The paper is based on the experience of working with the public works departments (PWDs) and other state departments responsible for the construction of public buildings in Karnataka, Rajasthan, and Andhra Pradesh. State PWDs and other similar government departments responsible for the construction of public buildings in the states have an important role not only in making the public buildings energy-efficient and thermally comfortable but also in the implementation of the Energy Conservation Building Code (ECBC). The paper presents the various approaches and lessons gained in this process, along with ideas for more effective engagement with the state PWDs to mainstream energy-efficient building design practices within the department.