Deriving Priorities for Energy Savings Rates and Construction Cost Simple Payback Periods According to Green Remodeling Measures in Public Health Centers

Purpose: The global average temperature has risen by over 1℃ in the past century as atmospheric CO 2 concentrations increased from about 280 ppm in the pre-industrial era to nearly 400 ppm today. In response, many countries have implemented carbon-neutral strategies centered on the building sector. Korea has declared carbon neutrality by 2050 and aims to cut national greenhouse-gas emissions by 40% by 2030 (from 2018 levels), including a 32.8% reduction in the building sector. To achieve this, the government promotes green remodeling of existing public buildings. However, implementation remains challenging due to variations in cost, energy performance, and payback across technologies. This study analyzes the energy performance and economic feasibility of green remodeling technology combinations for public health centers to identify optimal strategies at the early design stage. Method: Using survey data from 51 buildings (10–20 years old), 25 combinations integrating passive (insulation, windows), active (equipment, boilers, ventilation), and renewable (PV) technologies were simulated with ECO2-OD. Result: The window+heat-source system+PV (Comb. 18) showed the best balance between performance and cost, while insulation+window+equipment+PV (Comb. 22) achieved the highest energy savings but a longer payback due to higher initial costs.