Sustainability assessment of resource recovery from waste is an important prerequisite for informed and sound decision-making. Life Cycle Sustainability Assessment (LCSA) has been developed to support this process, yet its use is still constrained by the difficulty of identifying the most relevant impact parameters. This paper, seeks to inform LCSA for resource recovery from waste based on a parameter identification approach that uses the political, economic, social, technological, environmental and legal (PESTEL) analysis. The novelty of this approach lies in the structured conceptualisation of the resource recovery system and the context within which decisions are made. The anaerobic digestion of source-separated food waste in the UK is used as a case study to trial and demonstrate the approach. Findings suggest that a conceptual, qualitative analysis, although limited in its scope due to the lack of quantitative components, is suitable in integrating different parameters, allowing for a holistic conceptualisation of the system and capturing important issues that could be easily overlooked. This type of analysis can summarise the key interdependencies, contrast the trade-offs and provide a wider understanding of the political and legal context within which the system operates, all important in extending the implementation of LCSA towards the right direction.