International regulations on greenhouse gas (GHG) emissions as well as strong market demand for zero-emission transport call for a radical change in the shipping industry. To effectively respond to climate challenges, we must turn to emission-free energy sources and innovative ship design solutions. One such promising zero-emission propulsion assistance system for shipping is wind propulsion. Building on the findings of our previous research on the effects of wind propulsion on a VLCC, we introduce herein more advanced modeling and assessment methods and tools to further refine the optimization process. The objective is to identify optimal VLCC designs that integrate wing sails, while maintaining high operational performance and complying with existing maritime regulations. An optimization framework has been developed and is herein utilized to optimize for energy efficiency and low freight rates, while ensuring compliance with multiple design and regulatory requirements. Obtained results indicate significant reductions in fuel consumption and GHG emissions by use of wing sails.