Additively Manufactured Ceramic Façades for Biodiversity and Climatic Performance Integration: A Full-Scale Case Study

This paper presents a multiscale design-to-production workflow for additively manufactured ceramic façade elements that integrate biodiversity-supporting nesting sites and climate-responsive surface geometries, while remaining compatible with standard ventilated façade substructures. The research combines (i) material and process optimisation for extrusion-based clay 3D-printing, (ii) fabrication-aware computational design from building scale to printing path scale, and (iii) standards-referenced mechanical assessment. Material development focused on mitigating shrinkage-induced deformation and cracking by optimising clay–grog–water–additive ratios and controlling drying conditions. An optimised clay mixture, in combination with a material-informed printing-path strategy, reduced the root mean square (RMS) deviation to as low as 1.56 mm (49%) from the as-planned geometry compared to elements with unoptimised configurations. Deformation was quantified using 3D scanning and target-actual deviation analysis, with attention to rear-surface planarity to ensure mounting-system fit. Controlled high-humidity drying reduced cracking rates to below 10% in optimised geometries. Mechanical performance was evaluated using an adapted three-point bending test methodology based on DIN EN 14411 and DIN EN ISO 10545-4. In the optimised material-process configuration used for the prototype, specimens achieved average modulus-of-rupture values of 10 N/mm² parallel to print layers (and up to ~25 N/mm² perpendicular), primarily complying with façade-tile requirements (≥8 N/mm²), with breaking loads above the 600 N threshold. The workflow was verified through production of a 12 m² façade installation in Munich, integrating species-specific nesting cavities and site-specific self-shading elements, built into a standard ventilated façade substructure. First in-situ thermal measurements recorded surface temperatures of the 3D-printed ceramic façade up to 16 °C lower than a flat rendered External Thermal Insulation Composite System (ETICS) reference façade under comparable solar exposure conditions; internal nesting cavity temperatures did not exceed 34 °C during peak conditions. The prototype serves as a long-term testbed for ecological occupancy monitoring and further microclimatic performance assessment.