Passive measures to tackle increasing energy demands of modern buildings are aimed to generate energy from the roof or the ground beneath and by improving insulation to isolate indoors and outdoors. The author targets the opaque facade sections of a building to develop an active panel to exchange solar thermal energy with his project THERM_VENATION- Active Thermal Façade Venation. It is a project dealing with designing and fabrication of a twin-wall concrete façade panel with heat exchange tubular network embedded within it inspired by the leaf venation, which by actively exchanging fluid between the two panels conditions the indoor temperature, in the extreme composite climate of Delhi, India. This project follows a design through research methodology with computation tools, boundary conditions, material properties and the method of fabrication guiding the design and its result.