3.6.8

Typical Office Building (1)

Large

Small

(>= 25,000 SF)

(<25,000 SF)

Stock Floor Area (billion SF)

8.22

4.29

Floor-Area Weighted Averages

Building Area (thousand SF)

90 - 137

5.5 - 6.6

Floors

39,240

39,084

Shell

Percent Glass

40 - 50

15 - 20

Window R-Value

1.39 - 1.71

1.34 - 1.99

Window Shading Coefficient

0.69 - 0.8

0.71 - 0.82

Wall R-Value

2.5 - 6.0

3.9 - 6.3

Roof R-Value

9.1 - 12.6

10.5 - 13.3

Wall Material

masonry

masonry

Roof Material

built-up

built-up

Occupancy

Average Occupancy (SF/person)

390 - 460

420 - 470

Weekday Hours (hrs/day)

12

11

Weekend Hours (hrs/day)

5

4

Equipment

Average Power Density (W/SF)

1

1

Full Lighting Hours (hrs/year)

3,580

3,360

Lighting

Average Power Density (W/SF)

1.3 - 1.8

1.7 - 2.2

Full Lighting Hours (hrs/year)

4,190

3,340

System and Plant

System and Distribution Type

Constant Volume w/ Reheat

Packaged Single-Zone

VAV w/ Economizer

Packaged Single-Zone w/ Economizer

Heating Plant

Gas Boiler

Gas Furnace

Cooling Plant

Hermetic Centrifugal Chiller

Direct Expansion

Service Hot Water

Gas Boiler

Gas Water Heater

Note(s):

1) The prototypes are synthetic buildings compiled from statistical data from building surveys or conclusions from previous studies. The physical characteristics, system characteristics, and usage patterns are based upon various surveys, studies, engineering estimates, or engineering judgment.