Mini house - possible for 300K €?

Smaller houses with 70-90 m² of living space are always available on the market. There isn’t much competition either, because they are not really of interest for couples and families. I wouldn’t build something like that new, as it is uneconomical. Too little demand, therefore no prospect of sufficient increase in value.

You can find such house sizes in old (worker) settlements. They are very common here in the Ruhr area, for example. Usually lots of greenery around and partly the entire settlement is listed as a historic monument. Very quaint and cozy. I don't know how it looks like in your area in Lower Saxony or in your surroundings.

I would also lean more towards a permanent campsite with a lease. There are small mobile homes or similar. Suitable as a primary residence with the necessary infrastructure. Usually also nice there. Otherwise, as mentioned, buy existing property.

That's right, there is also a small stock here, with some really cute little houses. The question is what you are interested in, you can also cultivate a garden with lease etc.

Such house sizes can be found in the stock in old (worker) settlements. They are very common here in the Ruhr area, for example.

I actually already looked at such a house! €145K for a "well-maintained original condition" from the 60s with 63 sqm. No parking spaces, no driveway. I had my work colleague with me, who strongly advised against it (he lives in his fourth property). It was basically a shell, everything would have had to be done – electrical, heating, windows, bathrooms, insulation. The idea is great but these houses are completely overvalued here. Whether you can sell it again in about 10 years without much loss is really the question.

But everything new might have been possible for 150k€ and you would have been at your desired total of 300k€.