Resonant Metamaterial Architectures for Smart Building Envelopes: From Electromagnetic Sensing and Energy Harvesting to Programmable Metasurfaces

Resonant electromagnetic metamaterials and metasurfaces are being investigated for sensing, radio-frequency energy harvesting, selective shielding, and wavefront control in buildings. This review examines these functions in relation to the materials, fabrication methods, and operating conditions relevant to building envelopes. The discussion distinguishes numerical predictions, experimental component demonstrations, and integrated prototypes, with particular attention paid to the evidence required for building-scale deployment. Conductor losses, substrate variability, environmental drift, angular and polarisation dependence, and the control requirements of programmable surfaces are considered alongside electromagnetic performance. Additive manufacturing, CNC engraving, inkjet printing, spray deposition, nanoimprinting, and laser processing are compared in terms of their capabilities and limitations. Existing building-product, fire-safety, and electromagnetic requirements provide part of the assessment framework, while application-specific qualification remains necessary for metamaterial-enabled components. The review identifies the comparative measurements and system-level validation needed to determine where resonant structuring offers an advantage over established building technologies.