Homeowners love to let the sun shine in.

But builders and architects know that flooding rooms with natural light—through windows, skylights, solar tubes, light wells, clerestories, and other building-envelope penetrations—can create problems, especially in northern and southern regions where heat loss or heat gain often accompany any increase in glazing. Bringing natural light deep into a home’s interior, whether for new construction or renovation, also can require difficult and costly building efforts but can reap huge rewards in efficiency and comfort if implemented effectively.

Benefits of Natural Light

Natural light is not only desirable to most occupants, it may be essential to their lifestyle and even well-being. In Christopher Alexander’s groundbreaking A Pattern Language, the architectural faculty at the Center for Environmental Studies (University of California, Berkeley) observed that occupants of buildings typically gravitate to rooms that have natural light on two sides. According to the authors, “This pattern, perhaps more than any other, determines the success or failure of a room. The arrangement of daylight in a room … is fundamental.”

An abundance of natural light throughout the day also can help offset a home’s energy loss or energy load by reducing use of artificial lighting. And passive solar design, which relies on careful site orientation, shading, and window placement, often includes daylighting strategies to reduce energy use. Striking a balance between natural and artificial lighting in residential design is often “a combination of art and science,” says Carson Looney, a principal in Looney Ricks Kiss Architects, headquartered in Memphis. “Daylighting is about creating that wonderful environment,” he says. “People say they want more windows, but what they really need is wonderfully balanced lighting.”

Most people spend more time at work than in their homes during daylight hours, Looney says, so he recommends that his clients “don’t try too hard or spend too much on natural lighting for economic reasons. I tell them to do it for their aesthetic comfort and enjoyment. It’s more about the quality of light than the quantity of light.”

Anne Fougeron, who heads her own architectural firm in San Francisco, says she tries to make the most of natural light “whenever and wherever possible” in residential and commercial projects. Understanding how sunlight and shadow will impact the structure when the building is sited on the lot is a critical step in her design process, she adds.

“First, you need to know where the light is coming from—you don’t just assume it comes from somewhere,” she says. “A big mistake people make is not being careful about how the glazing is going to interact with the light, how the glazing ‘operates’ year-round. You have to ask: Will it be too public, or too hot in summer?”