A processor implemented method for maximizing space utilization in a building, the method comprising: dynamically receiving, via a one or more hardware processors, using a thermodynamics model providing spatio-temporal dynamics of thermal and bio-safety properties of the building, a plurality of thermal signals using a plurality of sensors positioned in the building, wherein an open plan space of the building is segmented into equally spaced cells comprising a plurality of infected cells and a plurality of uninfected cells; determining, via the one or more hardware processors, using an optimal occupancy placement technique, maximum allowable occupant count in the plurality of uninfected cells based on (i) a plurality of parameters comprising an infection probability, an exposure, and a total number of segmented cells of the open plan space, (ii) a temperature and a humidity obtained from the plurality of thermal signals (iii) an estimated amount of viral particles concentration shed by a plurality of infected subjects at one or more of equally spaced cells in a preoccupied open plan space of the building, and (iv) a susceptible probability of an uninfected subject infected at predefined exposure time, and (v) a one or more neighboring cells adjoining the infected cells; and estimating, via the one or more hardware processors, using a joint actuator control technique, energy consumed by an HVAC (heating, ventilation and air conditioning) controller for the building based on the determined maximum allowable occupant count, wherein the HVAC controller comprises a plurality of actuators in the open plan space of the building based on (i) the HVAC controller energy computed using a chiller energy and an actuator supply fan energy, (ii) a predefined temperature range, (iii) a cooling load of each actuator computed using a mass flow rate of the corresponding actuators, an enthalpy of actuator supply, and return air, and (iv) maximum average cell temperature range, and minimizing the HVAC controller energy consumption after considering the thermal and bio-safety properties if the actual occupant count required is less than an optimal maximum allowable occupant count. dynamically receiving, via a one or more hardware processors, using a thermodynamics model providing spatio-temporal dynamics of thermal and bio-safety properties of the building, a plurality of thermal signals using a plurality of sensors positioned in the building, wherein an open plan space of the building is segmented into equally spaced cells comprising a plurality of infected cells and a plurality of uninfected cells; determining, via the one or more hardware processors, using an optimal occupancy placement technique, maximum allowable occupant count in the plurality of uninfected cells based on (i) a plurality of parameters comprising an infection probability, an exposure, and a total number of segmented cells of the open plan space, (ii) a temperature and a humidity obtained from the plurality of thermal signals (iii) an estimated amount of viral particles concentration shed by a plurality of infected subjects at one or more of equally spaced cells in a preoccupied open plan space of the building, and (iv) a susceptible probability of an uninfected subject infected at predefined exposure time, and (v) a one or more neighboring cells adjoining the infected cells; and estimating, via the one or more hardware processors, using a joint actuator control technique, energy consumed by an HVAC (heating, ventilation and air conditioning) controller for the building based on the determined maximum allowable occupant count, wherein the HVAC controller comprises a plurality of actuators in the open plan space of the building based on (i) the HVAC controller energy computed using a chiller energy and an actuator supply fan energy, (ii) a predefined temperature range, (iii) a cooling load of each actuator computed using a mass flow rate of the corresponding actuators, an enthalpy of actuator supply, and return air, and (iv) maximum average cell temperature range, and minimizing the HVAC controller energy consumption after considering the thermal and bio-safety properties if the actual occupant count required is less than an optimal maximum allowable occupant count.