ANSI/ASHRAE/IESNA Standard 90.1 2007

90.1 is an American National Standard (ANS). It is a national voluntary consensus standard developed under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the Illuminating Engineering Society of North America (IESNA)

Some jurisdictions have adopted 90.1 as a local legal requirement. Check your jurisdiction. In fact most energy codes in the USA are based upon 90.1

The original Standard 90 was published in 1975 and revised editions were published in 1980, 1989, and 1999. As technology and prices began changing more rapidly, the Standard was placed on continuous maintenance, with a full new Standard published every third year.
Not every jurisdiction uses the current year. Check the jurisdiction in the project location.

The purpose of the Standard is to provide minimum requirements for the energy-efficient design of buildings.

Scope

A) New buildings
B) Additions to Existing Buildings

Exception: When the addition itself cannot comply, "trade-offs", which allow modifications to the existing building may be considered.

Lighting is covered in "Section 9"

There are Two primary compliance paths;

Paragraph 9.5 covers Building Area Method (See Attached Table)   Table 9.5.1
Add up the total  area, then multiply by the maximum listed for that type.
      Most areas are limited to @ 1 watt/sq. ft.

Paragraph 9.6 covers Space by Space method (See Attached Table)   Table 9.6.1
Look up each space, then multiply by the maximum listed for each.

Note:  this may require more calculation work but will probably allow more w/sq ft    

       Example:   Religious Buildings
                      Worship Pulpit, Choir      2.4  watts/ sq ft.
                      Fellowship Hall              0.9  watts/ sq ft.

There is also one supplemental compliance path;

Paragraph 11 covers Energy cost Budget Method
This method  basically uses an established computer program such as DOE-2 or BLAST which will simulate (or calculate) based upon its methodology and the components that are input to the program.  All this works fine as long as the energy efficiency of the specified items are equal or less than the items in the program.

There are some NOTABLE expections (applications that are NOT to be counted in the maximum w/sq. ft. allowance)

a) Accent or Display lighting that is an essential element of the space,such as in a gallery.
b) c) d) e) f) lighting in a case, such as a glass freezer.
g)  Lighting in spaces used by the visual impaired or other age or medical related issues.
h)  Lighting in retail display areas.
i)  Historic landmarks.
j)  Lighting that is an integral part of directional signage.
k)  Exit signs.
l)  Lighting used for educational demonstration systems.
m)  Lighting for theatrical stage or performance area.
n)  Lighting for television broadcast, film, or video production.
o)  Casino gaming areas.
p) Task lighting, especially furniture-mounted, controlled by separate or automatic shutoff.

Hint: Study and learn the Exceptions. They can enrich your overall Lighting design & installation.


Exterior Lighting

Exterior building features, including facades, entrances, exits and loading docks  (exception: life safety statute requirements & decorative gas lighting). All exterior building grounds lighting through the building's electrical service.

Lighting Control is Mandatory for buildings larger than 5000 sq. ft.

a) Scheduled bases. Time-of-day operation control device that will turn off the lighting at specific time. Ok to use in areas 25,000 sq ft or less.

b) Occupancy sensor. Turning off the lighting within 30 minutes.


9.4.1.4 Additional Control

a)  Accent or Display lighting shall have a separate control.
b)  Lighting in a Case shall have a separate control.
c)  Hotel/Motel rooms shall have separate controls.
d)  Task Lighting shall have a separate control device.
e)  Nonvisual lighting such as for food warming shall have separate control.
f)  Demonstrational / Educational demonstrational lighting shall have separate control.

http://www.ashrae.org/

http://www.aboutlightingcontrols.org/education/papers/2008_ashrae2007.shtml

Multi Levels of Lighting

Note:  Many codes today, do not specifically require  "Bi-Level Switching" however, you can achieve a tremendous energy savings for your client with multi levels of lighting.

Early applications used occupancy sensors that  seemed to be set up in such a way that it is now part of urban legend, "people's lights would turn off while sitting at their desks talking on the phone" 

Today, most sensor applications, start with a minimum base level (rather than dark)  then employ a sensor system for the main lighting system and then add task or accent lighting to round out the layering of the design.

Comment:

The ASHRAE/IESNA 90.1  standard gives maximum watts per sq ft (of lighting) for various categories of occupancies.

It does not tell you how to light the area so people see well

It does not encourage systems that will help the owner/occupant save energy, once in the building

It does not encourage systems that will shed "peak demand" rate charges