A system and method generates test vectors and a corresponding test program to manipulate terminal units in a building system so pressure and flow measurements correspond to independent modeling equations. The pressure and flow responses of the building system to the test program manipulation may be used to compute loss coefficients for the modeling equations. The modeling equations may then be updated with the computed loss coefficients so a building simulation may be performed. The simulated static pressure response of the modeling equations may be compared to measured static pressures to evaluate the sufficiency of the modeling equations.