Eco Hanok
Architecture and Material R&D Assemble + BC Architects&Studies&Materials + Atelier LUMA Material R&D Yoon Jungwon / Architecture Production Curator, Kim Hyeong Ki / Laboratory on Construction and Building Materials, Chosun University Production Support Dream Lime, Claymax, Goryeong Roof Tile, Sejin Plus Construction and Local Design Support Stuga House + Urban Society + Songryunjae Landscape Design Lee Sanghoon + Shin Dayoung / VNH + ANPARK Crafts October Kim Studio, Jangjibang, Studio Ohyukyoung 3D Scanning&Modeling Techcapsule Eco Hanok Location 209-106 Dongmyung-dong, Dong-gu, Gwangju Photograph Captions Yoon Jungwon, Pai Hyungmin
Responding to the climate crisis through architecture and design, Assemble, BC and Atelier LUMA simultaneously create beautiful everyday spaces. Restoring an abandoned hanok and its garden in Dong-gu, Gwangju, a small but special eco-friendly space is created for the neighborhood community. Eco Hanok follows three ecological principles. First of all, using waste or undervalued resources for building, it minimizes negative environmental impact. Secondly, it combines local knowledge with contemporary technology to maximize the quality of lowenergy and low-cost architecture. Thirdly, Eco Hanok sets architectural production within the intricate networks of labor, resource, expert knowledge, and local landscapes. Eco Hanok’s connections to the culture, economy and resources of the Gwangju-Honam region demonstrate the potential for an ecological architecture. Low-carbon materials derived from oyster shells, marine kelp, and earth excavated from construction sites were combined with contemporary construction techniques. Embodying the values of care, repair and regeneration, each architectural, landscape, and interior element is carefully implemented in collaboration with material experts, companies, and craftsmen. Based on an understanding of local culture and resources, Eco Hanok develops architectural materials with ecological, economic, and cultural resilience. Though a small project, it creates communal value that looks to the future of local regeneration.
Assemble + BC Architects&Studies&Materials + Atelier LUMA
The team of Assemble, BC Architects and Atelier LUMA renovated an abandoned hanok in Dongmyung-dong, Gwangju. As the design and material experiments proceeded, the Korean construction and design support team of Stuga House and Urban Society came on board. The inspection by the hanok carpenter revealed that the structure had been compromised by termites. With precise documentation of the building based on a series of 3D scans by Techcapsule, the existing roof, walls and floors were removed following the design guidelines. After removing the existing roof and the laying of new tiles, the vertical and horizontal members of the house were adjusted with new prosthetic elements, bringing stability to the overall structure.
In November 2023, a workshop to make a bench out of shells and recycled aggregates was conducted on site. Concrete from the demolished hanok storage space, cement bricks and tiles, earth from the roof, wood elements were carefully stored on site. The team of BC, LUMA, and students from Chosun University and University of Seoul broke down the demolished concrete and cement elements into aggregates. Hot lime, functioning as a binder, was produced on site through a hydraulic process and then mixed with oyster shells grounded to sand. Similar to rammed earth, the materials of the bench were hand rammed in formwork. The oyster and recycled materials showed out in an intricate pattern of layers.
Brick test materials and samples by Professor Kim Hyeong Ki’s Laboratory on Construction and Building Materials, Chosun University and brick samples by BC Materials. The custom production of oyster shell hot lime - the heating, yielding, and crushing process - was prohibitively expensive. However, by working with Dream Lime, a company that produces disinfectants with cockle shells., cost and time were radically reduced. Lime acquires strength through an extended period of carbonization. This requires standards and methods quite different from the general practice of modern building. As a public facility, Eco Hanok’s bricks must withstand everyday impact. With two divergent industrial ecologies of Korea and Europe in the background, an intense series of experiments and discussions were conducted particularly among BC Materials, Kim Hyeong Ki and Yoo Jungwon. As a result, a small amount of slag, a byproduct of steel manufacturing, was mixed into the brick, securing a mixture and method that allowed long distance logistics and constructability.
In the laboratory, the mixture and production of brick are generally at scales below 10~20kg. However, in the factory, tons of material are used to produce hundreds of bricks in a singular machine setting. Hence, even the smallest error or difference has immense ramifications in time, manpower, and cost. Without time for proper pre-testing, production cycles of hundreds of kilograms of bricks began, resulting in the miscalculation of hydraulic processes of lime. In the first cycle, the bricks from the press blew up and cracked. Fortunately, beyond the bricks that automatically went into the curing chamber, the shell and lime ingredients were retrieved and reused. A second cycle was required to secure all the bricks needed on site. In the hot lime hydraulic process, the purity, production environment, and storage of lime is crucial.
Glaze tests by Atelier LUMA. While most ceramic glazes in Europe are fired at temperatures above 1000 degrees, traditional Korean tiles are fired at relatively lower temperatures. Low temperature glazing at LUMA resulted in glaze separation and incomplete melting. The glaze recipe for the Eco Hanok roof tiles was determined in consultation with Goryung Tile. Using its facilities, Goryung implemented a recipe that brought in bio-circular materials such as abalone and oyster shell lime powder. Based on the two tests conducted by Goryung Tile, the glaze recipe was finalized. While small scale testing was administered in an electric oven, large scale production uses a gas oven with different temperature conditions. During large-scale gas oven production, glaze separated from the earth, dripping down to cause tiles to break as they were taken out of the oven. With the loss of tiles, a second cycle of production was implemented.
Early test samples of glazed recycled Korean tiles by the ceramic artist Kim Siwol. While the roof of the hanok used new tiles, the brick fence and courtyard well employs recycled tiles. Kim Siwol identified the right color and texture by testing different mixtures of transparent glaze, oyster and abalone shell powder, and FeO.
Seaweed panel sample making at the Sejin Plus factory and samples of seaweed panels, glaze, and hanji. Seaweed panels are composed of the simple ingredients of dried kelp and water but require 100 degree temperatures with high pressure mold pressing. Unlike samples produced with laboratory equipment, architectural panels require large machines. The Korean team sought factories that would collaborate but most could not stop their usual production process to accommodate such small scale work. Even under these difficult conditions, Sejin Plus, a company that produces panels through high pressure compressing of recycled fabric, collaborated in the testing process. A new mold to accommodate the smaller size panel was custom made but was damaged because of heat, vapor, and pressure. Furthermore, during the pressurized cooling process, the teflon role was damaged by the heavy and sharp mold. Making a new dedicated press machine was too costly as it was extremely difficult to find the balance of cost and effectiveness.
ried kelp, sea mustard, spirulina mixed in hanji paper. Jangjibang produced a variety of hanji by mixing three types of seaweed into the traditional process. They are pasted on to the repaired doors and windows of the hanok and used in LUMA’s lighting design. Rice husks, traditional natural materials used for insulation, were deployed on the roof and in the walls. Assemble, BC and LUMA initially proposed a mixture of wood chips, earth, and lime for insulation but to reduce roof weight adopted the Korean team’s suggestion to use burnt husk. With this same type of insulation for wall and roof, on-site and pre-fabrication method appropriately applied.
According to their composition, Eco Hanok plasters can be divided into lime and earth. Like bricks, lime plasters use shell-based CaO and an aggregate mixture of crushed oyster shell and sand. For different textures, surfaces may be overlayed with rough 3~4cm size oyster shell aggregates or sponged to accentuate their shine and texture. Earth plasters use either oyster shell aggregates or spirulina to display its natural green dye. Eco Hanok deploys a traditional earthen wall framed with bamboo. Because cracks can occur according to their moisture and mixture, numerous tests were implemented on site to find the right condition.
