Yakushima Island is a natural paradise in southern Japan where abundant rainfall onto 2,000-meter peaks nurtures dense forests.

This innovative housing co-op applies "regenerative architecture" to rethink the relationship between human habitation and this nature. The name Sumu means both "to live" and "to become clear," expressing its core concept of living in a way that positively impacts the landscape.

Rather than being a discrete site, the design takes a holistic view of the entire river basin, from the mountains to the sea, making a positive contribution to natural processes.

Sumu is an experimental housing co-op jointly created by eight owners. Made for use by the owners and trusted friends, it is a place for tending to nature while reflecting on values.

It applies "regenerative architecture," a new approach developed by the designers that combines traditional Japanese civil engineering with contemporary technology.
Going beyond simply preserving nature as it is today, key considerations in the design are:

1) Designing the underground environment

2) Orientating buildings based on in-depth understanding of water and air flows through the landscape
3) Creating an ongoing connection with nature through architecture

Sumu comprises several separate buildings to enable a layout that respects the original natural landscape. The buildings protect the tree roots and reduce the impact of the wind, while stones supply minerals to the surrounding soil and foster tree growth. Tree roots passing under the buildings support the soil, an act of symbiosis between nature and architecture.

[Underground design]
The design also extends underground. Burned wood is placed under the foundations, and carbonized surfaces promote the growth of mycelium, joining the buildings to the soil network. This promotes a symbiotic effect whereby tree roots grow under the buildings and support the soil.

The off-grid kitchen made with local cedar features a solar-powered radiant heat cooker, while water is drawn from the river basin, then cleaned and returned to nature after use.

Lights made from local soil fill rooms with light embodying the color of the surrounding earth, and plaster made from a hemp charcoal/EM bacteria mixture provides healthy, comfortable spaces by preventing putrefactive bacteria.

[Buildings in cerculation]
The buildings and decks are raised, dispersing wind flowing between the mountains and the sea without blocking it. This allows the forest to breathe, promoting healthy air and water circulation. Despite the humid climate, this ventilation prevents moisture accumulation that may damage the buildings.

Naturally-derived persimmon tannin is applied to the wooden structures near the soil to prevent erosion by insects. The result is a space that breathes together with the surrounding forest.

Plaster made from a mix of charcoal and effective microorganism (EM) bacteria provides a healthy, comfortable space by preventing mold and other putrefactive bacteria.

[OFF GRID]
Sumu has developed a new methodology called “regenerative architecture,” whereby the buildings enrich nature. In addition to exploring modern applications of traditional Japanese wisdom, its features include:
1) 100% off-grid energy from solar power, storage batteries and local firewood

2) Comfortable living spaces that leverage architectural expertise to achieve effective airtightness and insulation unlike camp-style accommodation

3)Modern spaces with stylish design

A major departure from conventional nature experience facilities, Sumu encourages a wider section of society to engage in learning with the aim of bettering our planet’s future.

[Regenerative Lifestyle]
True to its concept of making a positive impact by living among nature, Sumu residents adopt a “regenerative lifestyle” that enhances the environment through everyday activities, from collecting driftwood for use as firewood to clearing grass to allow cool air to flow through in a way that benefits the landscape.

Sumu's design changes our relationship with nature. It enables residents to discover new possibilities for interacting with nature and adapt the way they think and act, building relationships with nature that transcend generations. Its unique approach has the potential to accelerate environmental initiatives if more widely applied.

[Positive Impact to nature]
I believe that regenerative architecture in Yakushima will become a prototype for similar types of architecture in the world.
This construction method can be applied anywhere in the world as long as it rains and there are microorganisms in the soil.
Whether it is a natural environment or an urban environment, building work destroys the local environment. And the buildings that call themselves ecological architecture are only mitigating the damage a little.

Sumu's regenerative method builds buildings while keeping the microorganisms in the soil alive, and by activating the bacteria, the artificial building can connect with the natural network. By doing so, it is possible to help each other with the surrounding environment and change the environment more positively.

Since the Industrial Revolution, humans have destroyed and consumed nature. If this regenerative architecture spreads throughout the world, I believe that the global environment will recover at an astonishing speed. The most innovative is the change of architecture from negative impact to positive impact.