Poland's Article 19b developer register exists for one reason: to stop buyers from being fooled about how much an apartment "really" costs. Since 2024, every developer has been legally required to publish, unit by unit, the price history of everything they're selling — the idea being that if a "special offer" price is quietly 20% above what the same unit cost three months ago, everyone can see it.
Pulling the latest register snapshots city by city, the pattern isn't subtle. In the past few weeks alone, at least eleven Polish cities have logged developer price jumps that have nothing to do with inflation, construction costs, or the market — and several of them look exactly like the loophole-gaming the law was written to kill.
The worst offenders
Szczecin takes the prize. Idea – Inwest listed a unit at 8,640 PLN/m² and then reissued it at 31,000 PLN/m² — a 259% jump on paper — with four more units from the same developer up between 54% and 213%. For context, Szczecin's actual secondary-market median sits at 9,378 PLN/m². The "new" asking price on that one unit is more than three times what anyone in the city is actually paying for a flat.
Białystok isn't far behind. DOT Sp. z o.o. pushed five units from 6,788 PLN/m² to over 19,500–20,500 PLN/m² — a 187–202% spike — against a city median of 9,164 PLN/m².
Łódź: Liberty Jaracza more than doubled five units, from roughly 8,200–8,550 PLN/m² up to 16,900–17,900 PLN/m² (up to +118%), while the city's actual median sits at 7,971 PLN/m².
Gdańsk: Olchowa Invest logged five units jumping 93–106%, one going from 8,831 to 18,144 PLN/m².
Lublin, Zielona Góra, Rzeszów and Gdynia all show smaller but still eyebrow-raising moves — 20% to 62% "price increases" on individual units within the same building, filed within days of each other.
Why this happens
None of this means construction costs doubled overnight. The register logs listed prices, and a common tactic is to post an absurd new baseline right before a "limited-time discount," so the discounted price still nets the developer more than before — while technically complying with the disclosure law. Other times a unit gets re-listed after being pulled from the market for months, and the "old" price in the register is simply stale.
Either way, the register is doing exactly what it's supposed to do: making it visible. The question is whether anyone acts on it. For now, the burden is on buyers to actually check a unit's price history before signing — something almost nobody outside a handful of housing-data nerds currently does.
The other number moving this week: your mortgage
While developers were busy repricing units on paper, the number that actually determines what buyers pay each month kept drifting the right direction. WIBOR 6M was fixed at 3.84% on August 3, putting the estimated mortgage rate around 5.84% (with a typical ~2pp bank margin) — continuing a slow cooling from the rate environment of the past two years. It's not dramatic, but paired with flat-to-falling secondary market prices in cities like Łódź (-0.83% q/q), Białystok (-2.22% q/q) and Olsztyn (city median -11% in the latest register snapshot), it's the first time in a while the macro backdrop has quietly favored buyers — even as some developers try to write themselves a better headline number.
The takeaway
If you're shopping new-build listings anywhere in Poland right now, the single most useful thing you can do before making an offer is pull the unit's Art. 19b price history — not just trust the "sale price" on the portal. The register was built precisely so you could catch a move like Szczecin's 259% or Białystok's 202% before it costs you real money. This week's data says: check it.
Figures drawn from Art. 19b developer register snapshots (data through Aug–Sep 2026) and NBP BaRN secondary-market pricing (2026-Q1) via Bankier.pl for WIBOR.