This credit encourages project teams to reduce the amount of mercury used in building lighting. When building management controls all lamp purchases, the credit is readily achievable, while multi-tenant buildings with decentralized purchasing will find it more challenging.

Remember that the mercury content of each individual lamp does not need to meet the credit threshold of 70 picograms per lumen hour. Your team needs to meet this target on average for all lamps purchased during the performance period. This provides teams with some flexibility in selecting lamps.

Teams should use the USGBC calculator to track and document lamp purchases. Updating the calculator as lamps are ordered can help you confirm that, on average, your purchases during the performance period are meeting the 70 picograms per lumen hour target.

What’s New in LEED v4

• The mercury limit has been reduced from 90 picograms per lumen hour to 70.
• The NEMA exemption for compact fluorescent lamps (CFLs) has been removed.
• Based on the current USGBC calculator and credit form, teams no longer need to provide a lamp inventory (e.g. the “lamp purchasing plan”). Only documentation of the lamp purchases made during the performance period needs to be provided.

Readiness Review Questions

• In multi-tenant facilities, does the project team control lamp purchasing throughout the building? If not, are any tenants likely to be unwilling or unable to share lamp purchasing data? 

• Are lamp vendors or manufacturer representatives available to help identify low-mercury lamp options? 

• Who is responsible for placing purchase orders for lamps? Can they be responsible for tracking lamp purchases over the performance period?