Construction costs for property tax calculation - What must be specified?

Hello.

To determine the assessed value, the tax office wants to know some things, e.g. the construction costs.
What is to be stated here? These can be extremely different, for example, my neighbor could build the same house as me, only completely by himself. Both houses would be worth the same, but construction costs would be significantly different...
How is this actually checked?

Furthermore: calculation of floor area – in the building plan, e.g. plaster is not taken into account here. Can a flat percentage be deducted?

Thank you.

ha cool that you ask the question, I still have the form here and don’t know what to fill in. Just the house, right, without the garage? And without the kitchen and stuff – but with the interior finishing including painting work?

I honestly listed the individual items. They should pick what belongs and simply leave out what does not belong.

I left out kitchen, furniture, [Außenanlagen]. I think also painting work, floors...

Furthermore: floor area calculation - for example, plaster is not taken into account in the building plan here. Can you deduct a flat percentage for that?

I haven't even thought of that.... I think that goes too far?!

DIN 277 does not allow a deduction of 3% for plaster; the plaster is included in the construction base area and therefore must not be deducted again from the net floor area.

I would have taken the number from the building permit, that is a standard value multiplied by the enclosed space.