NRDC's This Green Life
A Journal of Sorts
OCTOBER 2004 / Links updated 2013

For the last several months, we've been living in a construction site while renovating our loft. Though we've been inconvenienced mightily, we've also enjoyed seeing the new place materialize bit by bit. The lighting has worked out particularly well, achieving both our aesthetic and environmental goals.

It doesn't seem as if lighting would have much environmental impact, but it does. Nationwide, home lighting accounts for nearly 10 percent of residential electricity consumption. Interior windows in our loftThis matters because electricity is the single largest source of global warming gas emissions in the U.S., as well as a major contributor to smog.

The bottom line: you can help cut air pollution by using less electricity to light your home. One way is by designing your home to render artificial lights less necessary, by making better use of natural light. Presumably, this is what most people did in the days before the light bulb. Another is using more efficient lights that operate with less electricity.

Here are some specific measures you can take:

1) Locate furniture to make use of natural light. In my office, for instance, we set the desk back in a corner at right angles with one of the windows. I do paperwork at the front of the desk where the sun shines directly. The monitor is situated at the rear, where it's shaded, to avoid glare. There is no need for artificial light on clear or partly cloudy days. On summer afternoons, I pull a shade down halfway to keep cool.

2) Use task lighting. Activities that involve detailed work, such as cooking or writing, require bright illumination. Rather than light the whole room to the high level required, put extra lamps in the workspaces -- just as you'd put a reading lamp next to a bed. That way, additional light is available when needed but not used unnecessarily.

3) Install interior windows in the walls between one room and another. This increases light flow in your home. If you're unlucky enough, as we are, to have inner rooms with no windows to the outside, you'll find that interior windows make a huge difference. They don't eliminate the need for artificial light, but do lessen it.

4) Paint surfaces in light colors. Dark colors eat up the light, while light colors reflect it. Our old kitchen, which was mauve, was like a cave. In our new hay-colored kitchen, the light bounces off all the surfaces. On sunny mornings, no artificial lights are necessary, though the kitchen is an interior room that only receives natural light via interior windows.

5) Use mirrors to reflect light. This is an age-old technique, not only to lighten a room, but also to make it seem larger. We used a mirror, set at right angles with an outside window, to reflect light down a hall and into our windowless family room.

6) Install a skylight. This isn't something we could do, since we live on the lower floor of an apartment building, but it's a great way to flood the right kind of house with natural light.

7) Put energy-efficient compact fluorescent bulbs (CFLs) in your most frequently used light fixtures. This is something everyone can and should do. CFLs use a third to a quarter of the energy that incandescent bulbs do to produce the same amount of light. And they don't have any of the disadvantages associated with fluorescents from the old days. They turn on instantly, don't buzz or flicker, come in a range of light tones (including the warmer tone associated with incandescent bulbs) and screw into standard light fixtures.

According to the Energy Star website, if all American households replaced their five most heavily used incandescent bulbs with energy-efficient lights, it would be like taking 8 million cars off the road for a year -- or closing down 21 power plants. The benefit? Keeping more than 1 trillion pounds of global warming gases out of the air.

From my perspective there's no downside to any of these energy-reducing measures -- only the pleasure of living in a light, bright, well-designed home.

—Sheryl Eisenberg


The challenge with interior windows is providing for privacy as well as light flow. There are several options:

Use translucent windows. Try patterned glass, which is a beautiful architectural element. In our bathroom, we installed one pebbled and one fluted window. Both allow plenty of light through, but obscure the images on the other side.

Use clear windows, but mask the view with loose-weave curtains. Even when closed, they still let some light in. We used lacy bistro-style curtains in our bedrooms.

Put transom windows over your doors. They're good for air circulation as well as light.

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Family photos
Sheryl Eisenberg, a long-time advisor to NRDC, posts a new This Green Life every month. Sheryl makes her home in Tribeca (NYC), where—along with her children, Sophie and Gabby, and husband, Peter—she tries to put her environmental principles into practice. No fooling. Read more about Sheryl.

Interior windows (at left) in our loft. One has lace curtains to shield the view. The other uses fluted glass. Both let light stream into other rooms.

NRDC's Santa Monica office
Daylighting. This new-old movement in building design seeks to illuminate interiors with natural light, without creating excessive heat or glare. Daylighting inspired us in our loft renovation and was used extensively in the design of NRDC's Santa Monica office, pictured in the architect's drawing above.


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Daylighting Clearinghouse

Energy Savers: Daylighting

Change a Light, Change the World

How Energy-Efficient Bulbs Compare with Traditional Incandescents

CFL Savings Calculator

How Light Bulbs Work

Global Warming 101

CFLs are the efficient way to go.

What a waste! The standard incandescent bulb (which hasn't changed significantly since Thomas Edison invented it) wastes 90 percent of the energy it uses producing unwanted heat.

What's a watt? Surprise! It's not a measure of light output, but of energy used (1/746 horsepower). Look at the lumens if you want to find out how much light a bulb produces.

The incandescent-CFL equation. CFLs use about a quarter to a third of the watts that incandescent bulbs do to produce the same amount of light. So if you're replacing a 75 watt incandescent, look for a 20 to 25 watt CFL. To confirm that the light output is the same, compare the lumens listed on the packages.

Cheaper in the long run. Though more expensive to purchase than incandescent bulbs, CFLs save money in the end because they use one-fourth the energy of incandescents and last four to six times longer. You only need to replace them every four to ten years.

Sheryl Eisenberg is a web developer and writer. With her firm, Mixit Productions (, she brought NRDC online in 1996, designed NRDC's first websites, and continues to develop special web features for NRDC. She created and, for several years, wrote the Union of Concerned Scientists' green living column, Greentips, and has designed and contributed content to many nonprofit sites.

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