Daylighting

Daylighting

Daylighting is the strategic and energy efficient use of windows and skylights to bring sunlight into your home. Many people prefer daylight to artificial light because it makes them feel more connected to the outdoors.  In addition to reducing energy costs, it can also reduce stress and contribute to health and emotional well-being.

Benefits of Daylighting:

Daylight significantly improves the quality of light in indoor spaces, allowing for better vision.
Our eyes turn daylight into electric impulses that trigger the release of serotonin in our bodies.  Serotonin is necessary for emotional well-being.
Ultraviolet light from the sun creates Vitamin D through our skin, producing calcium for healthier bones and teeth.
Working by daylight results in less stress and discomfort than working by artificial light.
Artificial lighting is responsible for almost 15% of a household’s electricity use.  By minimizing the use of artificial lighting, day lighting reduces energy consumption and costs.

Quick Tips:
Energy-Saving Tips
What are my Options?

Energy-Saving Tips

Daylighting Tips:

Use light-colored, loose weave curtains on your windows to allow daylight to fill the room.
Decorate with lighter colors that reflect daylight.
Consider light wall colors to minimize the need for artificial lighting.
In winter, open curtains on your south-facing windows to allow sunlight to naturally heat your home, and close them at night to reduce the chill you may feel from cold windows.

Installing a skylight can provide your home with natural light and warmth.  When properly selected and installed, skylights can reduce your heating, cooling, and lighting costs. Tubular skylights also reduce your use of artificial lighting.

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What are my Options?

Daylighting in Existing Homes. South-facing windows are best for daylighting.  They take in a lot of sunlight in winter, warming the home, and little direct sunlight in summer.  North-facing windows are also well-suited to daylighting since they admit natural light without producing much glare or solar heat gain in summer.  East-facing windows admit a lot of light the morning and west-facing in the evening, but they also tend to allow glare and solar heat gain in summer and account for some heat gain in winter.

While windows permit daylighting and good views, unless well designed and constructed, windows can be a source of heat loss and gain during the winter and summer, respectively.  A window should not exceed fifteen percent of the wall’s area in size, unless the home has been specifically designed for passive solar heating.

Skylights. Skylights can be strategically positioned according to the room’s day lighting needs.  Skylights on north-facing roofs admit relatively constant, cool light.  East-facing skylights admit the most light and heat in the morning, while west-facing skylights allow for maximum light and heat in the afternoon hours.  Skylights on roofs that face south are best for winter solar heat gain, but they often lead to unwanted summer heat gain.

There are ways to reduce this heat gain, such as: Selecting special glazing, adding an adjustable window covering, or placing the skylight under a tree that creates shade in summer, but loses its leaves in the winter.

As a rule, skylights should measure no more than five percent of the room’s floor area if the room has many windows and no more than fifteen percent of the room’s floor area if the room has few windows. 

Tubular skylights (light pipes). Tubular skylights can also save energy and money by reducing electricity use. They direct sunlight from the roof into the home through a highly reflective tube that fits between the rafters and ceiling joists. The reflective tube guides the sunlight to a diffuser lens at the ceiling level, which spreads light evenly throughout a room.

Tubular skylights are usually cheaper (cost ranges from $150 to $600) and easier to install than regular skylights. Also, unlike regular skylights, they do not cause condensation or ultraviolet damage to carpets and furniture.

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What do I ask a contractor?

Daylighting for New Homes. If you are building a new home, consider daylighting as part of your whole-house design.

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