Evaluation of Construction Project / Credit Offer

Actually, one should recommend that you live for two years as if the house already existed. So always set aside the installment and the additional costs (minus current rent), plus the supposedly abundant surplus. As a nice side effect, equity would accumulate. And you see whether you really want the new lean lifestyle. It's almost a pity that it is supposed to start practically immediately.

Personally, I also have one or two areas where I have to make compromises with the house now or where I know that this simply won’t be possible in the foreseeable future. These are all luxury problems, but I do notice them.

That's correct, the term is theoretically too long for us as well, but in reality, as described, it won't be that long due to inheritance, etc.

Planning for inheritance is generally considered a bad idea.

We have indeed already considered everything, regarding KFW we actually see the new 40+ funding as a must for us, the combination of the higher subsidy with the monthly savings will pay off in the long run, we are very sure about that.

Here, comparing and calculating helps!
"Very sure" sounds like a feeling.

What use are 12k in subsidies if it makes the project 30k more expensive?

It may be true that the difference is small with many prefab house providers, but those are usually already rather expensive.

10 m² less would indeed be worth considering, but this will also depend on which provider we ultimately choose. With prefab house providers, a reduction of the floor plan often does not significantly affect the price as we have found (although an increase certainly does…).

Then just choose a smaller floor plan!

Currently, our offer situation looks as follows (each + 100k € for the plot):

Prefab house manufacturer 1: 186 m² for €407,000 completely calculated as a KFW 40+ house
Prefab house manufacturer 2: 195 m² for €457,000 completely calculated as a KFW 40+ house
Prefab house manufacturer 3: 181 m² for €417,000 completely calculated as a KFW 40+ house (currently still with ground source heat pump and deep drilling here, this might be somewhat cheaper with a different heating choice)

Already €7k-57k over budget.
"Completely calculated"? By you or the providers?

A promising custom-designed offer in solid construction is still pending, we will receive this tomorrow.

What were the main cost drivers for you for this rather high "surcharge" compared to the original house price?

There was no significant driver; it was here and there decisions for something nicer and against sticking to the budget: nicer parquet flooring, more elaborate painting work, more electrical equipment, some carpentry furniture, better bathroom ceramics, subsequent extension of the insulated shell to the attic, more expensive kitchen. And we also simply forgot and underestimated some things despite extensive prior research, especially electrical and sanitary. But that was also a conscious decision to stick with it and not to specify more sparingly.

Maximum 30% of the net income for interest / repayment and additional costs. But I don’t mean the 2% repayment, rather 3-4%. Let’s assume 1.5% interest, 3.5% repayment on 500k, that is €2083 plus additional costs = €2,500. Then you would have to be at €8,300 per month (bonus broken down). At 40% €6,250 net. But that is after children. Including part-time.

Apart from the fact that you never manage to write more than two error-free sentences in your posts: What are you taking that you’re constantly spouting such utter nonsense here? The identical copy and paste rubbish is in every thread. You probably dream of €3,500 net and live in a garden shed.

Apart from the fact that you never manage to write more than two error-free sentences in your posts: What are you on that makes you constantly spout such nonsense here? The exact same copy and paste rubbish is in every thread. You’re probably dreaming of €3500 net and living in a garden shed.

Nope, we have €7,000 net household income with a €1,300 installment and only 13 years left to pay off. All good. We can afford great vacations and consumption for four people. This €1,300 or €800 "surplus" will no longer be enough to vacation well. The belt will be tightened twice as much.

No, we have 7,000€ net household income with a 1,300€ installment and only 13 years left to pay off. All good. The four of us can afford great vacations and consumption. This 1,300 or rather 800€ “surplus” will no longer be enough to keep vacationing luxuriously. The belt will be tightened twice as much.

Didn’t you even have to buy your car on credit?