Japan-based Hiroshi Nakamura & NAP has offered a look inside their recently completed Library of the Earth. Situated in the Japanese city of Kisarazu, and completed in April 2022, the library is described by the firm as “the library for the farmers, plowing the fields on sunny days and reading books on rainy days.”

Located in the corner of an active agricultural site, the scheme saw Hiroshi Nakamura & NAP transform a debris-laced plot into a “lush valley.” At the core of the project is a submerged library designed with the principle that “architecture should not occupy the cultivated soil layer but rather exist humbly under the flourishing of plants and microorganisms in the soil.”

“The earth has been regarded as the source of all life and a symbol of motherhood,” the team explains. “Our wish was to make a small cleft in the earth and create a tranquil place suitable for farmers to rest. The cleft looks like a water drop when viewed from above. As you wander into the approach and pass through the plowed ground, a corridor of bookshelves appears.”

Inside, the scheme is supported without beams and columns, while concrete void slabs cantilever out from the outer retaining walls and wing walls. All floors, walls, and ceilings have an earthen finish, while on the building’s courtyard perimeter, a lawn wraps around the vertical face of the ceiling slab to “give the space a sense of dampness.”

The ceiling heights are determined by the slopes of the ground, leading to low-rise areas and hidden rooms for children. At the deepest part of the cave-like interior is a hall for storytelling, described by the team as a “womb-like space that uplifts the lawned ground” in which “folds of bookshelves surround the stepped seats, and books from the collections of farm workers and books for children line up.”

In the hall, bookshelves are formed from 40-millimeter-thick vertical frames that extend overhead to support the space. “When a thin vertical beam supports the next one, and that vertical beam is also supported by its neighbor, a large space can be supported as a whole when the repetition makes a circle,” the team explains. Meanwhile, a top light at the center of the structure frames a view of the sky through a camera obscura pinhole effect.

“The vertical piers forming the structure of the reading hall are laminated wood made from thin boards that have been curved and glued together,” the architects add. “The construction of this reciprocal structure was extremely challenging due to the necessity of assembling all the complex pre-cut joints before completing the structure. The top light in the reading hall is retractable and features a natural gravity ventilation system that draws air in from the courtyard side and expels it through the top light.”

The library is one of several Japanese projects to recently feature in our editorial. Last month, we covered the opening of OMA’s new Toranomon Hills Station Tower in Tokyo, while in September, we profiled a ‘home for tea and life’ in Kyoto. Last year, meanwhile, we devoted a feature article to Hiroshi Nakamura & NAP’s Kamikatsu Zero Waste Center, which we described as “a temple to material reuse.”