Energy Efficient residential buildings are being promoted in India by Bureau of Energy Efficiency (BEE) in response to India’s National Action Plan on Climate Change (NAPCC 2008). Energy conservation Building code for residential buildings (ECBC-R), also known as Eco Niwas Samhita (ENS) was developed to set minimum building envelope performance standards for controlling heat gains/loss, natural ventilation, and daylight. Its compliance calculation involves simple-to-apply but lengthy and tedious process of deriving required data from a given design. The advanced online and offline optimisation tool of ENS is available but it does not involve features to iterate through building form variation. Hence, there was a need to develop a tool that can help the designers to optimise all parameters of the design to achieve ENS compliant design. This paper introduces and evaluates a parametric 3D modeling workflow to automate the collection and calculation of data required for checking ENS code compliance. The workflow involves use of Rhinoceros, Grasshopper3D, and Ladybug tools for generating and evaluating the design options iteratively. A typical eight story residential apartment building design having 4 dwelling units of 40 sq. m. per floor was optimised in this study. The resulting grashopper3D script was used to iteratively evaluate multiple variations of the building form. The automatic compliance feedback given by this script helped in optimising the building form to achieve ENS code compliance in a matter of minutes.