3D printing of a multi-performative building envelope: Assessment of air permeability, water tightness, wind loads, and impact resistance

This study investigated the 3D printing feasibility of mono-material facade panels with recycled thermoplastic. The design had integrated performance parameters, namely air permeability, water tightness, resistance to wind loads, and impact resistance, and fabrication parameters in a computational iterative process to inform the geometry topology. The fabrication parameters were integrated and evaluated for geometry accuracy, print path accuracy of 5 mm length, overhang higher than 45°, inner layer adhesion, and adhesion to the print bed. Two panels, measuring 1.6-m length and 2-m height, and six connections were fabricated and evaluated in a standardized facade testing rig. The air permeability displayed a larger than 1.5 m3/m2·h permissible Class 1 value due to air gaps in the manufactured panels. The same gaps that occurred during the fabrication process permitted water flow in both panels after 7 min of testing. The panels passed standardized serviceability and safety standards for wind load resistance and achieved a maximum E5 class for impact resistance. The structural strength values were 1500 Pa for serviceability, 2250 Pa for safety load, and 3262 Pa for breaking load. These findings demonstrated that 3D-printed geometries have a high potential to facilitate sustainable design strategies by integrating multiple performances within a mono-material building envelope.