The credit requires a photometric study on site lighting that may add minor consultant costs but will add value by optimizing the design.

Local or regional laws that regulate lighting levels typically do not require minimum input power in watts. Going beyond these local requirements by selecting energy-efficient fixtures can help your project meet codes for comfort and safety goals without compromising energy efficiency.

Core and Shell projects must comply with LEED requirements for all the exterior and façade lighting within the project scope and construction budget. Interior lights fitted by the owner must also comply with LEED’s control requirements. Fixtures not installed within the scope of the LEED project are exempt from credit requirements.

Discuss fixture and lamp options with the landscape designer, civil engineer and other project team members, focusing on both reducing overall lighting power density, and on avoiding light trespass. Avoiding light fixtures that shine up into the sky is the easiest way to reduce light pollution and make better use of lighting. This can be done by eliminating exterior lighting entirely or by selecting “cut-off fixtures” with opaque covers that direct light downward.

Identify local or regional lighting laws or required lighting levels for rights-of-way that may apply to the project site. These regulations may help teams identify areas to focus on when dealing with lighting trespass in the design.

Campus projects can choose whether to comply with the requirements for the building site boundary or to meet the light trespass requirements for the campus as a whole. For a project on a campus, choosing to meet the light trespass requirements at the building level can be very difficult.

Projects with a zero lot line may choose to use the curb as the LEED boundary for the purposes of documenting light trespass only, while using the site boundary for other credits. This is one of the few exceptions to the rule that the LEED boundary and corresponding site area be consistent across multiple credits. Sites that abut public rights of way may similarly use the curb to establish the site boundary for the purposes of LEED documentation.

Finalize the LEED project boundary in coordination with other LEED credits. The responsible party and the project team should identify the lighting fixtures close to the boundary that will be part of the lighting trespass analysis.

Identify the urban lighting zone as defined by IESNA RP-33, based on the population density of the neighborhood, in order to establish lighting requirements.

Projects that demand brightly lit facades and entrances, such as casinos, hotels, theatres and commercial complexes, may have a hard time reconciling these desires with the requirements of this credit. Deliberate lighting design can forge a compromise between the desire to emphasize the building facades and the need to eliminate light pollution in order to meet the credit requirements.