Page 140 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

120 Cha pte r T h ree

The FTE is then determined by using the following set of equations from Chap. 2:
j
FTE = (worker i h)/8 h where 0 < FTE ≤ 1 (2.4.1)
j,i j,i
FTE = ∑ FTE for all employees in shift j (2.4.2)
j j,i
Then the full-time employee equivalents need to be subdivided by gender. For each
shift the numbers for male and female employees may not be equal. Let FTEM and
j
FTEF be the male full-time employee equivalent and the female full-time employee
j
equivalent for shift j, respectively. To be consistent throughout the LEED submittal, the
following equality must hold for all shifts j:
FTE = FTEM + FTEF for all shifts j (3.2.1)
j j j
In SS credit 4.2, the transient occupancies are estimated as average transient
occupancies at any time over a shift, not as the total number of transient occupants who
may go in or out of the building during the shift. This is done to estimate the peak
number of bicycle rack spaces needed at any time. For example, if the building is a
college building with faculty and staff offices and student classrooms, then in SSc4.2 the
FTE portion of the calculations is based on the staff and faculty in the building during
j
the typical workday, and the transient population is the average occupancy of the
classrooms and study areas over this typical 8-h class time, not the total number of
students who come in and out. The students may be in other campus buildings for
other classes throughout the day. However, in WE credit 3 the LEED-NC 2.2 and 2009
Reference Guides base transient uses on the total number of transients, not the average
over the shifts. To be consistent with these other water credits, let us define TOWM and
TOWF to be the estimated total number of male and female transients, respectively,
during a day. (TOW would be the summation of TOWM and TOWF.)
As mentioned previously, LEED-NC 2.2 and 2009 recommend that the typical daily
fixture usage rates for water closets and urinals be separately analyzed for the different
genders, building usages, and occupancies. Let WCUM and WCUF be the male water
i i
closet and female water closet usage rates, respectively, for various types of buildings
or occupancies. Let UUM and UUF be the male and female urinal usage rates,
i i
respectively, for various building types and occupancies. Table 3.2.1 gives some typical
default values for these daily fixture usage rates. It is important to also analyze the
building usage on an annual basis. Let ND and ND be the number of days in a
FTE TOW
year that each type of occupancy (FTE or TOW) uses the building. ND is usually 260
FTE
days for office buildings and 365 days for residential or retail. For college buildings,
ND may be 260 for staff and faculty, but ND may be much less for student
FTE TOW
occupancies. Summing the fixture usage rates times the occupancies over the various
shifts as applicable for the entire year gives the total number of times water closets and
urinals are typically used in a year (TWCU and TUU, respectively):
TWCU = ND [∑ (FTEM × WCUM ) + ∑ (FTEF × WCUF )]
FTE j i j i
+ ND [(TOWM × WCUM ) + (TOWF × WCUF )]
TOW i i
over all shifts j and for each type of use i (3.2.2)
TUU = ND [∑ (FTEM × UUM ) + ∑ (FTEF × UUF )]
FTE j i j i
+ ND [(TOWM × UUM ) + (TOWF × UUF )]
TOW i i
over all shifts j and for each type of use i (3.2.3)