transforms the required evacuation staircase from a purely utilitarian element into an activated social infrastructure, functioning as the primary daily circulation route and connecting a series of common terraces distributed throughout the building's vertical section. These outdoor terraces serve as informal gathering spaces that encourage spontaneous interactions among workers from different tenant companies, thereby facilitating cross-pollination of ideas and collaborative opportunities that extend beyond the boundaries of individual organizations. The technical realization of this unprecedented construction methodology required extensive coordination among a specialized team comprising the contractor, a steel fabricator, and a timber fabricator, with particular attention devoted to the detailed design of the steel-timber joints, which represented a novel connection typology without established precedents in Japanese construction practice. The design and construction team utilized three-dimensional digital modeling to develop and refine these connection details, while simultaneously addressing the inherent differences in fabrication tolerances between steel and timber components, necessitating rigorous accuracy management protocols during the on-site assembly process. The project timeline extended from June 2020 to January 2023, encompassing a one-year design phase followed by an approximately nineteen-month construction period, after which the building was immediately occupied and has since achieved full tenancy across all available floors. The conceptual framework for Sreed Ebisu T Office Building engages with two primary motivations driving contemporary timber construction in Japan: the reduction of carbon dioxide emissions associated with building construction and the utilization of the nation's substantial forest resources, which have accumulated due to decades of forestry management practices. The design team's research into structural methodologies for urban timber buildings identified fire resistance and structural strength as the principal technical obstacles, leading to the development of the seismic timber lattice shell system as a solution that satisfies structural performance requirements while remaining visibly exposed within the interior environment. This architectural work was designed by Salhaus, a Tokyo-based architecture firm co-founded by Motoki Yasuhara, Masashi Hino, and Mari Tochizawa, with structural engineering contributions from Jun Sato, and was commissioned by Sapporo Real Estate Co., Ltd. The innovative integration of timber and steel structural systems, the reconceptualization of workplace environments in response to evolving work patterns, and the successful navigation of complex regulatory requirements for urban timber construction culminated in Sreed Ebisu T Office Building receiving the Silver A' Design Award in the Architecture, Building and Structure Design category in 2025, one of the world's most prestigious design competitions. The Silver A' Design Award designation recognizes designs that demonstrate exceptional excellence and innovation, acknowledging creations that are both aesthetically compelling and highly functional while reflecting deep understanding and skill on the part of their designers, with recipients recognized for their contributions to raising industry standards and advancing design practice through work that incorporates original innovations and elicits strong emotional responses, ultimately making notable impacts on the improvement of everyday life. The award jury evaluated entries based on criteria including innovative use of space, structural integrity, aesthetic appeal, environmental impact, functional efficiency, material selection, technological integration, social relevance, cultural sensitivity, economic viability, design originality, user comfort, energy efficiency, adaptability to change, use of natural light, spatial harmony, safety measures, accessibility considerations, resilience to weather, and integration with surroundings, recognizing Sreed Ebisu T Office Building as a tremendously brilliant and exceedingly creative work that illustrates outstanding expertise, talent, and acuity in addressing the complex challenges of contemporary urban architecture while pioneering new possibilities for timber construction in dense metropolitan contexts.

Architecture, Building and Structure Design, Urban Timber Construction, Hybrid Structural Systems, Seismic Timber Lattice Shell, Workplace Design Innovation, Sustainable Office Buildings

— Adam Dawson