The document describes The Open Postcode Finder, a web application that allows users to search for addresses and postcodes using open data from OpenStreetMap and Ordnance Survey. It summarizes the key features and functionality of the application, including searching by postcode or address, viewing address pages with location maps, and technical details about how it was built using open source tools. It also discusses how the application can encourage more complete address data in OpenStreetMap and how additional public datasets could help further improve coverage.

1. The Open Postcode Finder
Matt Williams
Milliams

4. ● 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.

5. 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 address
works similarly
● All houses in results
list are hyperlinks to
an address page

6. 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

9. 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/postcodefin
der/
– Uses Django, GeoDjango, PostgreSQL and
PostGIS

10. 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...

11. 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

13. 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 2013-06-24
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
Houses with post codes

14. 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

15. Thank you