What a 3 m x 3 m UPCS Cell Means

Every UPCS code corresponds to a square grid cell that measures 3 metres by 3 metres. In practice, that is a little smaller than a typical car parking space, which is small enough to distinguish a gate or a doorway from its neighbours.

What 3 m x 3 m looks like

Nine square metres. Think of a small parking bay, a large doorway with the area in front of it, or a compact market stall. A typical house plot will cover several cells, and a block of flats will cover many. A narrow street may be only one or two cells wide.

What that means for finding a place

• A gate or door is identifiable. A pin in the correct cell is near enough that a driver or visitor will see the entrance.
• Neighbouring properties have different codes in most cases, because plots are generally larger than a cell.
• A large compound has many codes. Choose the one at the entrance that matters.

What it does not mean

A code identifies a cell, not a point within it, and not a building. Several flats or offices stacked in a tall building share the same cell. The code also does not tell you about floors, doors or internal layout. Use a note for that; the code itself always leads to the exact square.

Choosing the point

1. Zoom in on the map until the grid appears; with the embeddable map, the grid is shown from zoom level 18.
2. Pick the key spot, such as the gate where a vehicle should stop.
3. Avoid cell edges for a point right on a boundary; a position slightly further in is more robust to small GPS drifts.
4. Check the pin against the building. See how to verify a digital address.

Boundaries

Points on opposite sides of a cell boundary have different codes, even if they are very close. That is a general feature of grid systems; see grid-based addresses explained. If two people choose the same entrance but click slightly different spots, they might end up with neighbouring codes. For deliveries, agree on one code and use it.

Why 3 m

Any cell size is a compromise between code length and precision. A cell of a few metres is small enough to be useful at a door while keeping the code short. See what makes a good location code.