The WOZ value (Valuation of Immovable Property) is the value of a house or other real estate object determined by the municipality. This value plays an important role in the calculation of taxes, but is also used in rent law, for example when determining the maximum rent via the housing valuation system (WWS).

What is the WOZ value?
The WOZ value indicates what a property would be worth on the free market at a set reference moment, usually 1 January of the previous year. The value is reassessed annually by the municipality in which the property is located.

How does the municipality determine the WOZ value?
The municipality determines the WOZ value using a model-based assessment. This is not done manually for each property individually, but on the basis of an automated system that analyses similar properties in the area.

The following factors come into play:
- Sales prices of similar houses in the neighbourhood (reference properties)
- Area of the house and plot
- Volume of the property
- Year of construction and state of maintenance (if known)
- Situation and location (think of amenities, neighbourhood, view)
- Type of property (terraced, detached, flat, etc.)

The valuer (employed by or on behalf of the municipality) compares your property with several sold properties in the neighbourhood that are similar in type and size. Based on these reference properties, your WOZ value is determined.

Does the valuation differ per municipality?
Basically, the method is standardised nationwide, because all municipalities must comply with the rules of the WOZ Act. The implementation is supervised by the Valuation Chamber, which ensures that municipalities carry out the valuation correctly.

Yet there may be practical differences from one municipality to another:
- Quality of data and measurement data can vary
- Some municipalities work with their own valuers, others outsource it
- The degree of automation and control can vary
- The local housing market obviously varies greatly (think of price developments in urban vs. rural areas)

Although the valuation model is tailored per municipality to the local housing market, the system itself is the same everywhere.

What is the WOZ value used for?
- The WOZ value is important for several purposes:
- Property tax (OZB)
- Income tax (flat-rate home ownership)
- Water board tax
- Inheritance and gift tax
- Maximum rent calculation through the property rating system (WWS)

For rental properties up to and including the middle rental segment, the WOZ value is therefore not only of fiscal importance, but also determines rent regulation.

Can I object to the WOZ value?
Yes, you can lodge an objection with the municipality within six weeks of receiving the WOZ assessment. You do this, for example, if you think the reference properties are not comparable or if there are errors in the data (such as wrong living area). Filing an objection is free, and you do not need to hire a legal advisor, although in complex cases this may be wise.

Conclusion
The WOZ value is an annual estimate of the market value of your home, determined by the municipality based on sales prices of comparable homes and property characteristics. Although the method is standardised by law, there may be minor differences in implementation from one municipality to another. The WOZ value has an impact on both taxation and rent regulation, so it is important that it is determined correctly.