slanted lines and staggered floors create alternative spaces inside tokyo’s diagonal house

the resulting compositions bring about spatial continuity while encouraging alternative activities to unfold.

lea zeitoun April 5, 2023 3 min

‘diagonal house’ by Daisuke Ibano + Ryosuke Fujii (id+fr)

Tucked in the middle of a dense residential area of Tokyo, ‘Diagonal House’ is a new housing structure designed and built by architects Daisuke Ibano and Ryosuke Fujii (id+fr) for a couple and their children. With the front half of the lot belonging to the category 1 height control district, the setback regulation imposed a strict height limit on the surrounding area, pushing id+fr to explore the different ways of situating the building in such a packed townscape. ‘The client, who spends a lot of time cooking, requested the kitchen, living space, and terrace in this new house to be integrated. We responded with a building comprising staggered floors, which brought about spatial continuity and smooth vertical circulation,’ begins the duo.

slanted lines and staggered floors create alternative spaces inside tokyo's diagonal house - 1 — all images © Takuya Seki

encouraging spatial continuity and alternative activities

To further emphasize this spatial continuity inside ‘Diagonal House’, id+fr (see more here) injected a slab above the living room, folding upwards along a slanted line. Meanwhile, the duo partially raised the uppermost slab to make room for a large kitchen terrace opening. ‘These design arrangements resulted in some features that encourage alternative activities: the sloped floor of the terrace can be used for sunbathing, and the space underneath the raised section of the topmost slab became an alcove for sleeping,’ explain Daisuke Ibano and Ryosuke Fujii.

These compositions also triggered other design decisions, namely integrating platforms at a diagonal angle with the stairwell running between the staggered floors, adding a corresponding angle to storage on the opposite wall, and lastly, placing a triangular light garden at the end of a large opening in the living room to create a diagonally oriented axis, making it feel more spacious.

slanted lines and staggered floors create alternative spaces inside tokyo's diagonal house - 2 — ‘Diagonal House’ tucked in a dense neighborhood of Tokyo

As such, the countless diagonal lines, resulting from careful examinations of the level of visibility and the relationships between the spaces, became a signature feature encouraging connectivity to the exterior. ‘We strived to create a home that sits harmoniously among the varied forms of surrounding residential buildings and a microenvironment in which the family can feel a sense of urban life wherever they are inside the house,’ concludes id+fr studio.