How is the exterior lighting power allowance (ELPA) determined?

The determination of the exterior lighting power allowance (ELPA) is primarily done through site measurements and the use of a measurement table. This approach ensures that the assessment takes into account the specific characteristics of the site, including its size and intended use, which are critical for creating an appropriate and effective lighting design.

By utilizing a measurement table, landscape architects can reference predefined values that correspond to various site types and conditions. This method provides a standardized way to assess the allowable wattage based on the site’s features, ensuring that the lighting design complies with regulations while also enhancing safety, functionality, and aesthetics.

The accuracy of ELPA derived from site measurements helps mitigate issues such as light pollution and energy overuse, making it a key factor in sustainable landscape architecture. Thus, the correct method emphasizes the importance of an evidence-based approach tailored to the specific site, rather than solely relying on wattage totals, light pollution assessments, or local ordinances.