At present, debates addressing climate change, fossil fuel depletion, and energy saving highlight the need for a more sustainable built environment to reduce energy consumption and emission trends in the building sector. With a primary focus on commercial buildings in Sri Lanka, where Heating Ventilation and Air Conditioning (HVAC) systems account for a significant portion of electricity usage, this research investigates into the underexplored area of airside efficiency strategies. For this purpose, a comprehensive literature synthesis was conducted, and a qualitative research approach using a semi-structured interview survey was conducted targeting 17 experts. The collected data was then analysed using content analysis. The findings of the research revealed 17 strategies under 3 categories namely, Air Handling Unit (AHU) optimisation, system design and layout optimisation, and cooling system optimisation. Key strategies identified are, the installation of efficient AHU filters, Variable Air Volume (VAV) system implementation, advanced controls and automation, reduction of coil losses, Variable Speed Drive (VSDs) installation, a control system addressing varying loads, night purging and air distribution and balancing. The knowledge gathered through this study can be used by respective industry professionals to enhance HVAC energy performance, while it will also help the academia to research more on this sub-branch of HVAC system in the Sri Lankan context