This Bird's Eye View text is from USGBC's MPR Supplemental Guidance Revision #2. See the Credit Language tab for the MPR requirements.
INTENT
Many prerequisites and credits throughout the LEED rating systems evaluate the impact of the LEED project building on the building users, particularly those prerequisites and credits in the IEQ credit category. It is therefore appropriate and necessary to require that a minimum number of people benefit from the strategies implemented in a LEED project building in order to earn any credits.
In LEED-EB: O&M, compliance with many prerequisites and credits is evaluated based on actual usage patterns. Therefore, it is necessary to require that typical usage of the LEED project building is underway during the performance periods, so that accurate measurements can be taken.
SPECIFIC ALLOWED EXCEPTIONS
MINIMUM OCCUPANCY RATE APPLICABLE TO LEED-EB: O&M ONLY
Unexpected and temporary decline in occupancy
If occupancy unexpectedly and temporarily falls below the required threshold within the period of time subject to this MPR1, but still meets the requirement using a weighted average (as described below), the project team must submit a description of the situation as well as the measures they have taken to keep the reduced occupancy numbers from affecting the results for each prerequisite and credit that deals with occupancy. Explanations specific to a prerequisite or credit should be given in the optional section for that prerequisite or credit, and general descriptions should be given in PIf1 in LEED Online v3.
Any building that experiences occupancy of less than 100% during a performance period should refer to the LEED-EB: O&M Reduced Occupancy Guidance located on the LEED-EB: O&M rating system page at usgbc.org when completing submittal requirements.
Determining compliance with fluctuating occupancy rates
All buildings, except for hotels, are considered to be in compliance with this MPR if more than 50% of its floor area is fully occupied (e.g., in a state of typical physical occupancy). This should be time-averaged over the performance period for all prerequisites and attempted credits, including the 12 months leading up to the initial submittal of application for review. The threshold for hotels is 55%.
EXAMPLE
A hotel has 100 equally sized rooms and no common space aside from a small lobby. Since the hotel was built, sixty of the rooms have been full as an annual average, taking into account all seasons. Therefore, it is considered to be in compliance with this MPR because sixty percent (60/100 = 60%) exceeds the minimum threshold of 55%.
EXAMPLE
There is a school with nine equally sized classrooms and circulation space equal to the square footage of one classroom. Four of the classrooms are not being used, but the other five are being fully used. Therefore, occupancy for the entire building is at sixty percent (5+1/10 = 60%). If attendance in three of the classrooms drops to 50% each, then occupancy for the entire building drops to 45%, and compliance with this MPR is in question.
The following formula may be used for more precise calculations in determining compliance:
[ (number of days at x% capacity * x%) + (number of days at y% capacity * y%) + ( ... ) ] / total days in operation
EXAMPLE
An office building with ten equally sized floors submits for preliminary review on January 1; exactly a year after its earliest performance period began. It is open 260 days a year. The building operated at full capacity for the first 150 work days of that year. Unexpectedly, six floors become vacant (occupancy drops to 40%) for 50 days. Then, those six floors become occupied again, each operating at half its capacity for the last 60 days (occupancy for the entire building rises to 60%).
[ (150*1) + (50*.4) + (60*.6) ] / 260 = 79%
Because offices are required to be at 50% capacity at a minimum, this building is in compliance with this MPR.
Minimum Occupancy Rate Threshold Change
In fall 2009, the minimum occupancy rate threshold for LEED-EB: O&M changed from 75% to 55% and 50%, as detailed above. This change was a result of current marketplace conditions, and was approved by the LSC. This threshold is not expected to change in the foreseeable future. If and when it does change, the revision will only apply to projects registered after the date the change is posted.
ADDITIONAL INFORMATION AND CLARIFICATIONS
FULL TIME EQUIVALENT OCCUPANCY APPLICABLE TO ALL RATING SYSTEMS
Calculation method for determining annual FTE in design and construction projects
Although each building varies in regular occupancy, the purpose of setting the baseline annual FTE is to ensure sufficient occupancy to warrant awarding points in the IEQ credit category.
Annual FTE is based on the average 40 hour work week, assuming 48 total work weeks in the year. Based on this assumption, one annual FTE is defined as one person spending eight hours a day for 240 days in the building, or 1920 hours annually. The calculation can be done by average FTE occupants per day, week, or month:
By day, must be greater than or equal to 240: (total occupant hours in an average day/8) x number of occupied days
By week, must be greater than or equal to 48: (total occupant hours in an average week/40) x number of occupied weeks
By month, must be greater than or equal to 12: (total occupant hours in an average month/160) x number of occupied months
EXAMPLE
A religious worship facility has an hour-long service once a week for a year and an average of thirty people attends each service. The building stands empty the remainder of the time. The annual FTE calculation for this building is:
(30 total occupant hours in an average day / 8) x 52 occupied days = 195
(40 total occupant hours in an average day / 8) x 52 occupied days = 260
Therefore, the combined occupant (employee, staff, student, visitor) hours result in the equivalent of one person spending 195 eight hour days in the facility. IEQ credits may not be pursued. However, if it gains 10 new members, this MPR would be satisfied:
Only occupant hours that the building expects to accommodate under normal building operations shall be included in annual FTE calculations. The project team must make a reasonable projected estimate when determining FTE.
For projects using rating systems other than LEED-EB: O&M, the projected date of full occupancy is irrelevant to this MPR.
MINIMUM OCCUPANCY RATE APPLICABLE TO LEED-EB: O&M ONLY
Space types subject to this MPR
Gross floor area that is designed to be regularly occupied should be the focus when determining compliance with this MPR.
Any common space such as a lobby or bathroom that receives regular use, as well as any space that does not typically have occupants (such as closets or mechanical rooms), counts toward compliance with this MPR. Common space that is not receiving any use (e.g. a bathroom on a floor completely devoid of occupants) does not count toward compliance.
Determining typical physical occupancy
The definition of typical physical occupancy is ‘The state in which normal building operations are underway and the building is in use by the average number of FTE occupants for which it was designed.’
To determine the average number of FTE occupants the building was designed for, project teams must assess buildings on a case by case basis, using reasonable judgment. Design intentions, floor area capacity, and building system capacity must all be considered. Atypical or indeterminate cases must be described in the PIf1 in LEED Online v3.
Space is considered occupied based on actual usage, NOT leasing. Leased space is only considered occupied if it is physically occupied.
1 As stated in the MPR language, the period of time subject to this MPR includes at least the 12 continuous months immediately preceding the first submission for a review and all performance periods.
