Lighting
For the most efficient and aesthetically pleasing design strategy, use the three basic layers of lighting:
- Task lighting: putting high light levels only where we need it
- Ambient lighting: for circulation and to control contrast
- Accent lighting for points of interest. Optional but important for providing visual interest.

LIGHTING CONTROLS
- On-off toggle.
- Dimmer controls. Dimmers are a good way to help the lighting be more adaptable and they extend the life of incandescent bulbs considerably.
- Occupancy sensors: They reduce lighting energy use by turning lights off soon after the last occupant has left the room. Occupancy sensors must be located where they will detect occupants or occupant activity in all parts of the room. There are several types of occupancy sensors:
- Photosensors to turn off lights during daylight hours.
- Motion detectors to activate security or utility lighting when needed.
- Ultrasonic sensors detect sound. - Infrared sensors detect heat and motion.
- Timers and other controls to turn decorative lighting on and off.

Efficiency of the light bulbs:

Points to think about:

INDOORS
-Maximize the use of day-lighting - which is also the main goal of Passive Solar design.
-Install fluorescent light fixtures for all ceiling and wall-mounted fixtures that will be on for more than 2 hours each day (including fixtures in the kitchen, living room, bathrooms, halls, bedrooms, and other higher-demand locations).
-Install dedicated compact fluorescent fixtures, rather than CFLs in incandescent fixtures, so that fluorescent bulbs continue to be used for the life of the house.
-Use CFLs in portable lighting fixtures that are operated for more than 2 hours a day.
-Use light wall colors to minimize the need for artificial lighting.

OUTDOORS
-Security and utility lighting does not need to be bright to be effective.
-Use fluorescent, HID, or low-pressure sodium lights or LED lights, unless incandescent lights are automatically controlled to be on for just a few minutes each day.
High Intensity Discharge (HID) lighting (cars & street lights) Light is emitted from an arc discharge between two closely spaced electrodes inside a small quartz glass tubular envelope capsule. Light Emitting Diode (LED) (Since 1962 in TV and radio, later in flashlights, but now around the home) A semiconductor device which converts electricity into light. A blue indium gallium chip with a phosphor coating is used to create the wave shift necessary to emit white light from a single diode
-Consider incandescent flood lights with combined photo-sensors and motion sensors in the place of other security lighting options.
-Make sure outdoor light fixtures have reflectors, deflectors, or covers to make more efficient use of the light source and help reduce light pollution.
In most applications, use:
-Photosensors to turn off lights during daylight hours.
- Motion detectors to activate security or utility lighting when needed.
- Timers and other controls to turn decorative lighting on and off.

"Good lighting can make an ordinary room look extraordinary and functional."

Ambient light and task light are the basics of lighting, while accent light points of interest are highlighted to give the space extra visual appeal. This method of layering the light is important for achieving positive results in all types of living and working spaces.

Start with the task areas. These are best lit with bright, shadowless light. You want to get the fixture close to the task area (in kitchens this would be counters, sinks, and tabletops), or use hanging, or pendant style fixtures to bring the light close to the task area. If this is not possible, you can project light from the ceiling (using either track or recessed fixtures) onto the task area.

Ambient light is the general, overall light that fills in shadows, reduces contrast, and lights vertical surfaces to give the space a brighter feel. Ambient light is what you need for casual activities in your rooms. If the room has light colored surfaces and lots of windows, you should have plenty of natural ambient light during the day. But rooms used from before dawn until after midnight can't rely on windows and skylights. Fluorescent tubes are well suited to the job of providing ambient light. They provide broad, even illumination and their efficiency makes it possible to really fill the space with light without using a lot of power or generating too much heat. You can put the tubes in a central fixture, but you may want to try some other strategies, like placing them on top of the upper cabinets to indirectly reflect off a light colored ceiling. If you have at least 12 inches of space from the top of the upper cabinets to the ceiling, this is an inexpensive way to brighten up a room.

Accent lighting is what gives our space a third dimension, adding to the quality of the space. Accent lighting is used sparingly on those special home objects that we want people to notice and admire. Accent lighting is usually done with spotlights, and the MR16 lamp mentioned earlier is one of the best. You may be lighting artwork, architectural details, collectibles, or food presentation areas. Remember, good lighting can make an ordinary kitchen look extraordinary, and bad lighting can make an extraordinary kitchen unworkable.

Lighting for living spaces (living rooms, dens, or bedrooms) can actually be more difficult to design than lighting for task areas (kitchens, home offices, and baths). The lighting must be flexible for the many and varied activities in these rooms. The general emphasis is on atmosphere and mood, with the occasional need to accommodate a task (such as reading a book, packing for a trip, or late night cleaning).

A great way to add ambient light is with indirect fluorescent lights. You can create a cover or light-shelf on the walls to bounce light off of the ceiling. Lighting the ceiling helps expand the space and can add visual interest to the room itself.

Put light just where it is needed. Portables have one main advantage over permanently installed fixtures - they are, portable. We can move them around and play with the design and mood of a space. Portables also allow us to move the light close to a task area. This can increase the light on the task and also save energy in the process.

Portable luminaries are a common and versatile type of lighting often used today. Table lamps, floor lamps, desk lamps, and torchieres are examples of portables.

The torchiere is also used for ambient lighting. It is a tall, open floor lamp that directs almost all of its light upward to reflect off of the ceiling, filling the room with indirect light. The torchiere may seem to disappear and become a platform for an unseen light source. Most torchieres found in retail stores use halogen lightbulbs. These bulbs use 300 watts or more and are expensive to operate and can be unsafe due to the heat generated by the bulb. A number of manufacturers are now producing torchieres that use energy efficient Compact Fluorescent lamps. These CFL torchieres are a great way to efficiently produce ambient light for a room.

Energy-efficient lighting design principles:
- More light is not necessarily better. (Human visual performance depends on light quality as well as quantity.)
- Match the amount and quality of light to the performed function.
- Use task lights where needed and reduce ambient light elsewhere.
- Use energy-efficient lighting components, controls, and systems.
- Maximize the use of day-lighting
- Security and utility lighting does not need to be bright to be effective.
- Consider incandescent flood lights with combined photosensors and motion sensors in the place of other security lighting options.
- Establish ambient illumination at minimum acceptable level.
- Increase the efficiency of lamps, ballasts, and fixtures.

What every home-owner can do:
- Install fluorescent light fixtures for all ceiling- and wall-mounted fixtures that will be on for more than 2 hours each day (including fixtures in the kitchen, living room, bathrooms, halls, bedrooms, and other higher-demand locations).
- Use CFLs (Compact Fluorescent Lighting) in portable lighting fixtures that are operated for more than 2 hours a day.
- Use light wall colors to minimize the need for artificial lighting.
- Use fluorescent, HID, or low-pressure sodium lights unless incandescent lights are automatically controlled to be on for just a few minutes each day.
- Make sure outdoor light fixtures have reflectors, deflectors, or covers to make more efficient use of the light source and help reduce light pollution.
- Reduce light levels where there are no visual tasks. Provide minimum light necessary for safety, and aesthetics.
- Reduce light levels for visual tasks where those levels are currently excessive.

If recessed lights are used in a ceiling with an unconditioned space above it, use only Underwriters Laboratory (UL) approved fixtures that are airtight, are IC (insulation contact) rated, and meet ASTM E283 requirements.

Source: Illuminating Engineering Society of North America IES & Eric Strandberg LC, Lighting Design Lab

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Note: All lamps are rated in Lumens
Efficacy (efficiency) = Lumens/Watt
Distribution of light on a horizontal surface = Illumination in Foot-candles
A foot-candle = one Lumen distributed over 1 sq Ft
30-50 Foot-candles: OK for office & homes
200-500 Footcandles: OK for sewing
5-20 Foot-candles: OK for security light