This paper focuses on the passive design strategies including optimization of day lighting, natural ventilation and Envelope Thermal Transfer Value (ETTV), in North Spine Academic Building (NSAB), a non-residential, lab intensive building located in a university campus in Singapore. In order to evaluate the daylight and natural ventilation performance of this building, extensive modelling and simulation using Ecotect, RADIANCE and Computational Fluid Dynamics (CFD) were carried out as part of the design process. The paper states methods that were considered to achieve low ETTV by optimizing orientation, high performance building materials and window to wall ratio, resulting in significant reduction in accordance with the maximum value as specified in Green Mark Version 4.1. The study investigated common matrix of daylight distributions, illuminance levels and glare analyses within the building. The purpose of this study was to quantify the amount of daylight which can be used to optimize the illuminance levels of the common spaces and if the amount of daylight was sufficient to illuminate the outdoors given its setting in high density boundary conditions. To understand the thermal performance of the naturally lit and ventilated common spaces, the study included the investigation of air velocity in the spaces. Other passive strategies to enhance the envelope performance that could bolster the common goal of maximizing the energy consumption reduction were evaluated using thumb rules, mathematical calculations and desktop studies. The building’s passive features went a long way in reducing its energy consumption and ultimately it being awarded with the country’s top green building rating, which is the “GreenMark Platinum for Non-residential buildings”. This paper demonstrates the implication of undertaking the simulation studies of passive design components of a high performance building whilst illustrating its importance in making appropriate decisions to ensure it achieves high energy efficiency through its operational stage.