UK Area Polygon Mapping in Tableau

Ever since Tableau introduced filled maps in version 7 we’ve repeatedly been asked about filled maps in the UK and why it’s limited to just England, Scotland, Wales and Northern Ireland.

Our understanding is there are two main reasons. First is installation size and keeping Tableau as lean as possible. I don’t know if you’ve notices but for such a small country the UK is split into many different areas. Even if you just take the first one or two letters of the postcode as a grouping method there are 124 different shapes covering the country! That compares to only 50 states to cover the whole of the United States of America and from a country that would only rank as the 12th largest state in America.

The second reason comes down to complexity. Tableau try to maintain simplicity throughout the product, the first question asked when a new function is developed is “Is it as simple as it can be?” I can imagine the poor developers working on filled maps thinking “OK we’ve covered most of the globe using the hierarchy Country – State – County – City but the UK, that doesn’t seem to fit.” If we take a look at how the hierarchy applies to the UK then it would align something like:

You can see how the alignment can become very confusing very quickly. This isn’t to say that Tableau won’t solve it some day, after all they have developers many times smarter than myself working for them.

How The Information Lab Can Help

Like many other challenges in Tableau there is always a way to achieve the visualisation you’re looking for. All you need is a method and some data. For the method we have a video taking you step by step through the process (see the bottom of this post) and as for the data we’ve done as much of the hard work as we can so you don’t have to. If you don’t see the UK boundary data you’d like then please get in contact and we’ll help you out as best as we can.

UK Boundary Polygon Data

Creating Polygon Area Maps in Tableau