The space-by-space method might be better if you have lots of display or decorative lighting. It allows you to take credit for lighting power optimization for each space. In general, the LPD requirements are less stringent than the building area method, a

The space-by-space method might be better if you have lots of display or decorative lighting. It allows you to take credit for lighting power optimization for each space. In general, the LPD requirements are less stringent than the building area method, and increases to lighting power allowances are allowed for decorative appearance lighting and for highlighting merchandise. However, it’s more work to document the space-by-space method.