A new "landscape budget method" has been added for this credit through the November 2010 LEED addenda. This method could be very useful for teams that are close to meeting the buffer zone requirement, but having some difficulty. If a project is meeting 3 of 4 requirements but can't meet the fourth, it can do the following calculation to demonstrate compliance. As a baseline calculation, calculate the area of site disturbance that would take place if you met all four of the requirements exactly.
Safety concerns are not typically a valid excuse for higher exterior lighting allowances. Despite a perception of better safety with brighter lighting, floodlights can often create areas of deep shadow, and the high contrast can be difficult for the human eye to navigate. Use good design, downlights, and work with the owner to address any concerns.
LEED project boundary considerations: The master plan can encompass future development which is outside the current LEED boundary, but isn’t required to—the decision is up to the project team. If the project team chooses to use their LEED boundary the site must have future development plans. If the boundary is made larger it must be clearly defined and the project must be able to achieve credits within the larger zone that it is already meeting for the smaller LEED project boundary.
Different building types call for different calculations under this credit—make sure you’re using the proper variables for your building type. Residential project teams should also keep in mind that bike storage facilities must be covered—which is not part of the credit requirements for other building types—and that this will impact building design.
Set daylighting goals at the initial goal-setting workshop and incorporate them into the Owners Project Requirements document required for EAc1: Fundamental Commissioning.
When programming, identify occupant lighting needs that could be met instead with daylight. The Illuminating Engineering Society of North America (IES) has prescribed foot-candle levels for project types, occupant types, and tasks.
Large areas of glazing may cause unwanted heat gain and compromise energy efficiency. However, daylighting may require less glazing than you think—about 40% window-to-wall ratio may be more than you need. Glazing closer to the ceiling will have a greater daylight benefit than glazing near the floor—anything below 30 inches is considered to have no daylight benefit.
