Your Vision subscription includes access to base area layers (such as postcode and administrative boundaries) which are used as building blocks and combined to create geographical areas (such as territories) as needed by your business.
Over time, these base area layers are updated. For example, new areas may be added, some areas may be deleted, and existing areas may be adjusted to accommodate the new and removed areas or simply as a result of improved accuracy.
This article provides examples of what you can expect when updating your data to a newer boundary release. We recommend reading this and Common questions on boundary updates before starting the update process.
Required time: 5 minutes.
What happens in a new boundary release?
There are three major changes to look out for when a newer boundary release becomes available. Let's start by taking a look at examples of these.
New areas are especially common in postal geography - where they are constantly updated to promote the efficient delivery of mail - but they can occur in any base area layer.
Let's look at an example of this in Nottingham, UK.
This is how the area looks in the older release. Focus on the area in the red box.
Now, look at the same area in the current release. Four new areas have been added (NG90 1, NG90 2, NG90 4, and NG90 5) with NG90 1 and NG90 4 (in the green area) sitting within the older NG7 2, and NG90 2 and NG90 5 sitting within the older NG9 1. Naturally, this also means that the boundaries for NG7 2 and NG9 1 have been changed to make way for these new areas.
The keen-eyed among you may have also spotted small boundary changes that we didn't cover in the previous example. Let's look at one of those more closely.
Focussing on two areas, NG9 1 and NG9 2, the older boundaries are red, and the latest boundaries are black. We can see some clear boundary differences (highlighted by points 1-4), but let's take a closer look at the changes in these two areas.
Here, we're displaying every part of the area that isn't identical between the two releases. You can clearly see the four points we highlighted in the previous image, but by removing all of the other detail from the map, it becomes apparent that almost every part of the boundary has been updated!
More often than not, these minuscule changes are the result of continual improvements to the accuracy of each boundary line. Let's take a look at what's happening at point 2 which we highlighted before.
By using satellite imagery, it's reasonably safe to assume that when the boundary for NG9 2 was drawn in the older release, there was a new development in the area which was going to be included within it. As that development progressed, more data was available, and so in the latest release, the boundary was adjusted to incorporate the buildings on the development rather than the construction area.
Sometimes, areas disappear in a new release of boundaries. This can happen for many reasons, the most common being:
- The area no longer meets its requirements for existence. These areas are usually absorbed into another neighbouring area.
- The area has been re-coded, and the designation has changed. Interestingly, unless this is part of a larger-scale recoding, this will then appear as a new area in the new release.
We're going to look at one particular example of a UK Postcode Sector (M90 2) being removed.
In the older release, you can see M90 2, but in the latest release...
...it's gone! M90 2 has been absorbed into M90 3.