Buildings are a crucial last mile element of the smart grid of the future. Demand flexibility offered by buildings and appliances is an untapped opportunity for the distribution utilities. Grid-Interactive Net Zero Energy Buildings (G-NZEBs) are highly energy-efficient, grid-connected buildings that meet their energy needs through renewable means, while maintaining a two-way communication with the grid to balance demand with electricity supply. The ZerO-In Dialogue Series will expand the discussion from a singular net zero building to high performing, smart, connected, and flexible communities and cities moving towards net zero emissions. The first dialogue of this series introduces the concept of Grid Interactive Net Zero Energy Buildings; – what they are and why they are important.