WOZ value: the municipal valuation (2026)
The WOZ value (WOZ-waarde) is the value your municipality assigns to your property each year under the Wet waardering onroerende zaken. It's the basis for several taxes: the OZB property tax, the eigenwoningforfait, and part of the water-board levy. The value reflects what the home was worth on 1 January of the previous year, and you can formally object (bezwaar) if you think it's too high.
What the WOZ value drives
Three things scale with your WOZ: the OZB (a small percentage of it), the eigenwoningforfait (0.35% of it added to your income), and the owner part of the water-board and sewerage charges. A higher WOZ therefore means slightly higher yearly costs — the calculator ties OZB and the forfait to it via a WOZ-to-value ratio you can adjust.
How it's set and challenged
Each municipality determines the WOZ using recent sale prices of comparable homes, referenced to 1 January of the prior year. You receive a WOZ decision (beschikking) early in the year. If it looks too high (or too low, which matters when selling), you can file a bezwaar within six weeks — free to do yourself.