As the earth travels around the sun, the slant of the light changes. It also changes in temperature and intensity. This constant change of light over surfaces is what artists and architects call “the play of light.” It is is something we want in our churches, a gift from the Creator.
Churches traditionally have been built (whenever possible) facing east, ad orientum, towards Jerusalem and the rising sun, symbolic of Christ’s coming again in glory.
Natural light from the sun travels about 93 million miles to reach us. Containing within it all the colors of the spectrum, it also reveals the color in our world. It also reveals the sculptural qualities of objects, including arches and statues.

Light is not what we normally think of as one of the materials used in designing a church (such as marble, slate, porcelain, wood, paint, etc.) because it is not made of matter. Light is a form of energy, or electromagnetic radiation visible to the human eye. However, great architects and artists shape matter based on its relationship to light. So at the very least, we should observe the light as it plays in our churches before we make major decisions about design and materials.
There are aesthetic reasons to use natural light: the artificial “gymnasium” feel of some post-modern buildings has not been an aesthetic triumph.
There are also environmental reasons to use natural light: better stewardship of the earth.
There are economic reasons to use natural light: at the present, it is free of charge. No monthly bills from the Creator for using His light which illumines all things. (However, we have to design and pay for the larger windows, making sure they are energy efficient, suited to the climate, etc.)
There are health reasons: according to medical research, natural light may improve our vision, enhance our mood, relieve depression, and aid in restful sleep (at the end of the day), and has other benefits as well.
What should you do if your church was built with inadequate natural light? It may be worthwhile to consider adding windows, especially if yours is a contemporary or mid-century church with inadequate natural light.
What if engineering, design, or budget considerations do not allow you to let in more natural light?
Artificial lighting should be designed using the liturgical and aesthetic knowledge of the designer, the technical knowledge of a lighting engineer, and the needs of the priest and parishioners.
Consideration should be given to the design of the fixture itself, the number and placement of the fixtures, along with temperature and intensity of the light that they produce. The warmth or coolness of light has a dramatic impact on our sensations and moods, as dramatic as the difference between the warm light of a fireplace and the cold light of the high beams of a sports car. We want lighting that will illumine and enhance the liturgy and be conducive to prayer throughout the day. Artificial light may be used to highlight the Sanctuary, Tabernacle, Altar, the Stations of the Cross, statues of patron saints, and other areas of the church.
But there is another aspect to church lighting to consider.
MYSTERY.
We don’t want our churches to be difficult to navigate, unsafe, or scary. It is necessary to be concerned with safety. And we need to see our missalettes!
It may be argued that many of our church designs and renovations have neglected the element of mystery when designing with artificial lights. If we simply replace the old artificial lights with new artificial lights, we may have an environment that is sterile. Too much can be worse than too little.
In certain parts of the church, such as shrines, we would like to be able to light our candles in relative darkness, as we offer our prayers.
We would like to experience the mystery of the light against the darkness. To quote Saint John the Evangelist: “The light shines in the darkness, and the darkness has not overcome it (John, 1,4-5).”

Light is radiance. In our post “What Makes a Church Beautiful?” we discussed radiance as one of the three things that makes a church beautiful.
https://www.architectmagazine.com/technology/lighting/the-benefits-of-natural-light_o