7. Install daylighting as an alternative to electrical lighting.

Daylighting is a way to draw in natural light from outside to illuminate the home's interior. It can be achieved using the following approaches:

• skylights. It’s important that they be double-pane or they may not be cost-effective. Flashing skylights correctly is key to avoiding leaks.

• light shelves. Light shelves are passive devices designed to bounce light deep into a building. They may be interior or exterior. Light shelves can introduce light into a space up to 2½ times the distance from the floor to the top of the window, and advanced light shelves may introduce four times that amount.

• clerestory windows. Clerestory windows are short, wide windows set high on the wall. Protected from the summer sun by the roof overhang, they allow winter sun to shine through for natural lighting and warmth.

• light tubes. Light tubes use a special lens designed to amplify low-level light and reduce light intensity from the midday sun. Sunlight is channeled through a tube coated with a highly reflective material, and then enters the living space through a diffuser designed to distribute light evenly.