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WOZ is the Dutch abbreviation for Valuation of and is derived from the Valuation of Immovable Property Act. This Act regulates the valuation method.

How does the RBG determine the WOZ value?

Which characteristics determine the WOZ value?

To determine the WOZ value, we look at:

  • the date on which we determine the WOZ value
  • the characteristics (such as the type, size, construction year, cadastral area and annexes)
  • the market value
  • the market data

What date do we use to determine the WOZ value?

For the tax year 2024, we will use the value on 1 January 2023. This a national scheme. We also consider the situation of the office building on 1 January of the current tax year (2024).

The characteristics

The characteristics of immovable property also determine the sum of the WOZ value. We retrieve the characteristics from construction plans, photos and/or recordings of the immovable property.
For non-residential property, it concerns the following characteristics:

  • the type (e.g. office,warehouse, workshop)
  • the size
  • the construction year
  • the location
  • the state of repair 

The size

RBG uses gross dimensions (surface area) to determine the WOZ value of non-residential properties for the Municipalities of Delft, Schiedam and Vlaardingen. The gross surface area has been described in the Dutch NEN 2580 standard.

The market value

RBG redetermines the WOZ value of your office building or piece of land every year. We determine the economic value; the price the highest bidder would pay if the office building or piece of land would be for sale in the most suitable manner and after the best possible preparation.     

The market data

During the assessment, RBG uses a range of different data.  We collect, record and analyse the market data constantly. Market data are asking prices, sales price and rental figures of office buildings.

How do we determine the WOZ value non-residential properties?

Marketable non-residential properties

are shops, catering establishments, offices and commercial space. By ‘marketable’, we mean that the property has a good market position. If sold, it will generally sell quickly. Marketable non-residential properties are valued using . With this method, the value is determined by multiplying the rental value of the property by a .

  • is determined by multiplying the surface area of the property by the rental price per m2 per year.
  • The capitalisation factor is derived from available market data. The appraised selling price is used for this purpose. The valuation is based on comparable properties that have been sold around the reference date. Then this selling price is divided by the rental value. This yields the capitalisation factor.

We continuously collect, record and analyse market data. Market data consists of sales prices, rental figures and asking prices of commercial properties.

Unmarketable non-residential properties

Unmarketable is defined as immovable properties that almost never sold, such as schools, sports centres, hospitals, homes for the elderly, etc. We determine the values of unmarketable non-residential premises using ‘the depreciated replacement cost’. The depreciated replacement cost is the sum that would be required if the object was to be rebuilt. The depreciated replacement cost is the replacement cost that takes the purpose of the object and the technical and functional ageing into account.

What is a Valuation of Immovable Property assessment?

You will receive the WOZ value as a WOZ assessment. This WOZ assessment is usually stated on the assessment form. All owners and users will receive a WOZ assessment. Owners are those who are registered with the Cadastre as owner or holder of limited real rights on 1 January (long lease, buildings rights, usufruct, use and habitation or apartment right).

The conditions for the WOZ assessment are:

  • The WOZ value is applicable for one tax year
  • You will receive the WOZ assessment at the start of every year
  • The WOZ value will be redetermined every year

How can I gain access to the property valuation notice?

Did you receive an assessment with a WOZ value (WOZ assessment in your name? Then it is possible to access the property valuation notice via Mijn RBG. You can log into Mijn RBG using eHerkenning.

Do you object to the WOZ value?

You can make a telephone appointment with one of our assessors. You can set a date and time in our agenda. The assessor will call you. Together with you, they will determine whether or not a mistake has been made and making an official objection will not be necessary. Often, objecting will not be necessary.

Do you still object against the WOZ value or the explanation after talking to the assessor?
If you (still) decide to object, then you can object free of charge within 6 weeks after the date on the WOZ assessment via Mijn RBG.

Can I ask an agency to object on my behalf?
Yes, but you will almost never require an agency to object. We will take every objection seriously regardless of whether they have been submitted by an agency or you. If we made a mistake, then we will naturally correct it. Free of charge, of course.