by Tsukasa Ono

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.
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.
Off-grid energy from solar power, storage batteries and local firewood while water is drawn from the river basin, then cleaned and returned to nature after use.
The plaster of the wall made from a hemp charcoal/EM bacteria mixture provides healthy, comfortable spaces by preventing putrefactive bacteria.
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.The result is a space that breathes together with the surrounding forest.
Distinction:Best Sustainable House 2023 Category:Sustainable HousesYear:2022Location:Kagoshima JapanArchitects:Tsukasa OnoLead Architect: Tsukasa OnoDesign Team: Tsukasa Ono, Tomonari Waku, Ben Nagaoka, and Manami IwashitaContractor:Motchom Create,Nobuyuki Shimazaki, IKIYASOOBOU,NOBIRA KENCHIKUClient: Sumu YakushimaPhotographer: Rui Nishi