Please note: The algorithm descriptions in English have been automatically translated. Errors may have been introduced in this process. For the original descriptions, go to the Dutch version of the Algorithm Register.
WOZ valuation models
- Publication category
- Impactful algorithms
- Impact assessment
- Field not filled in.
- Status
- In use
General information
Theme
Begin date
Contact information
Responsible use
Goal and impact
Purpose: The purpose of the algorithms used is to calculate the market value of immovable property within the framework of the WOZ Act.
Impact: The level of the WOZ value has various implications for stakeholders (citizens and businesses). The most significant impact relates to direct taxes, such as property tax. In addition, the WOZ value has a direct or indirect influence on other taxes, such as inheritance and gift tax, income tax and corporation tax.
Considerations
The use of valuation models is crucial for calculating the WOZ value efficiently, accurately and consistently. Without these models, it is not possible to do this on a large scale.
Human intervention
The WOZ value is formally determined by the tax officer (Section 22 of the WOZ Act). In practice, however, the WOZ value is determined by the WOZ valuer. The model’s outputs are checked by valuers through random sampling and comprehensive checks using standardised, established procedures. Valuers also set the model’s parameters.
AI Act Art. 14 (human oversight): The system operates on a ‘human-in-the-loop’ basis: WOZ valuers monitor the model’s outputs and validate them through spot checks and comprehensive reviews. The tax officer formally determines the WOZ value; the model merely provides a calculated basis.
Risk management
Legal basis
The WOZ Act (Act on the Valuation of Immovable Property).
Links to legal bases
Operations
Data
WOZ property details (usable floor area, year of construction, location, quality, maintenance) and sale prices of comparable properties.
Technical design
Key2Waarderen uses a model-based comparison method (not machine learning).
Input: characteristics of the property to be valued (usable floor area, year of construction, location, quality, maintenance) set by valuers.
Operation: the value of the main building is determined by comparison with the main buildings at reference points; the value of the land and other components is determined using model parameters.
Output: the calculated market value as the basis for the WOZ decision.
Valuers check the results through random sampling and comprehensive checks in accordance with standardised procedures.
External provider
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