Etterbeck Cadastrial

The cadastral income value for individual properties appears to be an almost complete lottery as it seems to depend on when the valuation was done and what the market was like at that precise time.

The federal authorities are responsible for setting the values, and subsequently re-evaluating them, but receive no benefit from the result as the relevant tax all ends up further down the devolved chain and consequently show little interest in putting the values right.

If you are looking to buy then the notaris who is handling the sale should be able to tell you. If you are renting the tax should be paid by the owner.
Once you find the actual value, you still need to know the %age rate applied by the commune to know how much you will actually pay and that rate varies - upwards! - each year.

It's based on more than size state or repair of the building, method of heating, number of toilets all sorts oh quirky stuff. So an apartment that needs some work may well have a lower one, but if the previous owners did it up and didn't register it then atht can also be low. If looking to buy up I can ask the vendors for a ball park figure

You have to go here (or phone or email):
Algemene Administratie van de Patrimoniumdocumentatie
OW-Antenne Mutaties
Antenne Mutaties 213 Brussel
Kruidtuinlaan 50 Bus 396
1000 Brussel
Telefoon : 0257/55220 ( 9 tot 12 uur )
Fax : 0257/96860
E-mail : meow.antenne.213@minfin.fed.be
Openingsuren : Telkens tussen 9u en 12u en van 12u tot 17u na afspraak