LEED v2009 NC Total Daily Occupancy

Sorry for the delay in replying.
You do need to include an estimated occupancy for all spaces, even if they aren't going to be built out for awhile. You can calculate the occupancy for shell spaces using the Core and Shell Appendix 1 Default Occupancy Counts on page 611 of the BD&C Reference Guide where it lists the gross square feet per occupant for employees and transients.

For retail space, the defaults are 550 sf for employees, and 130 sf for transients. For a 6000 sf retail space then, you'd assume 11 employees and 46 transients. A post-secondary classroom is 2100 sf/ FTE and 150 sf per student. If the reception area is staffed, you can count that person, and for the office use 250 sf per employee.

David, how do you then figure out peak vs average if you are using default numbers? Do you make assumptions on what time of day would have most retail visitors?

I have a similar question to Ed Clark's from Sep 2013. We have retail and restaurant spaces that will be open 7 days a week. There is no specific time or day of the week that will be a "peak" condition with more customers (transients). We included the same number for average as peak, based on the 130 SF per person for retail and 95 SF for restaurant. It seems the only way the average would be less than the peak is if it was closed for one or two days a week, then the yearly average would be less. Can I just explain this in a narrative or am I missing a method that will reveal a higher peak use?

The Daily Average is almost always higher than the Peak value so that might be a misconception you have (based on your last sentences). As you note, the Peak is only the most people anticipated on-site at a single time whereas the Daily Average is anyone that comes over the course of a typical day. The fact that Daily Average will be greater than Peak is especially true for retail/restaurant spaces as they just simply have a more transient population/turnover. Using a restaurant example where the restaurant seats 100 people, you peak would probably be around 110 (100 diners + maybe a few folks standing around waiting for seats/at bar). Those tables might flip 3 times/night, however, so the Daily Average might be closer to 300 people.

You should be able to calculate a Peak load for the restaurant based on the physical seating capacity. Retail will be slightly harder to estimate but an easy means to come up with a Peak load by dividing their Daily Average value by the number of hours the store is open and then using that value to drive your Peak estimation. For example, if the Daily Average customers is 480 and the store is open for 8 hours/day, your average per hour would be 60/hour. You could assume your Peak value would fall somewhere between 60-120. Setting the final peak might depend on the type of retail business (for example, a coffee shop is generally busier in the morning, and so they might easily hit that higher value regularly as a peak; a clothing store, however, that is open all day might see a more consistent occupancy across the day and so would maybe be closer to the lower value).

Kristina's answer is spot on. Daily Average is the total number of people over the course of an average day.

One key to the PI forms is figuring out where the number for each data field ends up being used. In this example, Peak Building Users (including transients) is used to calculate the number or bike racks, Total FTE (No transients) is used to calculate showers, and the daily average is used for calculating water use in WEp1 (and WEc3).

Note that a key number such as FTE (employees) and Peak Building Users (FTE + Visitors) may be used in a particular credit form such as SSc4.2 or those number values may be needed in a separate credit calculation spreadsheet such as the WEp1 Water Use Reduction calculator.xls. You'll want to manually confirm the occupancy numbers entered in the PIf3 are consistent with what you or your consultants enter in the WE calculator spreadsheet.

Here's a summary for each of the data fields in the PIf2 form what credits it links to:

PIf3: TOTAL GROSS SF/ GROSS FLOOR AREA: PI f2, SSc2 Dev Density, EAp1 Commissioning, EAp2 Min Energy Performance, EAc1 Optimize Energy Performance, EAc2 Onsite Renewables, EAc6 Green Power, MRc1.1 & 1.2 Building Reuse;
PIf3: TOTAL REGULARLY OCCUPIED GROSS AREA: IEQ 8.1, 8.2 Daylight & Views;
PIf3: PRINCIPAL BUILDING ACTIVITY: EAp2 Min Energy Performance, EAc1 Optimize Energy Performance;
PIf3: PEAK BUILDING USERS FTE + TRANSIENTS): SSc4.2 Alt Transit - Bike Storage, Showers;
PIf3: TOTAL FTE (NO TRANSIENTS OR RESIDENTS): SSc4.2 Alt Transit - Bike Storage, Showers, SSc4.3 Alt Transit – Low Emitting Vehicles, SSc4.4 Reduced Parking, EAp2 Min Energy Performance, WEp1 Water Use Reduction;
PIf3: TOTAL RESIDENTS: SSc4.2 Alt Transit - Bike Storage, Showers, WEp1 Water Use Reduction;
PIf3: AVERAGE RETAIL CUSTOMERS: WEp1 Water Use Reduction;
PIf3: AVERAGE TRANSIENTS (STUDENT/ VISITOR): WEp1 Water Use Reduction;
(FYI, this is from the USGBC "Credit Matrix (Jan 2013).xls" spreadsheet.)

Thanks for the response follow up.
To clarify, we have un-leased retail space. The occupancy is based on the GSF area, at 130 SF/occupant.
The retail shops will likely be open 7 days a week. We have no way to anticipate any particular days that will be heavy or light usage. Wouldn't the Peak and Average be the same?
For the restaurant the advice seems to be that if the 2,850 GSF allows 30 occupants (customers), we should assume 3 seatings = 90 plus 10% extra for those waiting for tables, = about 99 people per day. So in the PIf3, the Daily Average would be 99 and the Peak would be 30, assuming open 7 days per week? Then the WEp1 credit is tied to the PIf3 and would be based on the 99 occupants in the restaurant, is that correct?

Sherman,
Your restaurant numbers look almost right. You will need a separate number for employees (FTE) and restaurant customers (Transients) in the water reduction calculator, because they have different patterns of water use (see last paragraph below).
So, using the Default Occupancy table in Appendix 1, for 2850 sf Restaurant the
Employee FTE would be 2850 sf/ 435 (sf per occupant) = 6.5, round up to 7;
Transients would be 2850 sf / 95 (sf per occupant) = 30 Transients.
For 3 seatings you are right, 90 people per day (daily average transients) plus the 7 FTE staff gives us 97 people. In the WEp1 calculator you'll be entering the 7 staff in one cell and the 90 customers in the Transients cell.
Restaurant peak users would be 30 transients + 7 FTE = 37 peak users.
Bike racks are calculated for the total peak user count for the whole buildings.
The # of showers in the bike changing room is based on the staff FTE, as transients & retail customers won't typically be provided showers.

For retail, you didn't mention a total sf, so let's assume 1000 sf of general retail:
Retail Employee FTE = 1000 sf/ 550 sf per occupant = 1.8 so round up to 2 people.
Retail Customers = 1000 sf / 130 sf per occupant = 7.7 so round up to 8 customers.
It's not clear from the table, but I'd assume that number of 8 customers could be the peak retail users,
so total peak users in the retail would be 2 + 8 = 10

How many daily average retail customers? Who knows. A fur coat store in Berkeley, CA might have 1 per day, a downtown convenience store could have a thousand. Just pick a reasonably credible number and move on.... in this example, maybe 8 peak users x 8 hours? 64 average daily users seems like a reasonable assumption. LEED assumes only 20% of those will use a bathroom.

Note that I assumed restaurant customers as Transients, and retail customers as Customers. In the WEp1 Water Reduction calculator you’ll find that Transients are assumed to have more sink and toilet usage than retail customers are, which makes sense for someone using a restaurant. Thus big variations in the retail counts barely moves the needle in overall water use, so I wouldn’t worry about making a rough approximation of total daily users.

As Kristine indicated, average daily users should be more than peak. Running these calcs for a small retail space of 1000 sf makes me think the default occupancy count gives the peak # of customers (8), rather than the total daily average as Kristina may have assumed in her example of 480 customers. She was dividing 480 by 8 hours to get a peak of 60 in one hour, whereas I started with an assumed peak of 8 customers and multiplied by 8 hours to get a daily average total of 64. Either way, daily average is higher than peak.

WEp1 Water Reduction Calculator assumptions (also used for WEc3):
Employees are assumed to use a toilet and hand sink (lavatory) 3 times a day;
(3 toilet flushes/ day for females, 1 toilet and 2 urinal flushes/ day for males)

Transients are assumed to use a toilet and hand sink (lavatory) 0.5 times per day;
(0.5 toilet flushes/ day for females, 0.1 toilet and 0.4 urinal flushes/ day for males)

Retail Customers are assumed to use a toilet and hand sink (lavatory) 0.2 times per day;
(0.2 toilet flushes/ day for females, 0.1 toilet and 0.1 urinal flushes/ day for males)

Hope that helps.

David and Kristina,
Thanks for your explanations and detailed clarifications. We worked out the approach you described and revised the calculations using the offline WEp1 pdf. It seems to work okay with the increased occupant numbers and the use of Customer and Transient adjusted. The final result is just about the same at 30% savings due to our low flow faucets and showers.
A related adjustment we will need to make is in the Tenant Design Guide is to specify the Public Lav faucets for the Retail and Restaurant uses, which are not in our general construction now.
BTW, was the difference between Peak and Daily Average addressed in an earlier Clarification or Interpretation?
Thanks again.

For LEED 2009 PIf3, my understanding for Lodging: Hotel use is that the number of rooms x 1.5/rm x 60% equals the number of residents, and residents are not part of the FTE. Please explain how the resident total is, or is not, part of Table PIf3-3 Total Daily Occupancy for the Peak or Daily average of Transients. Would there only be transients if a full service restaurant or retail for non residents would be in the building? Thank you.

Jennifer: Here is what I have done on past hotel projects: 

1.       Hotel guests are treated as transient occupants for the purposes of this calculation. 

2.       “Peak transient hotel guests” is calculated at 100% occupancy times 1.5 people per room for a hotel times the number of rooms.

3.       “Daily average transient hotel guests” is calculated at 60% occupancy or historical data (per LEED Addendum) times 1.5 people per room for a hotel times the number of rooms.

4.       “Daily average transient visitors” (like people who are at the hotel to attend a meeting or luncheon but are not staying there) are added to peak and daily average transients of the hotel guests as calculated.

Hope this helps.

Hi Summer. Thanks for the feedback. I heard back from USGBC staff who said to keep hotel guests in the Resident count only, and that transients are only on site for meetings, or a hotel full service restaurant if there is one. He explained residents use more water and energy than a Transient (as non residential) would onsite per WEp1. This correlates with "Transient" as USGBC defined as on site for less than 7 hours in some of the interpretations out there. I think the IBC building code use of "transient" for Residential occupancies adds to the confusion. I saw a lot of different approaches on this data even within some CIRs; hopefully eventual USGBC language will make it clear.