In 2018, greenhouse gas (GHG) emissions from shipping were estimated to account for 2.9% of global emissions, with projections indicating an increase of up to 44% by 2050 under various long-term energy and economic scenarios. In response, the International Maritime Organization (IMO) has set ambitious targets to reduce carbon intensity by at least 40% by 2030 and achieve net-zero GHG emissions around 2050. This research explores the potential and implications of integrating life cycle environmental performance evaluations into early-stage ship design, moving beyond the traditional “tank-to-wake” focus to encompass the entire life cycle of a vessel. Incorporating Life Cycle Assessments (LCA) into the design stage promises to optimize vessel design by addressing environmental and economic impacts across its full lifecycle, from construction to decommissioning. The primary objective of this report is to investigate the extent to which life cycle assessment optimization, based on cost and environmental impact, can be performed and implemented in the conceptual ship design of complex vessels, and to assess how it can support the development of new designs. This study presents an analysis of the lifecycle stages of ships and introduces Ulstein Design & Solutions B.V.’s innovative design tool, Blended. Through an extensive review of life cycle thinking methods, material and energy flow analyses, industrial ecology practices, and socio-economic impact assessments, the research establishes criteria for evaluating the applicability of these methodologies. A trade-off analysis guides the selection of an appropriate approach, leading to the development of a novel method to integrate life cycle assessments into the Blended Design tool. Key outcomes of the research include the identification of relevant life cycle assessment methodologies and their applicability to early-stage ship design. Additionally, an approach has been developed to integrate both cost- and GHG-emissions-based life cycle assessments into Blended, focusing on the shipbuilding and decommissioning phases. Furthermore, the study demonstrates how life cycle assessment integration can influence early design decisions, particularly by addressing the environmental and economic trade-offs that arise during construction and maintenance. The study emphasizes the importance of addressing lifecycle impacts in early-stage ship design to prevent burden shifting between lifecycle phases. It also highlights the need for robust data collection and the development of performance indicators tailored to specific ship designs to enable reliable assessments, despite the limited information available at the early stages of design. In conclusion, this research advances the understanding of how LCA can be applied in conceptual ship design to meet sustainability objectives. By enabling full lifecycle optimization within the Blended Design tool, it offers a pathway to creating vessel designs that balance environmental responsibility with economic viability, contributing to the maritime industry’s efforts to meet international decarbonization targets.