Shifting light and shadow under the 45 degree rotated hyperbolic roof
A residential project pushing the expressive and technical limits of timber construction has been completed in Taiwan. Named Our Forest, the house sits beneath a vast roof measuring 16 meters wide and 18 meters long, combining CLT (cross-laminated timber) and GLT (glued-laminated timber) to enhance structural performance while redefining domestic architectural aesthetics. The hyperbolic roof, rotated 45 degrees, generates shifting contours that cast dynamic patterns of light and shadow throughout the interior. With 396 curved members and thousands of precisely assembled joints, the structure demonstrates how timber design can surpass long-held limitations. Using cypress from Kagoshima, Japan, the project also reduces carbon emissions by approximately 700 tons compared to steel, reinforcing its sustainability. By emphasizing both structural innovation and material sensibility, the house offers a daily experience reminiscent of living beneath a forest canopy.
The timber roof Is the central element shaping both the building‘s form and its interior spaces. Set diagonally, the hyperbolic canopy creates varying light patterns between the floor plan and roof structure, filling the single volume with a diversity of environments. The combination of CLT and GLT enables long spans and complex curvatures that are difficult to achieve with conventional timber construction. At the outer edges, the column-free roof extends outward to form shaded transitional zones resembling deep eaves, naturally blurring the boundary between interior and exterior. The varying roof heights counteract the compact scale of the single-story layout, while the exposed timber framework revealed between levels adds spatial depth.
Each timber member of the roof has a unique curvature. To realize this complex geometry, the structure was prefabricated using metal joints, which shortened on-site construction time and simplified the process. The lightweight nature of the timber system also reduces environmental impact and logistical demands. The natural scent of cypress brings calm to daily life, enhancing well-being in a way reminiscent of forest bathing. By overcoming the notion that timber structures are limited in scale or form, the house demonstrates new architectural possibilities while harmoniously integrating sustainability and aesthetic value into everyday living.
Project: Our Forest / Location: Yunlin, Taiwan / Architect: CTAA Architects Lab (Cha Shao Yu) / Project team: Tseng Yu Han / Structural engineer: HONG MAI Engineering Consultant Co., Ltd. / General contractor: FON JENG Co., Ltd. / Wood supplier: Yamasa Mokuzai Co.,Ltd. / MEP: CTAA Architects Lab / Environmental sustainability: CTAA Architects Lab / Use: residential architecture / Site area: 760m² / Gross floor area: 404.76m² / Completion: 2025 / Photograph: ©Studiomillspace (courtesy of the architect)
