Reducing energy consumption in existing and new buildings in an economical fashion, while preserving health, productive, and good indoor air quality (IAQ) is the main concern for a country such as Kuwait. In summer, Kuwait reports having months with daily maximum temperatures averaging above 46 ºC, it's well beyond the hottest weather ever experienced in many other countries. Kuwait is facing an increase in energy consumption and the country is struggling to increase the electricity generating capacity in order to meet the high demand. The main objective of this work is to optimize building envelopes, windows and fenestration systems and energy efficiency ratio (EER) in order to decrease energy consumption. Another aim is to come up with optimum design for a residential building in Kuwait. The optimization technique uses Kuwait energy code as a basis, the multi-objective function is to minimize energy consumption and the cost of building materials. This approach is suitable for determination of optimum energy saving parameters in the residential building.Energy consumption of a Kuwaiti house was modeled with an energy simulation software.