This is the first facility in Nara Prefecture to integrate the national and prefectural government offices with the city hall.
Gojo-shi prospered as a strategic location for river transport along the main road, and it still retains its historic streetscapes, including the national treasure Eizan-ji Temple (Octagonal Hall), built in the Nara period, and Gojo Shinmachi, a designated district for the preservation of significant historic buildings.
Gojo is also mentioned in the famous line, "Yamato Gojo no Akane-zome (Madder dyeing of Yamato Gojo)" from the Joruri (traditional Japanese puppet theater) play "Hadesugata Onna Maiginu (Alluring figure, a woman's dance robe)." In keeping with this, Gojo-shi is promoting the revival of the traditional color, Akane (red color made from madder dye,) to revitalize the region and has incorporated the Akane color into the city hall as a symbol for carrying on traditional culture and revitalizing the region.
The ceiling of the Gojo Mall is made of wooden louvers that depict the ridgeline of Mt. Kongo.
We indicated the coordinates on 37 cross-sectional drawings and did our best to convey what we wanted them to do to the builders. The struggle began with trial and error to figure out how to build it. The builders took the initiative to introduce 3D digital fabrication, numbering each component with a different shape and verifying the accuracy of the mock-up while repeatedly checking for interference and shape. Later the builders told us, "Without the coordinates, we wouldn't have been able to assemble it." This may be because the intentions behind the drawings were successfully conveyed to them. We debated whether to black out the backing boards that hold the wooden louvers in place but instead decided to leave them unpainted to convey the beauty of the handiwork.
A place has been created where local companies can proudly demonstrate the excellence of their craftsmanship to the community.
As a disaster prevention base in southern Nara Prefecture, Gojo-shi must be able to continue its operations even after a devastating earthquake. In adopting a seismic isolation structure, we used PML (probable maximum loss) to compare its effectiveness with that of a quake-resistant structure and shared the results to all parties involved that it would produce equivalent or higher benefits in terms of life-cycle costs, even though the initial cost would be higher. We used the seismic isolation experience vehicle to provide those involved with a hands-on experience of the benefits of seismic isolation so they could deepen their understanding of the necessity of a seismic isolation structure.
In addition, we left the ceiling open to prevent ceiling materials and heavy equipment from falling while adopting underfloor air conditioning. We also provided backup infrastructure to achieve a city hall that ensures safety and security.
The air conditioning plan effectively combines passive and active methods, taking advantage of the climate characteristics of Gojo-shi. We adopted systems that not only consider energy conservation but also the comfort of the workers, for example, 'dry' air conditioning using desiccant air conditioners, air conditioning units with minimal drafts (with floor outlets), and airflow systems around windows.
The large roof uses a 'double roof system' that serves as an air intake route when the heating is on. A thermal simulation confirmed a maximum temperature increase of 9°C, and solar heat is effectively utilized to provide energy for air conditioning. In addition, we established three air conditioning and ventilation modes to efficiently operate natural ventilation during the interim period, aiming to extend the period of using the Eco Void and improve its effectiveness.
To adjust the budget, we narrowed down the functions of the city hall building above the seismic isolation structure to the absolute minimum that could be shared by the national, prefectural, and municipal governments. For this reason, the "Nigiwai Hall" was designed as a low-cost, single-story wooden building. Since the roof span was set at 7.85m to meet the required facility functions, tension-string beams were adopted with the joints located at the points where the moment was minimal. This made it possible to construct the building using wood that is generally available on the market and reduced the construction costs.
The L-shaped floor plan was arranged so the building gently wraps around the plaza with a camphor tree that preserves the memory of Gojo High School. At lunchtime, one can see citizens enjoying their lunch. At lunchtime, you can see citizens enjoying their lunch. Our plan to build it as a separate building led to an easily accessible and friendly facility. We hope that people will continue to cherish this facility, which serves as a place where citizens can gather during events while also transmitting and experiencing the appeal of the area.
The facility provides citizens a sense of security by functioning as a disaster prevention base. People also commented that the parking lot had been enlarged and the city hall's interior had become brighter. Events held in the city hall space are well received by the citizens, contributing to revitalizing the local community.
The new city hall has improved the staff’s working environment and brightened the atmosphere of the whole city. The scenery that the project members had envisioned now spreads before our eyes. (Written by a member of the New City Hall Construction Promotion Team)
