This document describes the passive cooling design of an auditorium building at PERI Institute of Technology in Chennai, India. Key aspects of the passive cooling design include natural ventilation, minimizing heat gain through good shading and double glazing, and using a green roof to provide insulation. The auditorium is designed to seat 3000 people and provide good acoustics for lectures and presentations. Structural elements like the slab, beams, columns, and footing are manually designed according to Indian codes. Details of the structural design of these elements, such as load calculations, reinforcement requirements, and dimensional checks are provided. Diagrams of the reinforcement for the slab, beams, and plan are also included.