Interior Space and Exhibition Design Itomachi Hotel 0 Interior by Ikuma Watase Itomachi Hotel 0 is a hotel interior and landscape design located in Saijo, Japan. The hotel uses solar power systems and ecological materials, and is the first hotel in Japan certified as a Net Zero Energy Building. The design is based on two local resources, Uchinuki groundwater drawn from wells and Iyo Blue Stone. Each guest room has an open washbasin facing the entrance, and Uchinuki is also placed in the central courtyard, so the sound of water is heard throughout the hotel. The design supports the revitalization of the town.