This study simulates various environmental regulation scenarios for fine particulate matter (PM2.5) caused by the massive use of firewood for residential heating. Specifically, an optimization model calibrated with microdata is proposed to minimize the total costs of meeting an aggregate emissions reduction target, considering all urban areas of central-southern Chile where an Atmospheric Decontamination Plan (PDA) has been implemented. The results show that the total compliance cost in each urban area with PDA grows at increasing rates when the targets are more demanding. The cost-effectiveness indicators vary between 1.1 and 1.8 thousand dollars for a target of 20 % but rise to values between 3.7 and 7.6 thousand dollars for a target of 99 %. The lower indicators are observed in areas with greater firewood consumption. The preferred options for households to replace their current firewood heaters are pellet heaters and hot/cold inverter air conditioning units. Surprisingly, thermal improvement on dwellings is not economically attractive. Finally, it is concluded that achieving reduction targets close to 80 % would be possible if only 56 % of households replace their firewood heaters based on the costeffectiveness criteria, also obtaining co-benefits from lower black carbon and greenhouse gas emissions.