Land purchase of 319 sqm for 191,000 euros and house construction realistic?

If you take your time properly or are satisfied with Q2, no. If a layman wants to produce Q3 and finish in a finite amount of time, good luck.

I puttied and sanded 40m² of living room concrete ceiling. Result is so-so, but I will never put myself through that torture again.

Although Q2 is usually sufficient for the ceiling + painter’s fleece. And yes, ceiling is a bitch...

You and your painter's fleece again. Painter's fleece does not magically turn a scratched Q2 into a Q4, not even into a Q3. What you see in Q2 as scratches without fleece, you also see with fleece. Moreover... it can't be emphasized enough... especially for a layperson in EL, it is an enormous effort to wallpaper a single-family house with easily 400-500m² with painter's fleece. I more or less went through it alone with the help of a craftsman friend and took several weeks for sanding, filling, sanding, priming, painting 1-2 times (ceiling 2x, colored walls 1x white, 1x color, white walls 1x white). The intermediate step with painter's fleece would have taken another 3 weeks for sure... people tend to forget that you don't do this daily and therefore need longer than the painter. The few cracks that the fleece bridges. Put Knauf Uniflott on, paint, done. Sure, if you have all the time in the world. But who has that shortly before moving in with a new build...

Regarding the personal work, I know it won't be a walk in the park. However, we completely finished 100 sqm of the attic in my father's house. Completely. Built additional walls, installed drywall partitions. Did roof insulation with a vapor barrier. Suspended the ceiling and fully covered everything with Fermacell panels. Chiseled slots and laid electrical wiring. Spackled and sanded everything. Laid the insulation mats for the underfloor heating and installed the pipes. The screed and plastering of the walls were then contracted out. Tiles and floors were done by ourselves again. So yes, a house is a lot of work and will take at least a year. The plot is exactly between the workplace and home. Therefore, perfect to still get some work done after work.

Our luck is that our apartment belongs to my wife's parents. The rent goes to the family. So regarding double financial burden, this is an advantage.

About the construction road and fence etc. Isn’t my picture in the attachment visible? The plot is surrounded by roads on two sides. I don’t need much fence. On the property boundary to the other semi-detached house, I can share it with the neighbor. There is already a fence on the front side because there is already a house there. Maybe I need 20-25 m of fence or I won’t build any at all if I don’t have to.

We have no problem if the gravel stays in front of the house for 5 years or if only minimal work is done.

But basically, I think it would be good if I bite the bullet in 2024 and 2025 and save properly so that I come up to a financing amount of around 400,000. Then everything will have more leeway. If the interest rates don’t rise etc.

I more or less went through it alone with the help of a buddy from the trades and took several weeks for sanding, filling, sanding, priming, painting 1-2 times (ceiling 2x, colored walls 1x white, 1x color, white walls 1x white). The intermediate step of painting fleece would have certainly taken another 3 weeks... you easily forget that you don’t do this daily and therefore take longer than a painter.

Uh – two left hands or the wrong tools? By the way, painting fleece is not comparable to wallpapering.

A few things caught my attention in the cost breakdown. But first, the question is what the plan is regarding the house construction. Freely planned and then executed with a general contractor, or a prefabricated house from the catalog?

What I would no longer do without is construction legal protection insurance and the accompaniment of the construction project by a publicly appointed and sworn expert. Especially the latter will definitely be costly but has an incalculable added value at the end of the day and you have a second party liable should there be major defects in the house in the end. Because the expert is also liable through their activities.

Regarding the own work, I know it's not going to be a walk in the park. But we completely renovated 100 sqm of the attic in my father's house. Completely. Built additional walls, installed drywall walls. Did roof insulation with a vapor barrier. Lowered the ceiling and fully covered everything with Fermacell boards. Chiselled slots and laid electrical wiring. Spackled and sanded everything. Laid the insulation mats for the underfloor heating and installed the pipes. The screed and plastering of walls were then contracted out. Tiles and floors were done by ourselves again. So yes, a house is a lot of work and will take at least a year. The plot is exactly between the workplace and home. Therefore, perfect to do some work after work.

Our luck is that our apartment belongs to my wife's parents. The rent goes to the family. So regarding double burden, it's an advantage.

About construction road and fence etc. Isn't my picture in the attachment visible? The plot is surrounded by roads on two sides. I don't need much fence. I can share it with the neighbor on the boundary of the other semi-detached house. There is already a fence on the front side because there is already a house there. Maybe I need 20-25 m of fence or I might not build any at all if I don't have to.

We have no problem if the gravel lies in front of the house for 5 years or if only minimal work is done.

But basically, I think it would be good if I bite the bullet in 2024 and 2025 and save properly so that I come up to a financing amount of about 400,000. Then everything has more breathing room. If the interest rates do not rise etc.

I assume you have craftsmen in the family/environment who made the work in the attic possible for free or for a few bucks. Otherwise, what you described (especially the electrical work) is not doable. If you can recruit a few people for that – great. Otherwise, I assume that in a new build, all safety-relevant work (i.e. electrical, water pipes, heating pipes etc.) must officially be done by a professional. The bank will most likely want to ensure that the value of the house remains stable. That won't work without invoices for all the critical work. No uninsured fire (electrics) or water damage (pipes) will be risked there. That would be my assumption at least.