The sustainability of retail spaces remains underexplored compared to residential buildings, despite their significant environmental, economic, and social impacts. This study develops a comprehensive methodology for evaluating and comparing retail renovation models through a Life Cycle Sustainability Assessment (LCSA) framework, aligned with international building sustainability standards. Three models—General Model (GM), Quick Renewal (QR), and Pop-Up (PU)—were analysed across the full life cycle (creation, use, and end-of-life phases), using standardized tools and databases such as CYPE “Arquímedes,” CE3X, and SimaPro. Impact indicators considered were Global Warming Potential (GWP), Global Cost (GC), and Labour Time (LT). A functional unit (m2/year) was defined to incorporate life cycle duration into the comparison, addressing the successive renovation cycles typical of commercial spaces. This unit enabled the normalization of results and the calculation of an aggregated sustainability index across four weighting scenarios prioritizing different sustainability dimensions. Findings indicate that while GM delivers full renovation aligned with branding, it generates the highest impacts; QR offers moderate impacts with potential for impact reduction through reuse strategies; and PU, although appearing less impactful over a single cycle, shows significant cumulative impacts over time. The study underscores the critical role of time in sustainability assessment and highlights the potential of strategic design and material durability to enhance sustainability performance. This replicable methodology bridges an existing gap in retail sustainability evaluation and provides a holistic framework adaptable to other building typologies.