What lighting can be excluded from the calculations if used for a limited time in the evening?

The correct choice focuses on floodlighting of school sports grounds, which can be excluded from calculations if used for a limited time in the evening. This is because floodlights are commonly utilized during specific events, like sports games or practices, rather than being on for extended or continuous periods. The limited operational hours mean they do not contribute significantly to overall energy usage calculations related to building operations.

This approach aligns with sustainable design principles by recognizing that certain lighting, even if it consumes energy, is not part of the normal building lighting load if used intermittently. This consideration helps in incentivizing designs that prioritize energy efficiency while accommodating necessary lighting for activities that occur outside business hours.

In contrast, garden lights, decorative lighting, and street lighting typically serve more continuous or decorative purposes and are generally counted in energy calculations as they contribute to the overall occupancy and functionality of spaces outside of specific event times. Thus, it is important to distinguish the irregular use of floodlighting from other lighting types to ensure accurate energy assessments and compliance with the Pearl Building Rating System's sustainability goals.