The use of renewable energies, especially in metropolises has led to a reduction in environmental pollution and greater access to clean, renewable and sustainable energy. This paper evaluates the effectiveness of a national plan adopted by the Tehran city council for reducing air pollutions. This plan is designed to increase the share of renewable energies in residential buildings. This study assumes that the extended renewable share is supplied by ground source heat pump (GSHP) systems. The number of Residential Building Permits (RBPs) issued by the city government is predicted in the next five years. Then the effects of using GSHPs on the amount of consumed electricity power and Gas are estimated by considering the policies intended for using GSHPs in Tehran. Finally, the reduction amount of air pollutants is calculated by considering the obtained results from the previous step. The reduction in gas consumption is estimated to be 4,810,848 m3. As a result of this reduction, 9429 tons of CO2, 201 kg of SOx, and 10 tons of NOx are prevented from releasing into the atmosphere. The increased amount of electricity power from running GSHPs in the residential buildings is predicted to be 11,182,543 kWh. The natural gas consumption savings is nearly 50% regarding using combined cycle power plants to generate electricity. The results demonstrated that the plan leads to decrease the emission of CO2 and SOx, and increases in NOx emissions when the excess electricity is supplied by the steam turbine, gas turbine, and combined cycle power plants.