Financing: What interest rate lock? What goes into the budget?

You wrote about paint and floors, so I can’t know that suddenly a buffer is included.

All construction financing calculators only give you a rough guideline. The truth is with the bank. Only those who go there in person (or to an intermediary) will find out what is possible.
Also, the 20% equity quota that is promoted. Nice to have but not mandatory. Assuming good creditworthiness and a good income, it is possible without it.

My source is the internet: ...
80% financing: interest rate 1.9
100% financing: interest rate 2.7
by the way: with all other building loan calculators you can't even select 100%, and with 90% of the credit institutions it says "up to a maximum of 80%", and if you read the forum here the absolute majority will advise you to have 20% as equity
Thought this wouldn't have to be an essay with claim - example - repayment, but well : )

well, consider my headline "rough calculation". then make out of the 40k€ = 20k€ + 20k€ buffer

maybe at the Sparkasse, not at the big banks. A high earner doesn't get a discount there

Well, then what is the forum for? If you argue that you ultimately only get certainty from the bank? Should we answer every question that comes here with "go to the bank?" : ) So let's help each other a bit here with estimates and the internet.

And I’d rather calculate with 10-20k€ too much than too little ; )

Yes exactly, I am also very grateful for the calculation examples. Of course, I also prefer to have more buffer rather than forcing it and then theoretically living like a church mouse afterwards. I don't get anything out of that either. Especially if something goes wrong, etc.

Anyway, many thanks again to everyone for the clear examples and opinions. It helps me.

The problem: spending money or saving it, you can't just easily change this either/or - the attitude towards money (dividing one's money between consumption and retirement provision) is learned as a child and teenager over years with one's allowance. That then manifests itself as a trait.

I can only confirm that. Eating out 7 times less per month also only saves around 300-500€, if you can eat at home for free. Usually, you also have to pay for groceries, energy, pot usage, etc. for the meal at home. Accordingly, your significant cut from 10 restaurant visits/month to 3 restaurant visits only saves 200-400€. To achieve a saving rate beyond 1500€, you then have to cut back significantly on vacations as well. By the way, the renunciation is rather permanent and not only to be seen during the 2-3 year savings phase. After all, something is always being done to the house and garden, even if it is just a new grill or parasol again.

If you really want to realize what you have in mind, I can only agree with the previous speakers: keep a household budget, save for two to three years, build up sensible equity.

However, I also see an alternative: at our bank, financing with little equity is also requested. Such castles in the air (sorry!) as your initial example naturally burst in this case. However, if customers themselves see that the equity is too low (for whatever reasons, it doesn’t have to be just high consumption, sometimes also family tragedies or being relatively fresh out of university), it often helps to scale down a notch. With a (planned) family of four, it would of course be great to have a detached single-family house with a basement, double garage, large garden, etc. However, many customers take the other route: plan smaller. For your data, for example, a 130 sqm mid-terrace house without a basement, with a single garage and a parking space and a small garden. Of course, your equity is also too small for this project (here in the Ruhr area it is certainly feasible with about €250,000). But with a good income, it is still worth examining. The bank would—if the other creditworthiness data are correct—be more willing to do a 100+x financing for such an amount. A condition might then be a high initial repayment rate to get you practically to save backwards and thereby quickly reach a reasonable loan-to-value ratio under 80%. If you then also include an option to change the repayment rate—so you could, for example, reduce the installment yourself for two years during parental leave—that could certainly be an option worth considering if you want to realize the dream of home ownership right now. And if the income rises again after parental leave (or rather “if,” as there are pitfalls in life), you would have paid off the terraced house quickly.