What could it mean?
A door is a decision that has not been made yet. Whether it opened is the reading.
— Vera
A door is one of the smallest images in a dream and one of the most loaded, because it does only one thing: it separates here from there, and it can be in exactly two states. Dreamers almost never remember a door that simply worked. What they remember is the one that was locked, the one they had never seen before, or the one they did not go through — and those three are different dreams entirely.
Locked doors are most often connected to something wanted and out of reach, and dreamers usually report frustration rather than fear. A door you had not noticed before is the opposite and is reported with something closer to excitement — people connect it to possibilities they had not considered. The third common version is the open door somebody did not go through, and that one tends to appear where a choice is available and not being taken.
The door is the threshold itself, and every tradition with rites has one: the gate you must be admitted through, the lintel you do not step on, the key that has to be earned. It always implies somebody or something that decides. A door with no handle on your side is a very old image and means what it looks like it means.
Read as a passage rather than an object, the door is about readiness. Many traditions hold that the door opens when the one standing at it is ready, which is why a dream of waiting at one is not treated there as failure.
Your dream is more than one symbol.
A door that was locked and a door you had never noticed are opposite dreams. Tell Vera which one you found.
Interpret my dream →What does a locked door mean in a dream?
It is the most reported version and it is usually connected to something wanted and currently out of reach. What you did about it — searched for a key, knocked, gave up, went round — is the detail that changes the reading most.
What does it mean to find a door I had never seen before?
New doors, especially in a house you know, are one of the most striking dream images people report, and usually with pleasure. They tend to be connected to a possibility that had not been considered. Whether you went through is worth as much as the finding.
What does it mean if I did not go through an open door?
An open door not taken is a quiet version and easy to overlook when writing the dream down. It tends to appear where a choice is genuinely available and not being made. What kept you is the reading — a reason, or nothing in particular.
What does it mean if somebody was behind the door?
Anybody at a threshold carries weight in the image, because a doorway is where arriving and leaving are the same shape. Who it was, and whether they came in or stayed there, says more than the door.
Why do doors turn up in so many dreams?
Like stairs, a door is a setting more than a subject, so it often appears without being the point. If doors keep turning up, what changes about them from night to night is usually where the meaning sits — and that is exactly what you cannot see without a record of your earlier dreams.