The doorway’s small step can be a large part of somebody else’s route.

One shallow step is invisible to most people and decisive for others. For someone using a wheelchair, a frame or a pram, that lip at the threshold is not a detail but a fact about where the day can go, and routes get planned around it long before anyone arrives. A place can be open and still closed by four inches of stone.

Notice the thresholds on a street you use. If a step belongs to somewhere you have influence, a portable ramp or a marked side entrance changes who the door is for. If it does not, mentioning it to whoever owns the building still matters.