general lighting. For guest rooms, the lighting must be turned
off based on occupancy.
Automatic light reduction: ASHRAE/IES 90. 1 2013
requires general lighting in certain applications to be automatically reduced by at least 50 percent when not in use. This
would be achieved using occupancy sensing with a maximum
20-minute time delay. Automatic light reduction enables energy
savings in spaces where the lights are intermittently occupied
but must remain on, such as corridors and stairwells.
Daylight-responsive control: General lighting in daylight
areas or zones in designated spaces must be independently controlled from other general lighting in the same enclosed space.
These controls must be installed if the load is of sufficient size
and sufficient daylight availability is expected.
Daylight areas are designated under toplighting (e.g.,
skylights) and adjacent to sidelighting (e.g., windows). The
dimensions are defined by the applicable energy standard,
90. 1 or the IECC. ASHRAE/IES 90. 1 2013 requires separate
daylight-responsive control in both primary (directly adjacent
to sidelighting) and secondary (directly adjacent to primary
area) daylight areas.
Both standards require the lighting in daylight areas to be
automatically reduced in response to daylight. The control output can be continuous dimming, step dimming or multilevel
switching. The controls must be readily accessible to calibrate.
The standard may apply limits to how the lighting can be controlled to the zones, such as requiring that general lighting in
overlapping toplighted and sidelighted daylight areas be zoned
with the controls used for toplighting ( 90. 1).
Parking garages: ASHRAE/IES 90. 1 2013 requires time-
scheduling control for parking garages. In addition, general
lighting, segmented into 3,600-square-foot control zones, must
be capable of automatic reduction by at least 30 percent during
operating hours using occupancy sensors. Daylight-responsive
control is also mandated with specific requirements.
More robust control system: ASHRAE/IES 90. 1 2013 provides an incentive to install nonmandatory controls as a way
to gain power credits that can be applied to the lighting design
if using the space-by-space method. IECC 2015 requires the
building designer to implement at least one of six additional
energy-efficiency options, two of which are related to lighting.
One option is to reduce maximum lighting power allowances by
at least 10 percent. The other is to install a digital addressable
lighting control system with specific capabilities, features and
Exterior lighting control: Outdoor lighting must be turned
off using an astronomical time switch, light sensor or a combination. Dusk-to-dawn lighting must be turned off based on
daylight and automatically reduce power by at least 30 percent
during certain hours of the night. Facade and landscape lighting
must be turned off at a certain time of night (curfew lighting).
Time switches must be capable of retaining their programming
and time setting for at least 10 hours during a power loss.
Functional testing: Lighting controls must be functionally tested to ensure they operate in accordance with approved
documents. The testing party cannot be directly involved in
the project design or construction. Specific requirements are
mandated for occupancy, time-based and daylight-responsive controls. The testing party must provide the owner with
documentation that verifies the installed controls satisfy the
Documentation: At project conclusion, the owner must be
given certain documents about the lighting and control system
so they can maintain it. This includes drawings and submittal
data, operating and maintenance manuals, a written controls
narrative (sequence of operations), and a recommended schedule for inspecting and recalibrating the controls.
Over the past 15 years, energy codes have steadily become more
detailed and restrictive. This trend has had an extraordinary
impact on demand for lighting controls and product development. Buildings designed to the latest energy codes must turn
off or reduce lighting when it’s not used to a fine level of detail,
resulting in high energy savings, but also making compliance
more complex. As lighting controls become fully expressed in
energy codes, subsequent standard-writing will likely focus on
clarification and making compliance easier.
For more, consult your local energy office, authority having jurisdiction or the energy standards. ASHRAE/IES 90. 1
2013 and IECC 2015 may be purchased at
Lighting Controls Association offers a free online course summarizing control requirements in these codes at its Education
Express system at
DILOUIE, L.C. is a journalist and educator specializing in the lighting
industry. Learn more at
ZINGinc.com and LightNO Wblog.com.
Basic anatomy of ASHRAE/IES 90. 1 2013 and IECC 2015.
> FOCUS DECODING ENERGY CODES
Prescriptive Interior Lighting
IECC 2015 requires additional energy-efficiency measures based on choice of options,
including digital lighting control and a universal reduction of lighting power density.
Interior and Exterior
Automatic Lighting Shutoff
Interior Space Controls
Separate Control of Lighting
in Daylight Zones
Exterior Lighting Shutoff
The building complies if its total
connected power is no greater than the
interior lighting power allowance.
Exterior Lighting Power
Additional control methods can be
implemented to increase interior
lighting power allo wance ( 90. 1).
Continued from page 56