Tenant building planned for a site facing Kaminarimon Ichinomiya-dori, just outside Exit A4 of Asakusa Station on the Ginza Line. The planning was carried out in anticipation of the return of inbound customers, while customer traffic had slowed due to the Corona disaster.
With such a narrow frontage and deep site (5.8m x 20m), the designers initially considered taking the openness of the façade by installing a glazed lift and evacuation balcony at the front and an outdoor evacuation staircase at the far end. When we participated as design supervisors, our first concern was the outdoor escape route, which occupied 1/3 of the first floor. The idea was to use a pilotis to bring an alley-like facade into the site, but the problem seemed to be that the leased area on the first floor was only 37 m2, whereas 60 m2 could be secured on the standard floor.
Rather than building a balcony only for evacuation in the narrow frontage, it was thought that bringing the outdoor evacuation staircase to the front, increasing the leased area on the first floor and creating a new facade in front of the outdoor evacuation staircase would have more impact on the street. The entire facade is set back from the site boundary, creating a pocket park against the street. The outdoor evacuation staircase in the façade is located on the first floor, and it is designed to pop out from the façade and invite people to the second floor. The outdoor evacuation staircase and evacuation balcony in the front are separated by a fireproof wall in order to maintain their independence while being next to each other.
As for the façade, studies were continued to obtain the necessary opening ratio for the outdoor evacuation staircase, while maintaining the Japanese taste expected by inbound visitors to the Kaminarimon. Initially, we considered a facade based on the motif of a tea-ceremony room base window, or a more delicate shoji-like lattice, using a bundle of scaffolding mono-tubes with plating. Ultimately, various variations of the braided latticework were included within a larger frame, such as a Mondrian grid, which allows the entrance to the sheltered balcony to be naturally incorporated. Kumiko patterns are known as auspicious patterns, and are an ancient Japanese pattern that is associated with health, good harvests, prosperity and longevity.
The latticework on this façade is based on the motif of the sesame seed, which was treated as a medicine for longevity and immortality; the ‘Sa-ayagata kuzushi’, which has the meaning of uninterrupted longevity; the ‘Shippo’, which wishes for family happiness, wealth and prosperity; the ‘Senbon lattice’, which has the meaning of repelling evil; and the ‘Tei-tsunagi’, which combines triangles to symbolise the stability of power. The latticework is a rhythmical façade. The first-floor façade is made of panels of cypress braid sandwiched between glass panels, expressing the delicacy of the braid. The delicate nature of the Kumiko is expressed in the panels.
