Integrating Green Retrofitting of Existing Buildings with Concurrent Restoration of Surrounding Degraded Ecosystems toward Carbon Neutrality

Retrofitting existing buildings and restoring adjacent degraded ecosystems can significantly reduce environmental burdens through linked changes in energy, water, materials, and land management practices. Their simultaneous implementation, however, does not inherently guarantee additional carbon benefits. This paper develops an integrated assessment framework that combines technology selection with separate accounting for emissions, additional ecological removals, and ecosystem recovery. A structured narrative synthesis informs a four-alternative comparison of continued operation, building retrofit, ecological restoration, and integrated strategy. An explicitly hypothetical thirty-year example demonstrates the calculation methodology and tests its sensitivity. Within the modeled boundary, the integrated alternative achieves a net carbon reduction of 8,336 t CO2e relative to continued operation, compared with 8,226 t from building measures and 66 t from restoration alone. The resulting interaction benefit is only 44 t, because shared construction, maintenance, and replacement savings are partly offset by overlapping energy savings. An additional annual electricity demand of 5 MWh reverses this interaction. The example therefore supports testing integration rather than presuming synergy. The proposed implementation sequence connects structural and contamination assessment, envelope and heating improvements, water management, habitat recovery, and monitoring. Progress toward carbon neutrality requires sustained demand reduction and transparent treatment of residual emissions; furthermore, ecological recovery must also satisfy independently defined criteria for habitat, soil, water, and long-term maintenance to ensure comprehensive environmental benefits.