Multiple data collection or research methods exist for evaluating library spaces. Faced with numerous choices and limited time for gathering data, it becomes challenging for information professionals to determine the best way to proceed with evaluating their libraries' physical spaces. There is a gap in the literature on best practices for combining and implementing data collection methods to ensure that the results accurately reflect the needs of the population being served. Through a critical analysis of the methods reported in published studies and an examination of the actionable results and lessons learned found in these studies, this article provides a comprehensive overview of the data collection techniques used for space assessments in academic libraries that includes best practices for their implementation. The aim of this critical literature review is to help library professionals undertake the most appropriate research methods for space assessments at their own institutions.