Why you shouldn't navigate by postcode

Thanks to a blog post I wrote a couple of years back, I was recently invited on a tour around the new Heathrow Terminal 5 before it opens to the public later this month. More on the tour in a later blog post (also listen to the This Week in London podcast for a walkthrough of the new terminal ).

To get to the British Airways headquarters for the tour on Monday, I had typed the postcode (UB7 0GB) into the Transport for London Journey Planner website and found a set of connections that should have taken me there with plenty of time to spare. It did strike me as a little weird that the headquarters were situated so far from the airport itself (see the same location on Google Maps), but didn't think too much more of it as mt flatmate and I started on our journey to Uxbridge and the end of the London Underground Metropolitan line.

Walking through a residential estate and arriving outside the Uxbridge Royal Mail delivery office, I did start to wonder where the British Airways office was. Named Waterside, it was bound to be next to some water, and of course there was a canal flowing through to lull me into a false sense of security. With desperation growing, we walked into the delivery office to inquire there. As I walked towards the counter it suddenly started dawning on me that BA had perhaps had their mail directed to the delivery office. The Royal Mail guy confirmed this, saying something along the lines of "They do have a PO Box here, yeah. Did you follow your TomTom to get here?".

We were already running later than planned, and it turned out we were miles away from the actual headquarters bordering Heathrow (see map). Luckily we managed to get a taxi and caught the tour group just as they had given up hope on us arriving and were starting to head off.

Postcodes can be a great way of finding a location, with mapping websites and journey planners typically having knowledge of postcode locations across the whole of the UK. That said, how can they be useful considering their sole purpose is not for telling everyday people where something is, but instead for telling a postal delivery worker where to take the mail? How do you know when a postcode is going to relate to a building (often for large users such as businesses, schools, hospitals, etc.), a street (as is often the case), or somewhere completely unexpected such as a postal depot?

Perhaps this is where the user-generated databases of postcodes can start to step in. I've added the postcode UB7 0GB to the New Popular Edition Maps website that allows people to add postcodes they know the location of, as long as they can work out the location from 1940s Ordnance Survey maps. The database of postcode locations is then available to anyone without restriction.