Carbon, indoor air, energy and financial benefits of coupled ventilation upgrade and enhanced rooftop garden installation: An interdisciplinary climate mitigation approach

•Indoor CO2 exceeded 1000 ppm 33% of the time and ventilation rates were below 7 L/s.•Increasing ventilation increased CO2 emissions, energy, and costs between 1 and 4%.•Rooftop gardens always counterbalanced increased CO2 emissions, energy, and costs.•Enhancing plant growth increases CO2 emissions benefits by an additional 23%.