The company's 24-gauge, Energy Star-qualified steel doors offer an aluminum exterior frame in a wide range of colors. They feature a rot-resistant design, which allows the frame to sit on top of the threshold to prevent water absorption, states the firm. A foam core offers up to five times the insulating value of wood, the manufacturer claims. The primed doors can be predrilled for hardware. A variety of embossed panels and decorative glass options is available. 800-374-4758. www.pella.com.