In this study, the demand of the Iran’s energy carriers is analyzed and modeled for the country’s largest consumer, buildings and related industries, in the status quo and future perspective. To this objective, the building sector is divided into two sections: household section (residential buildings) and services (business-office and service buildings) according to the ISIC classification that each of these sections is divided into sub-sections. In addition, building-related industries include some non-metallic minerals and basic metals industries. Regarding to scenario-based energy planning helps to increase the understanding of different probabilities in the future. The future outlook for the system is modeled with the horizon of 2035 with the LEAP modeling tool in the “reference” scenario, indicating the sustainability of the existing energy system in the future. The results of modeling indicate an increasing demand for energy as expected that energy demand carriers in buildings and related industries from 559.8 million barrels in 2014 reach up to 1040.6 million barrels of crude oil equivalents in 2035. Therefore, in order to reduce energy consumption, solutions are modeled and analyzed according to the scenarios for “Improvement of energy consumption in buildings and related industries”, then the greenhouse gas emissions and their environmental effects are investigated.