Steel
Premium-quality steel doors feature outer layers of heavy-gauge steel that's embossed to mimic wood grain or stucco. Overlays, such as moldings and cross-buck designs, give the look of carriage doors. Foam cores add strength and insulating values.

Most steel doors can be purchased with factory-applied finishes. Although color choices are somewhat limited, these doors are virtually maintenance-free. Also, steel can be ordered primed, or painted to match house colors.

Heads up: Steel can dent.

Insulating value: R-6 to R-17

Cost for a 16-by-7-foot double door: $750-$3,500.