Air-conditioning and mechanical ventilation (ACMV) systems account for major electrical demand within buildings. These systems have large thermal time constant and can be utilized as thermal energy storage. This paper is focused on participation of commercial buildings in Singapore’s Demand Response (DR) programme by adjusting electricity demand of ACMV systems for financial incentive and power grid benefits. A novel Transactive Energy-based virtual market is proposed for a building where multiple zone agents transact to purchase conditioned-air from central ACMV system. These zone agents consider forecasts of occupancy and outdoor temperatures to submit bids for conditioned-air corresponding to increasing electricity market prices, using a novel dynamic programming (DP) approach to utilize the temporal flexibility in cooling demand through pre-cooling. ACMV electricity demand bid is calculated based on net conditioned-air bids by using existing accurate building models in whole-building energy modeling (BEM) platforms corresponding to increasing electricity prices for submission to Singapore’s DR market. Case studies are performed in MATLAB-EnergyPlus co-simulation environment on a benchmark five zone building model. Results show that the proposed control is effective in providing DR according to real Singapore market price signals while respecting occupants’ thermal comfort preferences and incentive from DR market participation can be lucrative.