India's first 765 kV Gas Insulated Substation in Pune is part of the transmission system associated with Krishnapatinam UMPP, to connect 765 kV Solapur S/S to the existing 400 kV Pune-Parli Substations to strengthen power distribution in western India. With 3448 m of gas insulated bus ducts in a single substation, it is the first ever steel structured building to house a 400 kV and 765 kV GIS and the first ever with a one-and-a-half circuit breaker scheme in a substation in India. We successfully installed 7 bays of 765 kV GIS, 11 bays of 400 kV GIS, 660 MT of structural steel and 720 MT of galvanized steel structure.