Purpose The average lifetime of a building in Iran is only one-quarter of the reported global average lifespan. A major reason why buildings in Iran have shorter service life is attributed to the inappropriate selection of the facility repair and maintenance (R&M) methods. Hence, selecting the appropriate R&M methods is critical in upholding or even extending the lifespan of the building. The purpose of this paper is to determine the main criteria for selecting the suitable R&M methods of commercial real estate (CRE) in Iran as a major challenge encountered by the Iranian construction industry. Design/methodology/approach The total number of identified criteria (related to the selection of the suitable R&M methods) is 16, which is divided into five clusters (referred as main criteria in this study): human resources; flexibility and technical capability; safety and risk; cost of maintenance; and facilities and technology. To analyze the identified criteria, the expert opinions were collected through both face-to-face interviews and distribution of Delphi survey questionnaires. A total of 12 industrial experts in the construction industry were invited to participate in a Delphi survey to solicit their perceptions and opinions on the identified criteria in this research. Findings The findings indicated that, among the five main criteria, the cost of maintenance is the most important criteria for selecting appropriate R&M methods of CRE in Iran. In addition, the criterion of facilities and technology was recognized as the least important among the main criteria. Originality/value The research, significantly, justified the configuration of non-compliance with the practice and its deliverables and developed a diagnostic study on the grounds of failure in the Iranian construction industry regarding the issues which are threatening the expected and desirable outcomes. The research achievements and suggested effective recommendations can serve as a useful policy and consultative instrument for the relevant stakeholders in the construction industry engaged in building R&M work.