Data sources
Every number on this site comes from Polish or EU public statistics — not listing portals.
We aggregate official datasets so foreigners can compare cities without scraping Otodom. Transaction averages lag listing sites by design: they are based on notarial deeds, not asking prices.
Figures refresh automatically via Sidekiq (daily–quarterly per source, plus a weekly full sync). Operators: bin/rails data:refresh — see DATA_OPS.md.
GUS BDL
Statistics Poland — transaction prices, dwelling stock, condo maintenance, social housing rents
Used on: Buying prices, housing stock, cost of owning
NBP BaRN
National Bank quarterly report — transaction PLN/m² for 17 cities (2006–present)
Used on: City headlines, price charts, housing market
Eurostat
EU house price index, rent index, cost overburden, housing deprivation — interactive comparisons
Used on: Poland vs Europe
WIBOR 6M
GPW Benchmark interbank rate — base for variable mortgages
Used on: Mortgage calculator, rates page
OpenStreetMap
Amenity counts per district (metro, schools, parks)
Used on: District pages
data.gov.pl
Catalog of Polish open datasets (permits, land prices, Art 19b developer registers)
Used on: Developer register, open data pages per city, city developer register prices
Live coverage
Expand Data freshness above for sync times and data ranges.