Metal Architecture Home

Back to the Garden

Japanese garden design reconnects the human experience to nature

Japanese Garden Nov17

The fundamental approach of Tokyo-based Kengo Kuma and Associates is to connect or even re-connect the human experience to nature by way of architecture. For the Portland Japanese Garden’s Cultural Village, Portland, Ore., this approach was quite easy according to project architect Balazs Bognar, AIA, design director, Kengo Kuma and Associates. He calls the garden’s site “a terrain full of possibility.” The project did connect so successfully in fact, that judges awarded it the 2017 Metal Construction News Building and Roofing Awards’ winner in the Metal Roofing (new construction) category.

Since opening in 1987, the Portland Japanese Garden’s attendance has risen from 30,000 to 300,000 in annual visitors, with interest projected to continue growing. An expansion and renovation called the Cultural Village acts a main square, but the garden’s buildings are meant to take a backseat to the landscape. The site and its landscape are unique because, “The distinctive trees of the Pacific Northwest, combined with more than 50 years of the art of Japanese garden design are a rare-if-unheard combination, even in Japan,” Bognar says. Sadafumi Uchiyama at the Portland Japanese Garden was the landscape architect.

Multiple buildings were chosen partly because of the concept of monzenmachi; loosely defined as the villages at the gates of shrines or temples that provide a metaphorical stepping stone to places of pilgrimages. “A village configuration has the added benefit of being far more humanly scaled than a single mass of building,” Bognar says. “Multiple buildings allow for spaces and the associated gardens to flow between, and to suggest that the architecture is not a single object separated from a surrounding field, but instead a series of moments and interventions suggesting a more fluid, more open-ended experience, subject to the experience of the individual visitor.”

Metal in the Garden

Each building features a vegetated roof and an aluminum porch-like roof that wraps it and provides a protective canopy. The terraced gutters capture all the runoff and rainoff not captured by the green roof. The buildings at the Portland Japanese Garden are made of steel, after having been initially proposed as wood in 2010. This is significant, because ironically it was steel and not wood, that helped the Kengo Kuma and Associates design team to minimize dimensions to a more traditionally recognized carpentry measurement, approximating four inches.

“This had much to do with the size of a hand, which in turn was used as a way to size pieces of timber correctly, in traditional Japanese carpentry,” Bognar says. “The strength-to-weight ratio of steel meant that we could minimize the presence of structure (4x4-inch steel columns throughout), and cantilever all corners to allow for the free flow of space between the inside and outside. [This] maintains very deep eaves with elegantly thin plates of steel for the rafters as a way of experiencing Portland's famously rainy weather while still being under cover. In other words: steel permitted visual lightness in deference to the heavier, rich totality of one's experience of the landscape, from the bottom of the steep hill to the gardens at the top.”

The aluminum metal panels deployed for the lower roofs exhibit a distinct pattern that is reminiscent of a hand-applied enamel finish. Because of the area required, this proved to be cost prohibitive. So, this hand-applied finish was produced digitally, using Japanese scanning and printing technology courtesy of Kengo Kuma and Associates collaborators at DNP, Tokyo, and Pure + Freeform, Oakdale, Minn. Portland, Ore.-based Hoffman Construction was the project’s general contractor.

“Metal panels allowed for the edges of the roof to attain a thin, crisp, and high resolution, something unusual for sloped roofs in the United State,” Bognar says. “Our intent is to show refinement and careful attention to materials, often manifested as thinness, and as maximized limits of the material properties. Thus, metal in our project oscillates between an origin in a crafted, handmade idea, and realization via a distinctly high-tech method.”

Custom Aluminum Finish

Pure + Freeform designed the custom aluminum finish, called Celeste Stone, which was used on the three main pavilion buildings’ pitched roofs and facades. It was based on a custom, handfinished three-coat baked enamel sample provided by Bognar. “The approved design featured eight coats of pearlescent and organic inks sealed with a LUMIFLON/Fluoroethylene vinyl ether (FEVE) resin, which is a next-generation fluropolymer, with 3-mm aluminum at the base,” says Geoffrey Hahn, creative director at Pure + Freeform.

“Recently, using metal typically signifies something modern, distinctive or opulent, but the focus of this project was the natural splendor of the site itself,” Hahn adds. “By using an extreme matte coating with a muted slate grey color, the metal is instead supporting nature, taking a backseat to the breathtaking landscape. Our ability to manipulate color, gloss, texture and design while keeping the metal colorfast really allows the project to be specific to the site, creating a sense of place and community, which ultimately is the aim of this addition.”

Judges were especially impressed with the project’s aesthetics and detailing. “[They] were really well done and not the type of normal metal roof you [usually] see in terms of proportion and flatness,” Bencher says. Wray was impressed with the roof and its razor-sharp edge, which he says dictates a horizontal plane. “I love the very horizontal plane,” Wray adds. “I love the overhang and the shadow, and how it creates a wonderful relationship between the roof and ground. The space between is nice; it is really seamlessly woven in an elegant way.”

This is not the first time the Portland Japanese Garden has been honored. It won in the metal roofing category in the 2017 Metal Architecture Design Awards.