OMA's Largest Built Work Splits a 266-Meter Tokyo Tower in Two to Let the City In

Most supertall towers in Tokyo treat the ground plane as an afterthought: a lobby, a turnstile, maybe a convenience store. OMA/Shohei Shigematsu's Toranomon Hills Station Tower does the opposite. It cracks itself open at the base, lifts its structural core to either side, and turns its entire ground level into a funnel that pulls pedestrians, subway riders, and shoppers into a continuous interior streetscape. At 266 meters and 49 stories, this is OMA's first ground-up building in Tokyo, and it is also the firm's largest completed project anywhere. That it reads less like a monument and more like a piece of urban infrastructure says a great deal about what Shigematsu was after.

The concept is deceptively simple. Shintora-dori Avenue, a newly laid corridor running from Tokyo Bay toward the center of the city, terminates at the tower's site. Rather than blocking that axis, the design extends it vertically, creating a central band of public activity sandwiched between two asymmetrical slabs. The north slab begins wide and tapers upward in deference to the Imperial Palace. The south slab does the inverse, widening as it climbs to capture views of Tokyo Tower and the Roppongi Hills skyline. Between them runs a continuous seam of lobbies, atriums, staircases, lounges, and cultural venues, from the subway platform underground all the way to a rooftop sky garden 49 floors up. It is a vertical boulevard, and it works.

The Avenue Extended

Seen from street level along Shintora-dori, the tower's stepped glass profile registers as two distinct volumes rather than one monolith. The unitized curtain wall, built from low-E insulating glass with thermal insulation in the spandrels, follows staircase-shaped surfaces that shift angle at different floor heights. These facets break up the scale of the facade and catch light differently throughout the day. From a distance, the stepping reads almost geological, like a crystalline formation rising from the tree-lined boulevard.

The decision to split the tower into two slabs in inverted symmetry is not merely formal. It allows the building to address very different urban conditions on its north and south faces while maintaining a legible central axis. The result is a tower that looks dramatically different depending on your vantage point: narrow and almost blade-like from the east and west, broad and civic from the avenue approach.

The Base as Urban Funnel

The real innovation happens at the bottom. The base is expressed as a large funnel, its glazed walls angling inward to draw pedestrians from the street into a layered interior. The core, typically the dense, opaque center of any high-rise, has been split and pushed to the flanks of the plan, liberating the heart of the building for public circulation. This move opens up a roughly 2,000-square-meter Station Atrium that extends three stories down to the Toranomon Hills Station on the Hibiya Line. It is the first underground metro station in Tokyo to be flooded with natural daylight, and the effect is striking: riders ascending from the platform step into a bright, airy concourse rather than the usual dim tunnel.

Above the station level, an elevated pedestrian bridge called T-DECK, 20 meters wide, slices through the base and connects the tower to the rest of the Toranomon Hills developments. This bridge effectively splits the lower retail zones into two distinct territories while creating a continuous loop of greenery and activity across what was previously an arterial road. It is a piece of urban stitching that makes the tower feel less like a destination and more like a node in a larger network.

Cultural Crown: TOKYO NODE

The top of the tower hosts TOKYO NODE, a cultural center conceived jointly by OMA and Mori Building. The program includes a laboratory, three gallery spaces, a sky garden with an infinity pool, and restaurants. Two of the most compelling spaces are its performance and theater venues, which deploy floor-to-ceiling glazing to dissolve the boundary between interior and skyline. In the performance hall, a timber floor and black ceiling grid sit against gridded windows that frame the city at dusk, turning Tokyo itself into a backdrop. The theater takes a similar approach: tiered seating faces a stage framed entirely by glass, so the audience watches performers against a panorama of lights.

These are not conventional black-box venues. They are calculated provocations, spaces that argue cultural programming and urban spectacle are not separate categories. Whether the glazing proves practical for every type of production is debatable, but as a statement about what a skyscraper's top floors owe to the public, they are bold.

The Sky Terrace

At the rooftop, the twin-slab logic of the tower is fully legible. Two volumes stand side by side, connected by a horizontal screened bridge, with a landscaped terrace and pool occupying the gap between them. It is the architectural equivalent of pulling a building apart at the seams to let air and sky through. The pool, positioned at 266 meters, is not just an amenity; it is a spatial event, a datum line that registers the scale of the city below.

Seen from the moat at twilight, with the tower's reflection rippling against the stone embankment, the building takes on a quieter register. The stepped glass surfaces glow rather than glare, and the split profile reads as two slender lanterns rather than one massive block. It is a useful reminder that for all its programmatic ambition, the tower also operates as a landscape element, something that Tokyo's historic waterways frame rather than resist.

Sustainability as Baseline, Not Branding

The tower has been pre-certified LEED Platinum and is on track for WELL Platinum certification. It runs on 100 percent renewable electricity from day one and generates energy on-site for area-wide supply. These are significant achievements for a building of this scale, but what stands out is how little they are foregrounded in the architecture. There are no solar fins or green walls performing sustainability for the camera. Instead, the environmental strategy is embedded in the curtain wall assembly, the daylighting of the station below, and the passive ventilation logic of the split-slab plan. It is sustainability as engineering discipline rather than architectural ornament.

Why This Project Matters

The Toranomon Hills Station Tower matters because it treats a supertall building not as an object but as a connector. By extending the axis of Shintora-dori Avenue vertically through the structure, by splitting the core to open the base, and by threading a 20-meter-wide pedestrian bridge through the podium, OMA and Shigematsu have produced a tower that is porous in ways most high-rises cannot even conceptualize. The subway station with natural light, the cultural center open to the sky, and the rooftop pool between twin slabs are all manifestations of the same idea: that height should amplify public life, not retreat from it.

As OMA's largest completed project and Mori Building's capstone for the Toranomon Hills district, the stakes were high. The tower had to function as transit hub, office complex, hotel, retail center, and cultural institution simultaneously. That it manages all of this without collapsing into incoherence is a testament to the clarity of the central band concept, a single organizational idea strong enough to absorb enormous programmatic complexity. In a city that builds supertalls at a relentless pace, this one earns its place by giving back more than it takes.

Toranomon Hills Station Tower by OMA/Shohei Shigematsu. Toranomon, Minato-ku, Tokyo, Japan. 253,540 m². Completed 2023. Photography by Tomoyuki Kusunose.

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