What costs will we incur?

Hello everyone,

I or rather we need opinions from people who know more than we do :-)

Here is what we are planning:

My girlfriend and I want to build a detached house (solid house) at least Kfw 70 without a basement with about 140-150 sqm of living space, with as little or no personal contribution as possible.

We are getting a plot of land from my father-in-law. However, it is still a meadow or pasture. I cannot estimate what costs will arise from that. In my opinion, no real estate transfer tax should apply because it is a gift. So the only things I can think of are the notary and all connection costs. Unfortunately, I have no idea how much.

We imagined the price roughly around €200,000-220,000 for the house plus the development costs for the plot.

Additionally, costs for outdoor facilities and kitchen will arise. That will probably be another €20,000 or more.

So I come to the following total costs
Solid house 140-150 sqm 220,000
Outdoor facilities and kitchen 20,000
Development costs 30,000
(Amateur estimate)
Total 270,000

€270,000 seems to me personally extremely much, since we already have a plot. So where is the mistake? Is there even one?

It should be said that we live in Lower Saxony in the countryside and therefore no prices like in Hamburg or Munich are to be expected.

Looking forward to some feedback. If you need more information, feel free to ask :)

Thanks for your answers!

Is the plot even designated as a building area? To what extent is the plot already developed? What about the remaining ancillary building costs, or are they included in the development costs?