There has been some confusion around this issue with LEED users sharing feedback that LEED reviewers are requiring a high level of controllability with both dual switching and dimming for every multi-occupant space. The LEED Reference Guide simply states that you must “provide lighting system controls for all shared multi-occupant spaces to enable adjustments that meet group needs and preferences.”
No. The only option in any of these cases will be the simulation or the measurement methods.
No, the compliant square footage would be the worst-case scenario between the two times. For example, a 900 ft2 space located on the western side of a building is 100% compliant at 9 a.m. but only 50% compliant at 3 p.m. The compliant square footage in this case is 450 ft2.
You must submit a spreadsheet which contains all the information required on the calculator, and submitting the LEED Online calculator is recommended, but some teams have preferred to create their own, and have had them accepted.
On LEED Online, in the credit, under credit resources.
LEED does not prescribe the date or time, but it is recommended that they be taken close to noon under clear sky conditions, and, if possible, on or near one of the two equinoxes.
The LEED v4 Reference Guide has additional guidance on how to classify spaces and how to determine which spaces are included for each IEQ credit. For this credit, daylight modeling or measurements must be conducted in all regularly-occupied spaces, which is any place where people spend an hour or more per day conducting typical activities. Regularly-occupied spaces that are only used for video conferencing, like teleconfencing rooms or dedicated video conference rooms, can be excluded from the credit. Auditoriums must be included but have a lower acceptable illuminance level.
GBCI is denying credit compliance on this basis. It does not offer a path for making up for this issue. The LEED Reference Guide states: "Not all outside air is equal. Depending upon geography and season, it can be very cold or damp. Because of this, prudent limits have been set to ensure no harm comes to the building and potentially to the occupants." While this is not stated explicitly in the reference guide, the logic is that this air potentially damages the building in a way that cannot be mitigated by additional flushout time or volume.
According to USGBC, the addendum was intended to give project teams more flexibility in testing locations. The 1/25,000 SF testing rate is still a good rule of thumb and is acceptable. USGBC is trusting that the project's industrial hygienist will have the best understanding of how to accurately test the spaces in the project. Select spaces to be tested so that each occupiable space type is adequately represented. Additional guidance can be found in the pilot prerequisite for performance-based IAQ.