A system and method to control environmental parameters of pre-defined zones within an environment using an electronic controller are disclosed. The system includes a non-proprietary electronic controller which enables a weighting value to be assigned to each zone within the environment. The electronic controller also detects any zone service calls from sensor devices associated with each of the zones and determines a cumulative weighting value in response to the detected zone service calls. The electronic controller selects an equipment staging combination from at least two possible equipment staging combinations in response to thermal capacity, and an air handler stage is selected in response to at least the cumulative zone weighting value.