Retrofit warm and cold water meters?

Hello everyone!
We are currently building a house with separate living and practice units.
Now and for the coming years, we do not need separate water meters for the 2 units. Maybe later, if one day we retire and rent out the 2nd unit, possibly even earlier.
Because life is unpredictable, and right now - like everyone in this phase - we have increasing expenses, we do not want to spend money now for a possible case that might occur in 20 years.

We got an offer from the plumbing company just for the "Vorrichtung" for water/heat meters: €2220, which we would prefer to spend elsewhere.
Does anyone know if this Vorrichtung is already necessary now, or if installing the meters later - without Vorrichtung - would otherwise be especially expensive/complicated?
Thank you very much in advance!

No, you don’t need that. You can have water meters for cold and hot water as well as heat meters "cut in" later.

No, you don’t need that. You can have water meters simply "inserted" later for cold and warm water as well as heat meters.

That sums it up perfectly! And just as an aside, for 2K you get plenty of meter pre-installations!!!!!

We are currently building a house with separate living and practice units.

What is currently happening with the practice unit? Used by yourself as a practice? Does it not also make sense to separate the costs there?

Thank you, that makes the decision much easier for us
Yes, the practice is used by us, we write off the costs as a flat rate. Currently, we are satisfied with the solution

Thank you all, that makes the decision much easier for us
Yes, we use the practice, we deduct the costs as a flat rate. Currently, we are satisfied with the solution

provided the tax office accepts it. Later, you can claim the installation costs