Energy and Design PCs Computers can help in lots of ways, but don't spend $500 on energy analysis to shave a few dollars off the heating bill. by Drew Gillett Despite 15 years of effort by governments, professional associations, engineers, and researchers, there is still no foolproof method to calculate the energy requirements of any given building. Why? Buildings are complex systems that interact in complex ways with their occupants, energy systems, and climates. Specifying all this input data-if you can find it-for any method of calculation, takes a great deal of time, more than can usually be justified on a single project. Furthermore, more, few buildings are built precisely as designed. Consequently, predictions are often off by more than 50 percent of the building's actual
