Tsuruoka House in Tokyo: Of plants, people and the pursuit of harmony

As I sit on the 11^th floor of my urban apartment surrounded by city life that has hacked away at the natural environment, I see a living proof that nature is resilient. My neighbour’s window ledge is covered in weeds growing out of the building’s concrete. There’s even a pretty robust ficus that refuses to be diminished. They cut it, and a few months later, it grows right back. This is not an environment of fertile soil or regular watering. Yet the plants keep growing. If it can happen without human intervention, then why can’t architecture be designed to make it flourish?

“The earth is a formless assembly of various living organisms, including humans. Could architecture be a vessel to hold these organisms as one whole unit?” This question led architects Kiyoaki Takeda and Miyuki Sakuyama, of Kiyoaki Takeda Architects, to create a spectacular house in Tokyo. The team designed the dwelling to include multiple layers of gardens and spaces that were capable of housing plants, wildlife and the people it was built for. 

Founder Kiyoaki Takeda explains, “I encountered an article published in a scientific journal (that stated) human-made artefacts, referred to as anthropogenic mass, have begun to surpass all global living biomass…the dominant cause of this trend is construction materials. This condition implies it has reached a limit to keep generating the ‘architecture solely for humans’ produced so far. Tsuruoka House is an architecture that attempts to hold not only people but also other life forms.”

For plants and people

Completed in 2021, the waterfront property located in lush park of Japan’s capital features a series of vaulted slabs filled with soil for the plants to grow. “Rainwater flows from the mountains to valleys of the vault slabs and is carried vertically from valleys through the core. The water flow generated the shape of the building,” Takeda explains.

While the concept of plant covered homes is by no standard a new one, what the architects attempted was to create a garden that would eventually become an environment in itself. “Usually, the site is often divided into gardens and houses in a two-dimensional plan. However, with this design method, the relationship between nature and architecture tends to be just next to each other,” says Takeda. The design approach was to ‘stack’ gardens and houses on top of each other in a cross-sectional plan.

Typically, green roofs have a thin layer of soil that can support plants that don’t have deep roots. “The thickness of the soil was plotted as deep as possible so that the layered garden would be a small forest hosting a mixture of ground cover plants, shrubs and small trees. By opening the garden to other available life forms, providing them with a place to inhabit, and co-creating the community, the garden becomes an environment,” says Takeda.

Architecture for the environment

The thing about creating architecture where a natural environment can flourish is the fact that this natural environment cannot be controlled. The Japanese firm needed to make sure that the construction would be sturdy enough to hold up this flourishing environment they hoped would grow out of it. Takeda explains, “The compost itself is already heavy. On top of that, there are weights of torrential rains, growing and increasing plants every year that need to be considered…, the more the design progressed, the scarier it was to embrace the environment.”

The whole structure features visible concrete and steel sections strong enough to take on the growing weight. The vaults are designed to accentuate the flow of water with overflow pipes that drain the excess rainwater into the ground. “(We also) designed the soil foundation with layer structure by placing high-density compost with water retention at the upper level where the plant roots can reach and positioning low-density compost with clear drainage at the lower level,” adds Takeda. They reduced the weight by limiting the soil location on the rooftop and around the periphery of interiors and exteriors to allow transpiration to soften solar heat.

An attempt at harmony

Takeda mentions, “During the construction, a serious doubt still remained in my mind. The environment supported by the building structure is ‘managed nature’ by human hands. Shouldn’t the environment mean ‘untouched nature’?” Reaffirming his aim for the project – to showcase that architecture for humans could also be for the environment, and vice versa – Takeda created a structure which tries to respect the supply and demand among all beings in every direction.

“If we could establish a structure that fosters mutual and complementary relationships to each other, it might be possible to seek a direction for future architecture. At ‘Tsuruoka House’, over time, the plants will grow, and birds and insects will introduce unplanned species. Eventually, a small forest could appear. Then, after decades, existing life forms will grow and hide the building entirely, and ultimately, their bio-mass must surpass the mass of human-made architecture,” he concludes.

*Architect Kiyoaki Takeda’s inputs were translated by Mami Sayo.