9A-i 

APPENDIX 9A. LIGHTING CONTROLS 

TABLE OF CONTENTS

9A.1 LIGHTING CONTROLS ....................................................................................... 9A-1

9A.1.1 Background ............................................................................................................. 9A-1

9A.1.2 Approach ................................................................................................................. 9A-1

9A.1.2.1 The Impact of State Building Codes on Controls Penetration .............. 9A-1

9A.1.2.2 The Impact of Other Factors on Controls Penetration .......................... 9A-3

9A.1.3 Results and Conclusions ......................................................................................... 9A-3

LIST OF FIGURES

Figure 9A.1.1 U.S. Total Annual Commercial Lighting Capacity and the Capacity 

Projected to be Operating under Lighting Controls .................................... 9A-4
9A-1 

9A.1 LIGHTING CONTROLS

9A.1.1 Background 

Lighting controls include a range of technologies to turn lights off or down when they are

not needed or wanted. Of interest to this rulemaking are control technologies that go beyond 

manual on-off switching, which is almost universally included in lighting. These include manual 

dimmers, automatic timers, and sensor-based controls. Timers can be used to automatically 

adjust lighting based on occupancy schedules and daylight hours. More advanced sensor-based 

controls adjust light output based on signals received from the sensors. Occupancy sensors—

often referred to as motion sensors for outdoor applications and vacancy sensors for indoor 

applications—include infrared, ultrasonic, and, to a far lesser extent, microwave sensors. 

Photosensors are used to adjust light output to account for background light levels, typically 

from daylight. 

 The purpose of this appendix is to describe the assumptions and analysis the U.S. 

Department of Energy (DOE) used to project changes in the penetration of lighting controls over 

the analysis period of this rulemaking. DOE incorporates lighting controls in the analysis, 

because they can indirectly affect lamp lifetimes and, therefore, shipments (chapter 9); controls 

also directly affect lamp energy use and, therefore, the national impact analysis (chapter 10). 

There are large, inherent uncertainties in the extent to which the penetration of specific controls 

technologies will change over time. The next section describes the approach DOE took to 

estimate the penetration of lighting controls technologies in the building stock for the shipments 

and NIA analysis for this rulemaking. 

9A.1.2 Approach

DOE considered the impact of state building codes and other factors in estimating the 

adoption of lighting controls over the analysis period, as described in the following sections. 

9A.1.2.1 The Impact of State Building Codes on Controls Penetration 

Federal model energy codes drive the adoption and revision of state building codes. DOE 

adopts different model codes for commercial and residential buildings. ASHRAE Standard 90.1 

is the model energy code for commercial and multi-family high-rise residential buildings. The 

International Energy Conservation Code (IECC) is the model energy code for low-rise residential 

buildings. Both include provisions on lighting and are updated periodically. The Energy 

Conservation and Production Act (ECPA), as amended, requires that DOE, within one year of 

revision of either document, issue a determination as to whether the revised edition will improve 

energy efficiency compared to previous editions.1

 If DOE finds that the newest version of 

ASHRAE 90.1 is more energy efficient than the previous version, states are required by the 

Energy Policy Act of 1992 (EPACT 1992) to certify that their building energy codes or standards 

meet or exceed the requirements of the new standard within two years. If the analysis shows that 

the revised IECC is more energy efficient than the previous edition, EPACT 1992 requires to 

certify that they have reviewed their residential building energy codes regarding energy 
9A-2 

efficiency and made a decision as to whether it is appropriate for that state to revise its 

residential building code to meet or exceed the revised code. 2 

Therefore, state compliance with the model codes is compulsory for commercial 

buildings, but not for residential buildings. DOE therefore treated the two sectors different in this 

preliminary analysis. For the residential sector, DOE assumed that the use of lighting controls 

remains constant at today’s level. DOE seeks input from stakeholders on the validity of this 

assumption. 

To project the future penetration of commercial lighting controls, DOE assumed that state 

building code requirements remain as they are today, with controls being installed as required for 

new construction and renovation. The current model energy code for commercial buildings, 

ASHRAE 90.1-2007, section 9.4.1.1, mandates that almost all interior lighting be controlled 

either by a timer, an occupancy sensor, or a signal from a separate system. Exceptions are made

for buildings that are less than 5,000 square feet in floor area and for health and safety; hospital 

operating rooms and spaces that specifically require 24-hour lighting. In the current building 

stock, the square footage covered by these exceptions totals 9% of commercial floor space. Most 

of that is exempted because the floor area is less than 5,000 square feet. However, DOE has 

determined that ASHRAE 90.1-2010 will yield significant additional savings, so it will become 

the new model code. The 2010 code eliminates the exception for commercial buildings less than 

5,000 square feet, with the result that an estimated 98% of total commercial floor space would be 

required to include lighting controls—essentially all viable floor area. DOE does not model the 

adoption of the 2010 code in this rulemaking because it is uncertain if and when states will adopt 

the code. 

In addition to the mandatory general lighting provisions of section 9.4.1.1 described 

previously, ASHRAE 90.1-2007 includes additional requirements for lighting controls in some 

smaller spaces, such as individual offices, which may be superimposed on controls required 

under the general provisions. DOE did not attempt to account for the effect of multiple layers of 

controls or improvements in control technologies that may take place over time. This appendix 

calculates only the lighting capacity (in teralumens) covered by controls. Given the lack of data 

on whether multiple levels of controls would be adopted and which controls will be adopted in 

which areas, the energy use calculations in chapter 10 assume that controls yield a fixed 30% 

energy savings if controls are required for the floor area.

3

Compliance rates are the largest source of uncertainty in the analysis. Given that all of the 

most populous states are currently compliant with the federal requirement to adopt the model 

code or better, future changes in the level of state compliance should do little to change the 

results of the energy analysis. The level of builders’ compliance with state codes is less clear. 

This preliminary analysis assumes a 75 percent overall compliance rate, and DOE is considering 

incorporating an uncertainty analysis on compliance rates into it analysis in the NOPR phase of 

this rulemaking. DOE is seeking data on current compliance rates. 

 Using the assumptions described above, DOE estimated the national commercial lighting

capacity (in teralumens) covered by lighting controls for each year of the analysis, based on the 

floor space projected to be operating under lighting controls, using a computational model 
9A-3 

developed for by Sturges (2012).4 The model estimates the commercial floor area incorporating 

controls, accounting for the current variation in standards adopted by the states, the relevant floor 

area in each state, the breakdown of floor area by application, and the code requirements for each

floor area application. Because the analysis period in Sturges’ study extended only until 2030, 

for this rulemaking DOE extrapolated Sturges’ projection to the end of the analysis period 

(2046). The results of the analysis are described in section 9A.1.3. 

9A.1.2.2 The Impact of Other Factors on Controls Penetration 

 In addition to lighting controls installed as a result of state building codes, some fraction 

of building owners install controls for other reasons. For the commercial sector, DOE computed 

the current lighting capacity installed for other reasons from the difference between the current 

total lighting capacity under controls and the lighting capacity under controls as a result of 

building codes, based on Sturges’ model. DOE’s 2010 Lighting Market Characterization (LMC) 

estimates that 30% of commercial lighting was governed by lighting controls in 2010.5 The LMC 

estimated that 30% of commercial lighting is governed by lighting controls. The building codes 

analysis estimated that state codes would have resulted in only 12% of floorspace having 

implemented lighting controls at the beginning of the analysis period. Assuming that floorspace 

fractions equate approximately to lighting fractions, an estimated 18% of commercial lighting is 

assumed to be using lighting controls for other reasons. DOE held that fraction fixed throughout 

the analysis period. 

9A.1.3 Results and Conclusions

Figure 9A.1.1 shows DOE’s projection of the teralumen hours of capacity expected to be 

operating under controls as a result of building codes, and for other reasons. Total lumen 

capacity is also included in the plot to facilitate comparison. As shown, by the end of the analysis 

period approximately 75% of commercial floor space is expected to be operating under lighting 

controls, assuming that today’s building codes remain frozen in place and a 75 percent 

compliance rate. If ASHRAE 90.1-2010 is adopted by the states, there will be some increase in 

lumen capacity covered by controls, because the lighting controls exception for small buildings 

will be eliminated. The magnitude of that increase will depend on which states adopt the 

standard and when. However, a larger uncertainty appears to be the rate at which builders 

comply with state code requirements. Currently, DOE is assuming a 75% compliance rate. DOE 

is considering including an uncertainty analysis in the NOPR that assumes 50% and 100% 

compliance rates. DOE seeks feedback and data to better inform its analysis.
9A-4 

Figure 9A.1.1 U.S. Total Annual Commercial Lighting Capacity and the 

Capacity Projected to be Operating under Lighting Controls 

REFERENCES

1 http://www.energycodes.gov/regulations

2 http://www.energycodes.gov/regulations/determinations

3

 Williams, A., B. Atkinson, K. Garbesi, E. Page, and F. Rubinstein (2012). Lighting controls in 

commercial buildings. Leukos 8(3): 161-180. http://www.ies.org/leukos/samples/1_Jan12.pdf

4 Sturges, A, "Modeling the Market Penetration of Advanced Lighting Controls in the U.S 

Commercial Sector" (master's thesis, Duke University, Nicholas School of the Environment, 

2012). Available online at http://dukespace.lib.duke.edu/dspace/handle/10161/5278

5 U.S. Department of Energy- Energy Efficiency & Renewable Energy Building Technologies 

Program. 2010 U.S. Lighting Market Characterization. January 2012. Washington, D.C. 

<http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/2010-lmc-final-jan-2012.pdf>