602.1 The Energy Use Budget shall be calculated for the appropriate Prototype or Reference Building in accordance with the procedures prescribed in subsection 502 with the following exceptions: The Energy Use Budget shall be stated in units of Btu/ft 2/yr and the simulation tool shall segregate the calculated energy consumption by fuel type producing an Energy Use Budget for each fuel (the fuel selections having been made by a life cycle cost analysis in determining the proposed design).

602.2 The Energy Use Budget is calculated similarly for the Reference or Prototype Building using equation 602.2.

Where EUB1, EUB2, EUBi are the calculated annual energy targets for each fuel used in the Reference or Prototype building and f1, f2, . . . fi are the energy conversion factors given in Table 602.2, Fuel Conversion Factors for Computing Design Annual Energy Uses. In lieu of case by case calculation of the Energy Use Budget, the designer may construct Energy Use Budget tables for the combinations of energy source(s) that may be considered in a set of project designs, such as electric heating, electric service water, and gas cooling or oil heating, gas service water and electric cooling. The values in such optional Energy Use Budget tables shall be equal to or less than the corresponding Energy Use Budgets calculated on a case by case basis according to this section. Energy Use Budget tables shall be constructed to correspond to the climatic regions and building types in accordance with provisions for Prototype or Reference Building models in subpart E of this part.