Improving Quality and Sustainability Outcomes in Building Rehabilitation: Concepts, Tools, and a New Assessment Methodology

Pursuing quality and sustainability concerns in construction activities is not new. However, the construction sector continues to face criticism for the outcome of many interventions, and significant progress is still required to realise both objectives. This is particularly pressing in sectors essential for quality of life and wellbeing, such as housing, and in areas frequently neglected in research and practice, such as existing buildings. This paper provides insights into the assessment of quality and sustainability in existing buildings, clarifying these concerns, exploring their interrelationship, emphasising the critical role of the design phase, and synthesising relevant methodologies focused on each objective. Furthermore, a novel methodology is proposed to minimise the risk of poor quality in building rehabilitation processes. Methodologically, the paper includes a review of concepts associated with quality and sustainability in building rehabilitation, a synthesis of existing evaluation tools and methods, and the development of the proposed methodology. The main findings include a definition of construction quality, identification of strong correlations between quality and sustainability, and the recognition that using accessible, flexible, and collaborative tools during the design phase is crucial to achieving both objectives, especially in the context of existing buildings, where practical and operational outcomes remain limited.