What house construction options are available under these conditions?

We will definitely hear/read from each other again during the argument ;-p

What do you mean by that?

How many rooms do you have?

3.5 – so one is "free," currently used as a workspace for home office & dining room

We will probably have to reconsider staying there for now and possibly optimizing the space. My wife will be happy to walk up to the attic while heavily pregnant Thanks again for all the advice!

My wife will be happy to walk up to the attic heavily pregnant Thanks again for all the advice!

I am too... it does get really exhausting at some point (especially when you have asthma plus hay fever...) but it passes and you don’t necessarily have to do it several times a day in the end. I found it more exhausting right after the birth having to go up there with the baby in the MaxiCosi

Oh, then you don’t have any stress after all. 70m2 and one room free, that’s more than enough for three people. I would also save up, look around, and then strike. Sure, with a belly/baby/toddler there are better options than the attic, but with that rent price...

Also consider the expense calculation unrealistic. If it were correct, you would have to save nearly €50k every year, where has that gone? Take a closer look here as well. I would also not exclude having pets; being pregnant and carrying a Maxi-Cosi upstairs is really a last resort. Regarding the 'toddler doesn't need space' comments: The child doesn't need it, but the parents do! For example, to be able to sleep peacefully or do other things, to have places to retreat.

How do you mean that?

You are putting unnecessary pressure on yourself without reason. It’s like the clowns writing here ... "My landlord has terminated my lease for personal use, now I have to find a plot and put up a prefab house within 12 months"... Building or buying a house is not something that should happen under time pressure, otherwise wrong decisions will be made. No offense meant but... You can’t even give a qualified estimate of what the project should cost you, while you yourself write that you have been a silent reader for a long time.

Wow, what’s coming up again, it makes you lose the desire for owning a home and/or building

Then I’ll build a fantasy house now, okay?
Plot 500sqm * 300€ + additional costs = 160k€
House 170sqm * 2000€ = 340k€
Large garage OR basement = 40k / 60k ~ 50k
Additional construction costs + ceiling + floors + buffer + exterior = 40 + 15 + 15 + 20 + 20 = 110k€
Total = 660k€
To be financed 610k€

The effort is commendable, but what’s the added value? Where is the house supposed to be built anyway, wouldn’t it be more interesting or sensible to ask that first, in order to then – if necessary with an inquiry about the land costs there – build the fantasy house?

Take a look on the usual portals what existing properties in your desired size and features cost in your region. Then you already have a rough cost framework.

That’s how it’s done, that makes more sense, at least rather than calculating with 600,000 euros which don’t fit the OP at all, or which he doesn’t want or need anyway.!

I see the little equity critically. It’s a 100% financing since you won’t get additional costs and kitchen financed from the bank. If you calculate like the colleague above, you end up with approx. 600,000 € loan amount.

No, you don’t have to end up at that sum and if then no realtor is involved, the total costs are lower and the kitchen doesn’t cost 15,000 euros, then the equity is at least sufficient

We would like to stay around 400k +/- ~10%

Exactly, and that can absolutely be realistic

Regarding the ‘toddler doesn’t need space’ comments:
The child doesn’t need it, but the parents do! For example, to be able to sleep in peace or do other things, to have retreats.

Everyone should do as they think best, but basically it’s nicer if the child – even a toddler – has their own room. Also, it was always important to me that my two boys learn to walk on their own plot, grow up on their own plot and if you can afford and choose it and want to acquire property, then you should do it early enough.

Questions that arise before I build a fantasy house (some of which have already been asked). Here again briefly noted why not ask for more important things first before (no offense) just throwing one out here?

1) In which city/region is it supposed to be built? Regarding state funding, the choice of regional banks and especially building a fantasy house, everything can be assessed and evaluated much better.
2) What financial burden regarding interest and repayment rate are you putting on yourself?
3) Do the parents already own property?
4) Are own contributions possible? Is there a circle of friends or acquaintances for that?
5) Is part of the current equity possibly in a building savings contract?
6) Employer loan possible?