This study introduced a data-driven framework for the design, control, and resilience assessment of a low-temperature radiant heating and high-temperature cooling system in a heritage commercial building connected to a district heating network. The solution integrates a modular underfloor heating and cooling system with return-flow district heating, a reversible heat pump, and a building-integrated photovoltaic system. Circuit-level modeling and validation against manufacturer data show uniform thermal output with a mean absolute percentage error below 4%. Resilience is assessed under cold-wave and heat-wave scenarios using a validated simulation model. Control strategies include preconditioning with 1–5 h offsets, which exploit building thermal inertia to maintain comfort during extreme events. Results demonstrate how a data-driven approach enables accurate hydraulic and thermal design, effective renewable integration, and scenario-based resilience analysis in a constrained heritage context.