Prescriptive vs Performance Compliance

The Energy Code offers two compliance approaches, and choosing well can be the difference between a design that gets approved and one that has to change.

Prescriptive

Essentially a recipe. Meet each listed requirement — insulation levels, window performance, equipment efficiencies — and you comply. It is simple and predictable, but rigid: miss one item and you do not comply, regardless of how the building performs overall.

Performance

Uses CEC-approved compliance software to model your proposed design against a standard design. If your building's modelled energy use meets the budget, it complies — even if individual components fall short of the prescriptive values. This allows trade-offs: more glazing offset by better insulation or more efficient equipment.

Which is used more

Performance, because of that flexibility. Real designs rarely match a prescriptive package exactly.

Zone-specific budgets

The energy budget a performance model is measured against varies by climate zone and building type. This is a core reason a report cannot be reused across cities.