CNC-knitted textiles for adaptive building envelopes: material programming and interdisciplinary design strategies

CNC-knitted textiles present emerging opportunities for adaptive building envelopes due to their programmability at the stitch level and their capacity to generate diverse material behaviours. While knitting enables radical transformations in geometry and expression directly within the textile structure, this potential remains largely unexplored at architectural scale. This study investigates how these qualities can support environmentally responsive faades tailored to project-specific and local performance needs. Through a research-by-design methodology, the project integrates architectural, textile, and engineering expertise to develop rib-based CNC-knitted structures using sustainable mono-material yarns intended as alternatives to fossil-fuel-based elastomeric components. Iterative prototyping was employed to analyse reversible elasticity, dual-state behaviours, and fabrication strategies enabled by seamless, waste-minimal CNC-knitting. The novel architectural surfaces are implemented in an active bending structure and enable significant geometric change without conventional hinges or composite layering, supporting expressive material responses aligned with local environmental conditions. The Manta-Ray prototype exemplifies this capacity: it shows how knitted structures can function as adaptive faade elements, achieving large-scale shape change for solar shading with only minimal actuation input. The study identifies the technical, material, and collaborative frameworks necessary to transition CNC-knitted textiles from experimental prototypes toward deployable faade systems. Their inherent adaptiveness, material efficiency, and architectural expressiveness position CNC-knitted textiles as a promising strategy for responsive and sustainable building envelope design.