Ryohei Tanaka of Japanese architectural firm G Architects Studio designed a bijou coffee stand in Kyoto that features a green patination brought about using soy sauce and chemicals.
The coffee stand is a project for AoQ, a new brand established by Kyoto-based Suetomi, a renowned maker of traditional Japanese confectionery known as wagashi. The stand is on the ground floor of a two-story wooden building — sited on a built-up intersection, it is surrounded by characterless hotels and offices.
G Architects Studio works to create harmony between the past and present, something that is particularly pertinent in the historic city of Kyoto where change is ever pervasive.
The coffee stand’s depth is just one meter, “so small and modest that it can almost be missed in the busy street,” says G Architects Studio. With such a narrow plot, the cafe’s floor plan was determined relatively quickly: the kitchen (with a takeout counter) and an adjacent seated area (with a bench and small Japanese garden), face the street front. G Architects Studio spent time pondering over the facade’s materiality, opting to chemically engineer the aging of copper.
The studio affixed copper foil to the coffee stand in two specific places: on the side of the stand facing the intersection and in the seated area. The copper was then oxidized with soy sauce and chemicals giving it a rusty patina reminiscent of “Suetomi blue”, the confectioner’s corporate color. Suetomi’s original store is a three-minute walk from the coffee stand — the stand therefore also acts as a signboard, leading customers to the shop on Tamatsushimachō in Kyoto’s business district.
“Cityscape regulations control the use of facade colors except for natural materials,” explains G Architects Studio. The color’s use was therefore permitted by the local government because it was created by oxidizing the copper (as opposed to painting it a greenish-blue).
To achieve the effects of natural oxidation, soy sauce was used to slowly corrode the copper, turning it reddish brown; ammonium chloride was then applied, quickly corroding the copper further and producing its patina color. Under normal circumstances, where the copper is simply exposed to the elements, it would have taken years to achieve this patination.
When the coffee stand is closed, a roll screen made from mesh sheet (typically used as scaffold debris netting) covers the seated area. When lit as night it resembles a bamboo blind and allows passersby to see the patina color. “It functions as a ‘street lamp’ for pedestrians, but also as a billboard for the store,” says G Architects Studio.
Floor area: 10.17 square meters (109.5 square feet)
