How to Let Light From an Opening Cover the Whole Basement

Paint the basement white, which will reflect the most light -- up to 85 percent. Whether the room is unfinished or not, putting white paint over gray concrete walls will immediately brighten the room by reflecting the natural light from the one opening. Using a semigloss rather than a flat paint will also add light reflection.

Cover the basement floor with white paint, as the gray concrete will absorb light. Choose a sturdier paint that can stand up to shoes, traffic and items being moved around in the basement -- such as furniture or boxes -- without flaking or peeling easily.

Monitor the light that comes through the opening to determine the best location for a mirror. This should be directly across from the opening. However, depending on the angle of the sun as it enters the basement, the mirror may need to be higher or lower on the opposing wall.

Hang a mirror across from the window. Choose a large mirror to reflect as much light as possible, rather than a small decorative mirror.

Place a long mirror on either side of the basement opening to reflect light back from the larger mirror on the opposite wall; these mirrors act as light bulbs from the reflected light.

Hang mirrors around the basement to reflect the sun's rays as they move around the room at different times of the day. Mirrors on opposite walls can provide a great deal of passive solar light if they are properly placed to catch the sun's rays as they stream in the opening.