The first data source was the Kazan Housing Fund
, providing сonstruction and operation dates of about 5.000 buildings. If there was no construction year, the building was assigned with the operation year. As the data covered only 5.000 out of 75.000 OSM objects, it was necessary to look for other data sources.
The cadastral building passports could be another data source, as they often contain years of construction. The public cadastral map
showed that the construction year is indicated for most of the buildings. Thus, using the Rossreestr API
requests, we received a table with 155.000 rows. It is important to remember that cadastral objects do not always refer to the whole building and can describe different parts of the same building or an area with several buildings. After filtering the data and leaving only those buildings with an address, year of construction, and fully completed buildings, only 95.000 objects remained. This data source also provided object names, while construction and operations years were used similarly to the Housing Fund (when there was no construction year, the building was assigned with its operation year).The Ministry of Culture
's open data shared information about cultural heritage objects. These objects are usually the most attractive to check on a map. A total of 551 objects with construction dates were extracted for Kazan (not only buildings but also monuments, streets, etc.). The objects also kept names and addresses for further processing.
All the data did not have a spatial reference; consequently, it needed to be geocoded to be shown on the map.