## 11.1 Overview

This chapter summarizes the building performance approach to be used for compliance. It includes a discussion of the alternative calculation methods, the procedures involved in determining the energy budgets of the Standard Design and Proposed Design Building, and how to plan check performance compliance documentation. The basic procedure is to show that the Time Dependent Valuation (TDV) energy of the proposed design is less than or equal to the TDV energy of the standard design. The standard design is a building with the same geometry as the proposed design but the envelope, lighting and mechanical features are defined by the mandatory and prescriptive requirements of the Building Energy Efficiency Standards (Energy Standards). The standard design features are defined in detail within the Nonresidential Alternative Calculation Method Reference Manual.

The performance method is the most detailed and flexible compliance path. The energy performance of a proposed building can be calculated according to actual building geometry and site placement. Credit for certain energy features, such as a high efficiency mechanical system, cannot be taken in the prescriptive approach, but can be evaluated with an approved compliance software program utilizing the performance approach.