Retrofitting existing buildings with BMS systems is an indispensable step towards meeting carbon targets. By optimising energy efficiency, integrating renewable energy, and enabling intelligent building management, BMS empowers buildings to reduce their carbon footprint significantly. Through retrofitting with BMS systems, buildings can contribute to a sustainable, low-carbon future while enjoying benefits such as energy savings and improved occupant comfort. It is essential for stakeholders to recognise the value of retrofitting and embrace BMS solutions as a catalyst for change. Together, we can make a substantial impact in the fight against climate change and work towards a more sustainable and resilient built environment.