This is an empirical study of the rationale the lays behind the decisions made to refurbish or demolish 20th century social mass-housing. The study is based on four case studies located in Edinburgh. From these studies, the decision-making criteria are identified. These fall into three broad categories, which are structural integrity, sociocultural value, and economic practicality. The analysis of these three categories of criteria sheds light on the way in which each is used in justifying the decisions taken. The case studies include 1) the demolition of West Granton Housing Scheme-A; 2) the·. demolition of Tweedsmuir and Grampian Houses; 3) the demolition of Grampian and Cairngorm Houses; and 4) The mixed solution of demolition and refurbishment applied to Ebenezer MacRae's Housing Estates. The study analyses the decision-making process according to three criteria: structural integrity, economic practicality, and sociocultural value. While structural integrity is a precondition for a building's survival and economic viability the fundamental language in which the discussion is conducted, sociocultural value is also of critical significance, as it most clearly indicates the precise and often complex nature of the problem and its solution. The broader context in which these competing agendas operate, however, is political, and as this study makes clear, the ultimate decision and justification on why a building might be demolished or conserved is political.