photovoltaiCapsules: Solar Spheres That Turn a Steel Truss Into a Place to Nap and Meditate in Seoul

Most buildings treat solar panels as an afterthought bolted to a roof. photovoltaiCapsules makes them the room itself. Every place to lie down is a sphere clad in photovoltaic cells, and the building is what happens when dozens of those spheres are lifted into the air, braced by steel and strung along open galleries. The result reads less like a facade and more like a cluster of molecules caught mid-reaction beside a concrete tower.

photovoltaiCapsules is designed by Ida Hardt for a site in Seoul, South Korea. The project was named Winner at Cocoon. Its premise is compact: a photovoltaic capsule module that adapts to each user's individual needs, offering a private place to nap or meditate in the middle of a dense city.

A Gallery Threaded Between Solar Spheres

The most telling view is from inside the frame. A straight concrete walkway runs down the middle, horizontal steel members stack overhead like a ladder laid flat, and the capsules sit on either side, each opening onto the gallery through a cut-away door with its own small stair. Timber lines the inside of every sphere, so the walk becomes a row of warm, lit thresholds set into a dark, gridded skin. The gallery is circulation, but it also works as a street of front doors where people pass, pause and step up into their own space.

Three Low Floors Set Against Seoul's Towers

The project's boards place the building among high office and residential blocks, and the response is deliberate contrast. Instead of competing for height, the scheme holds to three floors. A plain concrete cuboid carries stairs, lifts and toilets, echoing the simple shapes of its neighbours, while the capsules spill out around it. The core gives the composition a steady spine; the spheres give it a silhouette you would remember from across the street.

The sections and elevations show how disciplined the arrangement is under its playful outline. The capsules stack on a regular rhythm, with floor levels marked at roughly three-metre intervals, railings and balconies tucked between spheres, and the glazed core standing alone at the centre. The grid behind the cluster is what makes the module claim believable: add or remove spheres and the order survives.

A Truss Where the Capsules Act as Joints

Beneath the upper floors, the structure is left exposed. Diagonal and horizontal steel members brace one another, and the capsules sit at their meeting points so that the truss and the rooms read as one system. On the ground, a timber deck and dense planting fill the spaces between the legs, with vines trailing from the slabs above. This interplay between capsule and frame is what caught the attention of Junwoong Seog, Director & Chief designer at BY SEOG BE SEOG, who judged Cocoon. He acknowledged that the competition's conditions pushed many entries toward similar starting points, and singled out how this one carried its idea through.

I think the start of this project is similar to other nominations because of the conditions given to this competition. I think this project has a very good process and results after that. In particular, I think that the relationship between the capsules and the structure that supports the capsules has been successfully proposed in terms of space. And I think the nature-friendly approach is also good.
Good luck.Junwoong Seog, Director & Chief designer, BY SEOG BE SEOG, South Korea

Tent-Shaped Rooms for Gathering at Ground Level

Privacy is only half of the programme. The ground floor opens into a common, semi-open space with separate rooms for group meditation, workshops and conferences. These rooms take a tent form with translucent white walls, timber floors and almost no furniture beyond mats, cushions and plants. Light comes in softly from all sides, and the emptiness is the point: the same room can host a meditation class one hour and a rented event the next.

Two Chambers Inside Every Sphere

According to the project's boards, each capsule splits into two chambers, giving fifty capsules a capacity of one hundred people. Inside, the user controls the conditions: an adjustable bed, an automatic window, temperature settings and built-in speakers, wrapped in light colours and wood. The round shape is not only a formal choice; it exposes more surface to the sun across the day, which is how the panels aim to make the building energy self-sufficient. The open frame also keeps distance and ventilation between users, a concern the project ties directly to living through the pandemic.

Why This Project Matters

photovoltaiCapsules takes a familiar urban need, a quiet place to rest during the working day, and answers it with a single repeatable unit that does several jobs at once. The capsule is a bedroom, a meditation cell, a structural node and a power source. That economy of ideas is what lets the building stay small in scale while still holding a clear presence among much taller neighbours.

Its larger lesson is about where environmental performance can live in a design. Rather than hiding energy generation, the project puts it on the skin of the most intimate space a person occupies, and then builds the social life of the building, galleries, gardens and shared rooms, in the gaps around it. It is a reminder that sustainability and comfort can share the same surface.

View the Full Project

Project team

Designer: Ida Hardt

Competition and award

Winner, Cocoon

Jury

Junwoong Seog, Director & Chief designer, BY SEOG BE SEOG, South Korea

Location

Seoul, Korea, South

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