Retail stores are amongst the building typologies with the highest carbon (CI) and energy intensities (EI). However, previous studies have only explored best practice EI of food and non-food retailers, without identifying best practice CI threshold values. This paper presents a five-step analysis of CI and EI amongst the highest revenue retailers, benchmarking best and worst performing CI and EI retailers, analysing their nationality, performing a content analysis on their CSR reports and comparing results in terms of differentiation policies, strategies and building practices that can lead to increased environmental performance. Combined CI and EI best practice threshold values were found simultaneously under 346 kWh/m²/y and 115 kg CO₂eq/m²/y for food retailers and under 146 kWh/m²/y and 70 kg CO₂eq/m²/y for non-food retailers. In terms of policy, best-performing retailers shared a strong top-down management commitment towards sustainability across all business areas (p = 0.04) and an increased use of referential reporting standards, particularly of GRI standards (p = 0.05) and of the GHG protocol (p = 0.01). In terms of strategy, they established ambitious energy goals, such becoming 100% supplied by renewable energy (p = 0.05) or carbon neutral by 2020. As for building practice, LED and photovoltaic technology were the most popular high-performance solutions, but only the use of natural refrigerants (p = 0.001) and gas transfer to CO₂ (p = 0.0007) were related to best-performing practice. The variability of CI and EI found in this study shows that it is already possible to reduce the retail sector’s contribution to global GHG emissions considerably. The proposed best practice CI and EI reference levels, linked to corporate policy, strategy and building practice, are useful new tools for retail energy-management, which can further promote sustainability in retail buildings, thus allowing a deeper understanding of how to decarbonize the retail building sector.