Feasibility of a DIY house using timber frame construction

Does the type of property matter here (e.g.: orchard meadow)?

Regards

Yes.

That is called building land. Preferably with a development plan or in the inner area according to §34.
Better forget about the outer area.

Without infrastructure, no tiny house either.

So if it is not building land, for example, the option remains to register a "organic farm with dog breeding" and try it that way.

Just registering is not enough. You have to actually implement it.
If I remember correctly, the whole thing must also exceed a minimum size.
If it is an outdoor area, then forget it.

As far as I know, you are not even allowed to build a permanent shelter for your planned chickens outdoors. Perhaps a mobile chicken coop would be worth considering, and for the 100,000€ a high-quality camper. But even a garden shed for work tools is not permitted outdoors.

For a secondary agricultural business, you would also have to generate some income, which will be very difficult on 1000 m².. otherwise, it would again "just" be considered a hobby.