ASSESSING THE BENEFITS OF LOW-CARBON RETROFIT DESIGN: A CASE STUDY ON OPTIMIZED BUILDING PERFORMANCE OF A RETROFITTED BUILDING

The built environment is a major contributor to global CO₂ emissions, with existing building stocks accounting for a significant share throughout their life cycle stages. In response, there is growing global attention to retrofitting existing buildings to reduce energy consumption and carbon emissions. A well-structured retrofitting strategy can offer a practical solution, providing reductions in emissions as well as cost, comfort, and environmental benefits. This paper focuses on a commercially initiated retrofit project in Melbourne, Australia, demonstrating its process and presenting appropriate recommendations for retrofits in a similar context. It evaluates the effectiveness of a low-carbon retrofit by comparing the retrofitted performance with the actual performance of the building. The case study is 182 Capel Street, a 1,600-square-meter commercial office building in North Melbourne, Australia, known for its retrofitted low-carbon design (LCD) strategies. Key retrofitted features include a solar-responsive building envelop, insulation, glazing, HVAC systems, and recycled materials. This paper provides a systematic approach to assessing how the retrofitted building envelop features affect energy conservation, with a detailed energy distribution analysis. The study is carried out by simulating the implemented retrofit scenarios using DesignBuilder® software, focusing on improved daylighting, and thermal comfort. Based on a summary of the implemented strategies and post-occupancy evaluation data, a comparative analysis demonstrates how the building benefits from low-carbon retrofitting in terms of energy consumption and overall performance. The findings reveal that the implemented retrofitting strategies have significantly improved the building's energy performance, leading to a 30% reduction in annual mechanical energy consumption and a 40% decrease in lighting energy use.