1. A computer implemented method for determining a heating, ventilation, and air conditioning (HVAC) model for a building, comprising: receiving, by a processor, a description of the building from a user, wherein the description of the building includes physical connections between components of an HVAC system of the building; receiving, by the processor, an HVAC meta-model, wherein the HVAC meta-model is independent of the building; determining, by the processor, a predictive HVAC model for the building based on the description of the building and the HVAC meta-model; and using, by the processor, the predictive HVAC model for the building to control the HVAC system of the building based on predicted operating conditions of the components of the HVAC system, wherein the predicted operating conditions include a predicted water temperature and a predicted water velocity of a boiler of the HVAC system.