The Open Postcode Finder

Matt WilliamsMilliams

● Aiming to be a sort of 'replacement' of the Royal Mail

Postcode Finder using only open data.● Allows search by postcode or address.● By default only searches OpenStreetMap data.● Will search OS Code-Point® Open if no match is found in

OSM.

Searching

● If you search for a valid postcode you receive a list of all houses with the postcode as well as an inset map showing the area

● If there's no matching OSM houses, you'll just get the map (from OS Code-Point Open)

● Searching by addressworks similarly

● All houses in results list are hyperlinks to an address page

Address Page

● There is an address page for each extracted address from the OSM database showing the address map and postal address

● The street name is a link to all houses on that street

● The postcode is a link to all houses with that postcode

● You can also get a direct link to the relevant object in the OSM database

Technical

● Offline C++ processing tool

– Uses the fantastic Osmium

– Builds up logical street from the disparate nodes, ways and relations

– Also tracks errors.

● A web application for the user interface

– http://milliams.dev.openstreetmap.org/postcodefinder/

– Uses Django, GeoDjango, PostgreSQL and PostGIS

Uses

● Aims to (one day) be a usable product for postcode searches

– Very reliant on OSM data

● Provides a view into the OSM data which is normally hidden

– This encourages people to add postcodes and addresses to OSM

● Has proved handy for merging in external data sources...

Land Registry House Price Data

● The Land Registry are publishing their 'price paid' data sets under the Open Government License

● This includes the price paid for a house (obviously) as well as a full address and postcode

● Using the postcode finder, we match up the entries into:

– Address match, wrong postcode

– Address match, no postcode

– No match

– Perfect match

● Then add the postcodes to the database manually

Progress in OSM UK

c.f. 29 million in PAF; we're now at ~1.1%

2011-03-24 2011-06-24 2011-09-24 2011-12-24 2012-03-24 2012-06-24 2012-09-24 2012-12-24 2013-03-24 2013-06-240

50,000

100,000

150,000

200,000

250,000

300,000

350,000

Houses with post codes

Progress in OSM UK

● But two years ago we were at 0.25% - we've quadrupled

● There's been no real coordinated effort in OSM to add postcodes and addresses to OSM

– There's been a lack of usable data sources

● With the Land Registry data and perhaps soon the Companies House data we can provide mappers with the information they need

● With the right tools and input data, we could increase coverage much more quickly

Thank you