# Map data

The address points, boundaries, and statistical layers behind every Prenso map, and how to use them when planning an area.

Every count, route, and boundary in Prenso comes from real data rather than an
estimate. This page covers what's available and when to reach for each layer.

## Addresses

The foundation. Prenso holds the official address point for every property in
the countries it supports, sourced from the national address registers:

| Country     | Source                                 |
| ----------- | -------------------------------------- |
| New Zealand | Land Information New Zealand (LINZ)    |
| Australia   | Geocoded National Address File (G-NAF) |

Each address carries its number, street, suburb, and a precise location. That's
what makes the two things Prenso is for possible: an exact count of what's
inside an area, and a route that walks streets in house-number order along one
side at a time.

These registers are maintained as new properties are built and old ones removed,
and Prenso reloads from them, so new subdivisions turn up in your counts without
anyone having to notice them.

> **Why counts beat estimates**
>
> Ordering leaflets from a guess means either a shortfall halfway down a street
> or a box left over. Both cost more than the ten seconds it takes to draw the
> area and read the number.

## Boundaries

Boundary layers are published administrative and statistical areas you can turn
on as an overlay, or use to build a map directly.

### Statistical areas

Statistical Area 1 (SA1) units are the small building blocks national
statistics agencies use — typically a few hundred people each. They're the
most useful layer for delivery planning, for three reasons:

* They're **already about the right size**. An SA1 is usually walkable in one
  outing without splitting.
* They **follow real edges**. Their boundaries respect main roads, waterways,
  and reserves, because they were drawn by people who understood the terrain.
* They're **repeatable**. Build maps from SA1s and your patches look identical
  next quarter, so coverage comparisons actually mean something.

### Electorates

Electoral boundaries are available as an overlay for orientation — confirming
which side of a line a street falls on, or setting a workspace's geographic
scope.

You wouldn't build a delivery map from one. An electorate holds tens of
thousands of addresses, which is several months of walking rather than an
afternoon, so Prenso doesn't offer map creation on that layer.

## Using layers while planning

In **Maps → Explore**, the layer selector controls what's drawn. You can stack:

* One or more boundary layers, for context.
* Your existing delivery maps, so you can see what's already covered.
* Your [sites](/docs/workspaces/sites), so signage and delivery planning happen
  on the same screen.

Boundary layers appear as you zoom in. Fine-grained layers such as SA1 stay
hidden at national zoom — several hundred thousand polygons on screen at once
would be unreadable as well as slow.

## Workspace scope

A workspace can be restricted to a set of boundaries, so its maps, searches, and
address data stop at that edge. Where you run one workspace per electorate or
council area, this makes planning into someone else's patch impossible rather
than merely discouraged.

See [Workspaces](/docs/organisations/workspaces#geographic-scope).

## Next steps

- [Leaflet maps](/docs/workspaces/leaflet-maps) — Turn a layer selection into a walkable route.

- [Getting started](/docs/getting-started) — Build your first map end to end.