Natural wood or fiberglass front doors?
from Rapid City Journal
No door compares in beauty to a finely finished natural wood door. Unfortunately, although most people think of wood as a good insulator, it actually is a poor insulator as compared to a steel or fiberglass door filled with insulation. If your current wood front door, or a new fiberglass one you are considering, has much glass as many door models do today, the door material becomes less important from an insulation standpoint.
7701 Las Colinas Blvd., Ste. 800, Irving, TX 75063