Randall Whitehead, IALD, 6.12.04

Homeowners are now spending more energy and money on landscape design. They also now want to enjoy these exterior spaces at night, creating outdoor rooms for entertaining and allowing the yard areas to be enjoyed from inside the house. This is where effective lighting design comes into play.

One of the great benefits of exterior lighting is that it can visually expand the interior rooms of a residence. When there is no illumination outside, windows become highly reflective at night. This is known as the black hole effect. The windows end up reflecting the lights in the room, so that all the homeowners and their guests can see at night is their own reflection instead of the view beyond.

People often feel boxed-in at night when they are surrounded by these black holes. The rooms seem smaller than they actually are. The rule of thumb is to try and balance the amount of light inside and outside the house. This allows the windows to become more transparent, just as they are during the day. Psychologically too, people feel safer when they can see the yard area around them when looking out the windows. They also feel more visible and exposed inside the house when there is no lighting outside. To accomplish this, you don't have to light up the exterior like the White House. That type of illumination would come under the heading of security lighting.

Security Lighting
Security lighting and landscape lighting are two different things. Yet, often you will see people trying to use the same lights to perform both functions.

Security lighting is often simply a source of lighting that immediately floods the yard with a good punch of illumination. This is what people turn on when they hear a noise outside. The main objective is to provide enough light so that homeowners can see what is causing the disturbance outside.

Security lights should be mounted as high as possible under the eaves and aimed in different directions to provide good yard illumination. Some residential areas have "light pollution" regulations, requiring fixtures to be shielded to prevent glare that may disturb the neighbors.

Security lighting is optimally controlled by what is often referred to as a panic switch. This switch is located next to the bed in the master bedroom and in the bedroom of another responsible person in the household, such as the grandparent, au pair, or oldest child. A motion sensor can also control these security lights, but then neighborhood animals may trigger the lighting.

Security lights should not come on as part of the landscape lighting. There is nothing worse than driving up to someone's home, only to be assaulted by glaring security lights mounted on the corner of the house. As a guest you may feel like you've been caught in the middle of a prison break.

Landscape Lighting
Landscape lighting needs to be subtle. Attention should be drawn to the plantings, sculpture and outbuildings, not the luminaires. Decorative exterior luminaires such as lanterns can't do the job by themselves. They can easily overpower the facade of the house and the yard area if they are the only source of illumination. Typically you will see two lanterns flanking the front door and maybe a post light at the end of the driveway. These just become disturbing hot spots that leave everything else in silhouette.

Still, they play an important role in the overall lighting design. Their job is to create the illusion that they are providing all of the exterior lighting, when in reality, they should have no more than 25-watts worth of illumination.

Lighting Techniques for the Garden
There are many methodologies for landscape lighting from which you can choose. Here are some options for you to consider:

Uplighting - This can be a very dramatic way of lighting trees that have a sculptural quality to them. The luminaires can be ground-mounted or actually installed below-grade. These buried luminaires are known as well lights. Well lights have little or no adjustability, so they work best for mature trees. Above-ground directional luminaires have a much greater flexibility and therefore do a better job for younger trees as they mature. Use shrubbery to conceal the light source from view. A below-grade junction box will allow the luminaire to be closer to ground level.

Silhouetting or Backlighting - There are now fluorescent luminaires that do a good job of wall-washing, consuming a small amount of power with a long lamp life. Remember to specify a ballast designed for low temperatures if your project is located in a cold part of the country.

Downlighting - This type of lighting is to be used for outdoor activity areas. It's best to overlap the spreads of illumination to help reduce shadowing. The luminaires can be mounted on trellises, eaves, gazebos and mature trees.

Spotlighting - Use this technique minimally. Statues, sculpture or specimen plants deserve to be highlighted. They will tend to dominate the view as people look outside. Spot lights should be shielded to avoid glare if they are in direct view.

Path Lighting - This is one lighting technique that needs to be done judiciously. Too often we see walkways or driveways flanked with rows of pagoda lights as the only source of exterior illumination. This tends to look like an airport runway.

When a pathway light is needed, consider using an opaque mushroom-type luminaire that projects light down without drawing attention to itself. The luminaires should not exceed two feet in height. This, in combination with additional lighting sources will help create a comfortable exterior environment.

Spacing of path lights will depend on the style of the luminaire and lamp options. Many lighting showrooms now have landscape displays to help you make an informed choice.

Step Lighting - Fixtures can be recessed in the side walls or the steps themselves to illuminate the risers. This will provide safety as well as background fill illumination for the landscape design.

Moonlighting - This is the most naturalistic way of lighting an exterior space. The effect is as if the area were being illuminated by a full moon. A dappled pattern of light and shadow is created along pathways and over low-level plantings.

This is accomplished by mounting luminaires in mature trees, some pointed down to create the patterned effect and some pointed up to highlight the foliage canopy.

Controls - It's best not to dim exterior lighting. Many outdoor luminaires use incandescent sources. When incandescent lamps are dimmed, the light becomes more amber. The yellow cast makes the plantings look sickly. The whiter the light, the more healthy the plants look.

Decorative Fixtures - One aspect to consider when selecting an exterior lantern is the glass. Too often, they are chosen with a clear or beveled glass. The result is that at night people only see the light bulbs inside, instead of the luminaire itself. If you choose a luminaire that has a frosted glass, an iridescent stained glass, or a sandblasted seedy (bubbly) glass, then the volume of the lantern is seen instead of just the light bulb. If the lanterns are existing, it is possible to have the glass in them sandblasted. Often, mirror companies also do sandblasting as a sideline. Remember to have only the inside sandblasted; otherwise, if you do the outside, fingerprints will show because of the oil in our skin.

Layering these decorative fixtures with well-placed accent lights that do a combination of lighting effects will create an inviting outdoor environment that can be enjoyed from inside as well as outside.