Energy Efficiency in Existing Buildings that were Constructed before the Green Building Agenda was Mooted

The article is based on a study that investigated the challenges and strategies in retrofitting older buildings in Mutare City, Zimbabwe, to improve their energy efficiency and sustainability. The existing buildings significantly account for global energy consumption and carbon emissions, thereby contributing to rapid climate change and its associated problems. This necessitates urgent action to enhance energy efficiency in existing buildings in many cities, particularly those built before the Green Building Agenda through green retrofitting. Several developed countries have made strides in retrofitting existing buildings in urban areas to achieve the goals of green retrofit designs. Despite these successes in developed countries, the implementation of retrofitting has remained slow in developing countries due to several barriers, with significant implications for addressing climate challenge issues. This article examines the challenges to implementing energy-efficient technologies in these structures and explores strategies which have improved energy efficiency in similar situations. The qualitative research approach was employed to guide the study using the case study research design. Participants were selected through non-probability sampling techniques. The data were collected through the interview and observation methods. It was analysed through thematic analysis and presented textually through narrative description. Findings reveal that the barriers to improving energy efficiency in old buildings in Mutare are socioeconomic, technical and regulatory factors. It is also revealed that a multiplicity of strategies can be used to address challenges impeding green retrofitting of old buildings in Mutare. Conclusively, it emerged that addressing these barriers is a necessity and requires a multifaceted approach. The recommendation involves adopting a multifaceted approach to tackle the challenges affecting green retrofitting to optimise the energy performance of the existing building stock.