Low-carbon cities have been the favorite subject of many societies with the aim of making a sustainable environment for life. The purpose of this study was to develop a conceptualized model of low-carbon city with a sustainable approach by applying life-cycle cost analysis as the methodology with secondary data from Iranian national report to the United Nations framework convention on climate change. This study attempts to examine the factors affecting the production and increase in carbon emission in urban areas and also provides some solutions to solve these problems and create low-carbon urban areas in order to promote environmental quality with a sustainable development approach. Then, some tools and methods are developed to improve the analytical rigor associated with climate action plans. With a focus on non-behavioral items, the cost and effectiveness of more than 30 action items are quantified. Finally, the scenario analysis was used to evaluate the cost and efficiency of various program designs. Results indicate that greenhouse gases mitigation takes remarkable initial investments. This cost differs from $1 to $70 M for each percent of reduction depending on scale and scope of the program. However, long-term cost savings are considerable if the program is properly designed, with the 20-year return period for different climate action plans, exceeding 100%.