Door installation requires accurate measurements, correct door selection, frame inspection, hinges, hardware, weatherstripping, sealant, and careful adjustment. The doorway must be level, square, and strong enough to support the new door.

For exterior doors, sealing around the frame is especially important to prevent drafts and water intrusion. The door must be aligned so it swings properly, closes tightly, and locks securely. Hardware such as handles, deadbolts, hinges, and thresholds must also be installed correctly. Professional installation helps prevent sticking, gaps, weak security, and early wear on the door system.