Siena house numbers import
This page refers to the import of house numbers of the Comune di Siena in Tuscany, Italy. The data used is provided by the Comune di Siena.
Goals
As of August 2026 many addresses in the Comune di Siena are missing in OSM. There are only ca. 2,7k addresses present, while there are about ~19,5k numbers (assigned to property entrances) registered in the database of Comune di Siena.
The goal of the import is to add the missing addresses to the OSM database.
Legal
Data source (as of May 2024): Accessi esterni del comune di Siena
Type of license: Italian Open Data License v2.0
Licence compatibility : compatible
Dedicated upload account: https://www.openstreetmap.org/user/szydzio-imports
The import has been announced on the Italian OSM mailing list.
Dataset
The data is available in KML format and this format will be used for the import.
The KML data (Accesso_Esterno.kml) has the coordinates in WGS84 format for each property entrance (aka accesso esterno) combined with its unique code (cvdiae), number (numero), street name (denominazione), description of street type i.e. Via, Viale, Piazza etc. (dug aka definizione unica di generazione), letter of number (esponente) and street code (codice_strada).
Import process
Basically 5 steps will be made for the import of the data:
- downloading the data
- exctracting coordinates of the housenumbers together with its street/square name, street type and letter of number
- combining the street/square names with its description
- combining the housenumber with its letter (if present),
- importing all the punctual elements of the dataset as nodes into OSM using opendata plug-in.
The first step will be made using Mozilla Firefox, next steps will be made with gedit, Excel and JOSM (using Coloured Streets style & TODO plugin).
Particularly in the third & fourth step, for each point:
- the street name will be changed matching the name of the street currently preexistenting in OSM (including changing from UPPERCASE to sentence case letters e.g. VIA ROMA will be changed to Via Roma) in order not to produce addresses unable to be found later by Nominatim (the house number attached to an existing street nearby should have exactly the same name as the street in addr:street)
- street names will be saved as addr:street and the house numbers as addr:housenumber,
- the letter part of the number (esponente) will also be changed to lowercase (e.g. 30A => 30a) and saved together with the number in addr:housenumber without any separators
After step four the ready *.osm file would be as follows.
In the fifth step an upload of the points as nodes (according to the IT convention) will be executed in bunches of no more than 500 elements in order to carefully cope with the data and revert them easily using JOSM's Reverter plug-in, should something go wrong.
People involved
- data preparing & import process: szydzio via import-account
- local support & consultation: DabMK
Problems and improvements
I expect some problems with the import like e.g.:
- some address may already be present in the OSM database - the data will be filtered with JOSM's validator in order not to produce duplicated numbers with this import,
- if the addresses already present in OSM are not correct (e.g. have a typo in addr:street or missing addr:street) they will be corrected,
- some house number may correspond to a roads/squares or places that are currently missing in OSM - they will be mapped separately (using normal account and/or with the help of local mappers, who offered their support).
QA
After the import possible errors will be checked with Nominatim QA , particularly with the Suspicious addr:street tag layer and OSM Inspector.
Schedule
The changesets will be uploaded starting from mid September 2026 (as annunced in the Italian mailing list).