Construction financing over 700k - Is the offer okay?

700k€ loan and only 1800€ installment is ridiculous.

The statement is quite generalized. I would say it depends on various factors here: the age of the borrowers and the interest rate (and thus implicitly on the equity used). Full financing of a 700k house for a 40-year-old couple at 1.4% (annuity = 3.5% -> 36 years term) interest rate is something different than a 30-year-old couple with a 900k property at 1.1% interest (34-year term). In the latter case, the book value must decline significantly more to become a serious problem, and the theoretical term still ends before retirement.

What I find negative (which has basically already been mentioned) is that a fixed interest period of 10 and 20 years in the package does not fit very well together. You can basically do it if, for example, you take 100k at 10 and 500k at 20. Then you might be able to eliminate the 100k in the first 10 years. But in the constellation described here, you are surely running into a refinancing debacle.

Additionally, as teachers you probably won’t make big leaps anymore. An engineer who earns 3.6k net today in his early 30s can double that well in 20 years. Does that also work as a teacher?

And whether the 3.6k net is before or after private health insurance is still open...

That’s exactly why we wanted a threshold of 1800 euros per installment, but with long-term interest rate security.

Briefly about our current situation: We are currently paying around 1500 euros rent including utilities,

Equating warm rent with a mortgage repayment plus ancillary costs for the house is, in my opinion, wrong. At 1800€, you’re roughly at 2200€ monthly costs for the house. We neither know nor are familiar with your living expenses, nor whether, for example, the outdoor areas or various other things were accounted for in the calculation, so whether a good amount for miscellaneous monthly expenses still applies. This typical "we’ll cover that later from ongoing income."

Total loan amount: 700,000
Equity: 55,000*

The first approach, if something might be "tight," is always the question: what does 700,000 cost? Is the house planned very big/too big? Is the land portion so high and unavoidable? In that respect, one can simply say: plan a reasonable house size based on the salary and don’t dwell on what doesn’t match the income.

We want to leave ourselves a buffer in parallel to continue expanding our stock portfolio.

please no fundamental discussions. :)

But questioning where the builder is clinging to should be allowed.

The 700,000 are all tutto completti with - land 100,000 - fully basement house, turnkey 500,000 - 100,000 remaining (earthworks, outdoor facilities, kitchen, etc.) The question is also what the alternative would be: resell the land and scrap the entire project?

The question is also, what the alternative would be: sell the property again and scrap the whole project?

If you plan 160sqm plus basement, then for example omit the basement or 130sqm with basement. :)

The 700,000 are all tutto completti with - Land 100,000 - House fully basemented, turnkey 500,000 - 100,000 remainder (groundwork, outdoor facilities, kitchen, etc.) The question is also, what the alternative would be: sell the land again and scrap the whole project?

I would first try to obtain further financing offers. If you increase the equity share and, for example, could reduce the loan amount to 630-650k and shift another 0.2-0.3% from the interest portion to the repayment portion, it would at least be mathematically "within limits". If possible, you can also consider doing parts only after moving in from ongoing income and in your own work (e.g., outdoor facilities) to save more euros.

The statement is quite general. I would say it depends on various factors: the age of the borrowers and the interest rate (and thus implicitly on the equity used). The full financing of a 700k house for a 40-year-old couple at 1.4% (annuity=3.5% -> 36 years term)

I am always very surprised that many assume they want and can work until the regular retirement age of 67. You might still imagine that at 35 or 40, but I hardly know anyone in their 60s who wants and can do that. Many already go part-time beforehand or retire earlier with reductions. The statement is less general than the statement of wanting to work until 67. That is just as much self-deception as the massive desire to use special repayments and a necessary frugal lifestyle, although everything was squandered on consumption before (I don’t mean anyone specific here).