Slowly but doubt about financing

Everything is relative - depending on the point of reference. Do you relate hour 1 to the move-in/start of construction or to the age of the builder?
Related to the age of the builder, the "more equity variant" can certainly look worse.

It's slowly getting more and more complicated

It's slowly getting more and more complicated

I just took your example a bit further.

In assumption 1, the person has a loan of 400K€ at the time of construction with construction costs of 500K€, so 20% equity. In assumption 1, after 5 years, the person has around 350K€ remaining loan with construction costs of 500K€, so 30% equity. In assumption 2, the person has a loan of 390K€ at the time of construction with construction costs of 550K€, so 29% equity.

If you relate assumption 1 to the time of construction, then assumption 2 would be better 29%>20%. If the reference point is the age of the builder, then assumption 1 would be better 30%>29%.

Of course, the value development and the depreciation of the house should also be taken into account.

What I'm getting at is that constructed examples often only support the opinion of the creator and overlook important aspects...

The second point in time is 5 years later. Then calculate the present values for your numbers back to point 1 and compare.
"Assumption" 2% inflation, you can't really argue against that, right?
Let's leave assumptions about wage increases/living costs (keyword inflation) aside.
In what world would we live if only construction costs always increased, but all other conditions remained the same?

But you will admit that I was rather generous with the interest discount for the slightly higher equity and the somewhat lower fixed interest period.
From my point of view, the situation does not improve to such an extent that the years of waiting would be worthwhile.

What I am getting at is that constructed examples often only support the opinion of the creator and ignore important aspects...

What is the saying: "I only trust the statistics that I have falsified myself." Winston Churchill

I am also open to realistic examples that make saving look significantly better, based on the current situation. So not, if one had waited x years during times when interest rates were two-digit... At the present time, expecting a significant interest rate cut is rather utopian.

But you have to admit that I was rather generous with the interest discount for the slightly higher equity and the slightly shorter fixed interest period.

I won’t say anything about that now.. I already did in a previous post...
You can also assume 3.5%, 2.3% or 1.0%... The main thing is that all relevant parameters are assumed and calculated back to the same reference period. Then the model is valid.

I am also open to realistic examples that make saving look significantly better, based on the current situation. So not: you should have waited x years when interest rates were in the double digits...
Expecting a significant interest rate reduction at this point in time is rather utopian.

I would be tempted to say in general that it is "financially" worthwhile if you can reduce the loan-to-value ratio enough to reach the next "interest rate jump"...
And don’t come to me now with "but what if interest rates rise then"...

And who knows, maybe someday the first developer will advertise a 0% financing

And now that’s enough...