Every building, by what it takes.
Every sprite the extension can draw on a New York lot. A day's height comes from its count, on one scale for everyone: 1 to 4 contributions is a brownstone or a shop, 5 to 14 a walk-up, 15 to 39 a tower and 40 or more a skyscraper. Landmarks are earned: they go to your best days in order, and only to a day at least as tall as the landmark itself.
The shelves, from bare lots to landmarks.
Within a shelf every tile is drawn at the same scale, so heights compare honestly. Hover or focus a tile to see when it gets built.