Financing check - realistic or nonsense?

The coolest thing about the whole farce is still the dog breeding operated off the books.
Does the development plan even allow for that?
Things like dog hotels / breeding are only rarely approved anywhere.
Usually, these are plots under highway bridges, where you wonder passing by why there is even a house there.
And 10k income but not being able to pay taxes.... sorry, but that makes me choke back a laugh a bit.

I am grateful for factual feedback, but this is unnecessary. The dog breeding is not operated off the books, but is a hobby without profit intention. This has been clarified and documented in writing with the tax office. Due to the lack of profit intention, there is no business, so it is also not relevant under building law. I would therefore be grateful if you refrained from such insinuations.
Moreover, this "farce," as mentioned at the beginning, only serves to get an idea of what we can afford and what not. I am totally fine with planning one or two sizes smaller here. Thank you.

Sorry, but if 10k remain per year, even if it was not intended at all, they must be taxed. I don’t know what your tax officer is smoking, but may he stay with you for a long time.

The consultant just enters a few values into the form. He can't give you the actual costs for your project either. He wants to sell you a loan. And in my opinion, you will definitely encounter difficulties there because you do not have an attractive location and high costs.

Yes, there is a green light if the household income fits, the equity, and the project. But you (together) simply have below-average income. Two normal DINKs average about €4100. That is the classification. And you want to manage alone what almost always requires two nowadays. To realize the dream of a home, your wife almost certainly has to contribute.

Realistically, you might get a loan of about €380,000. So you have a project framework of €540,000 with equity. For house, land, and incidental construction costs. Find yourself a better plot, smaller & flat. Then look at a solid house, 130-140m². Simpler standard, not KfW40+. So (hopefully) €2250*140€/m2 -> €315,000. €50,000 land. Then 20% incidental construction costs on both. You are at €437,000. Then comes kitchen, land, and garage. And you are already quite close to your absolute limit.

what do you think of the idea? Because we are going with the budget like that!

What is your current savings rate, without any pretense? If you include unplanned, irregular monthly payments.

It should be relatively easy to calculate with a salary/account over 6 months with the real expenses/account debits.

Because I’d say you know €1400 warm. But €1400 rate + €400 monthly additional costs, not.

Broker land
2,970.00 €
Notary
1,980.00 €
GrEwSt
4,752.00 €

These are incidental purchase costs

Public development
0.00 € - land is developed
Private development
1000 € per meter of conduit, distance street to technical room is 4m, I calculated 5,000€ here

I would budget 10,000. More or less it’s about right.

0.00 € - included in house price (prefabricated house) with dri

Construction contract review: who actually reviews what?
Everything the prefabricated house company AI offers you is not for you, but they work for the company.
If you have something reviewed or insured, or consult an expert, then he works for you. Cost around 3-5 thousand.

Excavation
2,500.00 € - 500m3 at 5€/m3
Removal
3,000.00 € - 250m3 at 12€/m

These are flat rates the prefabricated house company keeps ready for everyone. If your plot is different, more difficult, then additional costs occur. Often in the five-digit range. For a slope easily double that.
Removal: does that also mean disposal? Are you sure removal is included? Standard keeps storage on the plot.

We discussed this with an Interhyp advisor, from his point of view it wasn’t a problem as long as the total household net income is right. Do you have other information on that?

But he is not a construction expert! He blindly takes your figures. You buy the land because he gives the green light, the finance bank wants the house calculation, gets yours, corrects some costs upward, garden downwards, and then you sit without money in a year because so many costs simply weren’t included.
Earthworks on a slope can also easily cost 40,000€. The standard from the company only provides 2,500...
No idea which company AI offers you, and then the sqm living area for a bargain - what about sanding and painting work, what about floor coverings? Upgrades to the offered standard? Bathroom fixtures? Sockets, outdoor lighting? Carport? Where is the buffer that usually evaporates already in the shell construction? Double paneling for the kitchen wall cabinets? Satellite system? And and and?
But it’s all in the forum anyway :)
I also don’t like Apokolops’ statement. Nevertheless, I know myself that anything over about 4,000€ additionally earned through hobbies has to be reported to the tax office. Just this hint here off topic, without wanting to make it a subject.
And you have to be able to afford a hobby. Nowadays it is a luxury not to go to work because of pursuing a hobby.
Let me put it this way: if your wife does not generate an imputable income, there is no house. That is the price of not working.
In my environment, such a thing hardly exists anymore - even mothers work again and help with household income.
And:
You don’t build a granny flat, KfW40, and sqm for free, nor do you make profits or get gifts or anything: you spend three times as much cash!

Saldo30

More info is actually not needed!

Sorry, but if 10k remain at the end of the year, even if it was not intended that way, they have to be taxed. I don't know what your tax officer is smoking, but may he stay with you for a long time.

It's called "hobby loss". There are supposedly some clever people who start a business primarily to generate a loss over the long term, which in turn "reduces" their own income or that of their spouse. After a few years, you are usually "cut off". Just a little tip for the OP (without wanting to imply anything): It doesn't apply "out of sight, out of mind"; if the business actually generates a profit rather than a loss contrary to the statements, previous years can also be adjusted retroactively for quite a long time. Such things almost always come to light eventually, especially in dog breeding. ( was faster)