This paper describes a comparison of the BLAST program predictions of the energy consumptions of two office buildings with the energy consumptions indicated by the utility bills. In each case the weather data used in the BLAST simulation was for the year for which the utility bills were available.

The process of modeling these two buildings and the problems of producing adequate predictions of building energy consumption are reported. This work was not an attempt to verify the BLAST program. Verification of a computer program must be carried out in detail, not by overall comparisons with specific buildings. This work was oriented towards an accurate description of a build­ing as a first step in an energy conservation study and it is from that perspective that the agreements and disagreements between the measured and predicted data will be discussed.