The construction industry faces the critical challenge of balancing project time, cost, and carbon emissions to achieve sustainable development. This study introduces a Time–Cost–Carbon Emission Trade-Off (TCCET) model, optimized using the Non-dominated Sorting Genetic Algorithm III (NSGA-III), to address these conflicting objectives. The TCCET model evaluates various execution modes for construction activities, such as groundwork, excavation, footing, formwork, and finishing, taking into account their respective impacts on time, budget, and carbon emissions. By applying NSGA-III, the model generates a set of Pareto-optimal solutions, offering decision-makers diverse trade-offs among these objectives. A practical case study demonstrates the model’s effectiveness in real-world scenarios, yielding flexible and efficient solutions that support informed decision-making in construction management. Comparative analysis with existing optimization models and sensitivity analysis highlight the superior performance of NSGA-III in addressing time, cost, and environmental impact simultaneously. This study’s findings emphasize the potential of NSGA-III to guide sustainable construction practices, significantly reducing environmental footprints without compromising project timelines or costs. The developed framework aligns with global sustainable development goals, providing valuable insights for the construction industry’s transition to sustainable practices.