Project Name: House in Nakano

Location: Tokyo, Japan

Design Team: HOAA / Hiroyuki Oinuma Architect & Associates

Total Floor Area: 96.38 m²

Completion: 2025

Photography: Takuya Seki, Hiroyuki Oinuma

Design Features:

Project - House in Nakano, designed by HOAA / Hiroyuki Oinuma Architect & Associates, stands as an exemplary demonstration of design intelligence located in a densely populated residential area of Nakano, Tokyo. This two-storey wooden residence serves as the architect's own home, responding to the challenge of achieving the fundamental desire for "large windows facing a garden" under stringent urban conditions, creating a bright and transparent living space within a crowded metropolitan environment through innovative spatial strategies.

The project's most distinctive design feature lies in its innovative "aerial looping linear terrace" concept. Facing dual constraints of the site's north-facing road position and surrounding building obstructions, the architect conceived a linear terrace extending from the large second-floor window, looping through the air along the road boundary, named the "ornamental garden." This aerial structure actively seeks sunlight through gentle curves, skillfully avoiding the shadows cast by the building itself, introducing shimmering light variations to the dining room's north-facing window, and creating a unique transitional space between urban street and private residence. The ornamental garden not only resolves lighting challenges but becomes a medium connecting public realm and private life, enabling the individual residence to demonstrate an open public posture toward the city.

The architectural narrative unfolds through sophisticated spatial organization, fully utilizing the site's topographic conditions. The architect employs skip-floor design, leveraging site elevation differences to create multiple sightlines toward two gardens, forming a spiral circulation system traced in a single continuous line. This spatial sequence allows residents to alternately view the street-side ornamental garden and the rear garden at the site's depth, creating rich layers of spatial experience. The interior circulation is enveloped by carefully designed display shelving presenting objects, books, photographs, and plants of special significance to the owners, these life objects understood as representations of past living, endowing the residence with a refined atmosphere similar to a small museum while inspiring aspirations for future refined living.

Material selection reflects dual considerations of structural system and residential quality. The building employs traditional wooden post-and-beam construction, maintaining a warm and inviting residential atmosphere while satisfying structural performance. Realization of the ornamental garden depends on detailed consideration of structure, materials, and form, ensuring this aerial element possesses both visual lightness and capacity to withstand actual use demands. The building's overall material application demonstrates contemporary design refinement, pursuing high-quality spatial experience even under economic constraints.

The facade treatment demonstrates the contemporary significance of "ornamentation" as architectural element. The ornamental garden, as the facade's dominant element, differs from Art Nouveau or Postmodernism's application of decorative expression to the architectural body itself, instead creating psychological connections among people, dwelling, and city through "ornaments" including plants. When residents step from the second-floor door into the ornamental garden to water plants, they naturally engage in conversation with passing pedestrians, and children's laughter rings out. This design demonstrates new forms and roles for architectural ornamentation, adding color to urban residential life, making the individual residence a public instrument open to the city.

The project's defining feature lies in its creative response to urban residential dilemmas and spatial experiential value. House in Nakano is located in a typical Tokyo densely populated residential area where overlapping sightlines between adjacent residences are normal, and the site's north-facing road position makes obtaining sufficient natural light difficult relying solely on north-facing windows. Through the ornamental garden as an innovative element, the architect transforms disadvantageous conditions into design opportunities, creating a living space that satisfies privacy needs while filled with light. This is architecture designed to enhance everyday living quality, proving that under stringent urban conditions, architecture can create rich spatial experiences and emotional resonance through thoughtful design. Through the concept of "ornamentation," the building redefines the significance of decoration in contemporary urban residences, demonstrating the possibility of individual residences as urban public instruments, establishing refined and powerful dialogues between privacy and openness, between individual life and urban life.

Design Team - HOAA (Hiroyuki Oinuma Architect & Associates), founded in 2017 by Hiroyuki Oinuma and incorporated in 2019, is a Tokyo-based architectural practice committed to creating buildings that endure beyond trends and market fluctuations. Led by principal architect Hiroyuki Oinuma, a licensed first-class architect and registered real estate transaction agent, the firm operates from its studio in Nakano, Tokyo.

Oinuma brings substantial professional experience to the practice, having worked at Tadao Ando Architect & Associates from 2010 to 2015 and Nikken Housing System from 2015 to 2017. He graduated from the University of Tokyo's Department of Architecture in 2008 and completed his master's degree in architecture at the same institution in 2010. This rigorous academic foundation and exposure to internationally recognized architectural methodologies inform the firm's design approach.

The practice philosophy responds directly to contemporary architectural challenges in Japan, including population decline, rising construction costs, and the demand for economically viable investment properties. HOAA addresses these constraints through meticulous examination of details, materials, and formal strategies. The firm believes that careful consideration of each design element creates architecture capable of moving people emotionally and remaining valuable across time.

HOAA's portfolio demonstrates versatility across building typologies, from intimate residential projects such as the recently completed House in Nakano to larger commercial ventures including a 1,570-square-meter hotel in Kamakura and an eight-story office building in Shiba Park. Each project reflects the firm's commitment to cost-performance optimization without compromising spatial quality or material integrity, establishing HOAA as a practice capable of balancing economic pragmatism with architectural ambition.