ASHRAE’s exterior lighting density table (table 9.4.5) lists exterior spaces under two categories. Tradable spaces are those where the average LPD of all those spaces are within the total LPD limits. For example, in parking lots and drives, lighting

ASHRAE’s exterior lighting density table (table 9.4.5) lists exterior spaces under two categories. Tradable spaces are those where the average LPD of all those spaces are within the total LPD limits. For example, in parking lots and drives, lighting needs to be a maximum of 0.15 Watts/ ft2. The project may decide to increase driveway lighting to 0.2 W/sf as long as the parking lots compensate with a LPD of 0.1 W/ft2 so that the average of the two is 0.15 W/ft2. For non-tradable surfaces, such as bank ATMs, each space must individually comply with the ASHRAE requirements. Identify whether exterior spaces are tradable in order to provide flexibility.