Uncertain due to financing

First of all, thank you for the opinions so far.

The question is whether it will be sold with residual debt. That is the risk factor. Making a good income means about €4500 net in our case. A 4% repayment rate is too much for me. I definitely don't want the financing to be just barely fitting and then have to turn over every euro. If that, in turn, means we can't afford it, that would be a pity, but it can't be changed.
The model was developed with a financial advisor and from his perspective is a feasible approach and from his perspective not so uncommon. I'm just not 100% convinced yet...

I don't quite understand what the "model" is supposed to be...

If you pay little, high debts remain. In a future sale, the debts must be paid off, the small remainder goes to you. And from this remainder, you want to buy a condominium? I don't believe that works.

I wouldn't believe in planned increases in property and land value.

1% repayment is an absolute no-go.

For you and currently for two reasons.

1) Historically low interest rates. Your plan can already be over in 10 years. Namely when interest rates have risen by then.

2) Your age. No reputable bank will go along with this plan. And your financial broker should be tarred and feathered.

In the end, people complain about the bank that goes along with it, following the motto: But we should have been told that back then.

There are even now the first banks that generally exclude 1% repayment.

The statement contradicts itself. You are 40, have 40 in equity, a purchase price of 360k, earn quite well, and want to repay a maximum of 1%. Sorry, at this interest rate level, that is foolish. If I were you, I would look for a bank that offers a 20-year fixed interest rate as a full repayment borrower (it exists). After 20 years without special repayments, you are done.

Maybe you should ask yourselves why you want to buy a house. You are planning a mixed thing between personal use and investment property, but in principle you are not taking advantage of either of the two benefits that building a house brings. As you are planning now, you might end up breaking even, or possibly making a profit of 10,000 ~ 20,000 euros. (compared to renting an apartment for 20 years, a very meager savings rate) You have to be aware of the fact that a house loses about 1/3 of its value immediately after handing over the keys, plus countless additional construction costs that a subsequent buyer does not pay. In your model, you are tenants in your own house and at the end you sell it with a backlog of renovations. You should decide: rental apartment and "living," or building a house and living for the house; that is not to say that one cannot live with a house, but a lot of capital does flow into its maintenance.

Maybe you should ask yourself why you want to buy a house. You are planning a mixed thing between owner-occupancy and an investment property, but basically you are not using either of the advantages that building a house brings. As you are planning now, you might end up breaking even, or possibly making 10,000 ~ 20,000 euros profit. (compared to renting an apartment for 20 years, a very meager savings rate) You have to be aware of the fact that a house loses about 1/3 of its value immediately after handover of the keys, plus countless incidental construction costs that a subsequent buyer does not pay. In your model, you are tenants in your own house and you sell it in the end with a backlog of renovations.

You should decide: rental apartment and "living" or building a house and living for the house, that doesn't mean you can't live with a house but quite a lot of capital goes into maintenance.

Well – to defend the OP here a bit. There are other models than the classic homeownership acquisition models.

For example, purchase according to needs. As an example: If you are young, a condominium in the city is interesting because you are unbound and want to be closer to the "action." If children are present, you want them to be able to play outside without having to go to the playground and "waste" time there. Therefore, many think about buying their own house at that time (if there are small children). When the kids have moved out, the house becomes too big. You yourself are slowly reaching an age where you might look for something smaller and more manageable. So the big house is sold and possibly an apartment is purchased/rented. When the age comes where you rather want to go to a senior residence, that apartment is also disposed of and the saved money is put into the care home. Next stop: coffin.

In this model, you act according to need. It works if the real estate market remains stable (hence the question in a previous post about where in Hesse you want to build). In Frankfurt, you would have the best chances; in rural areas it might be more difficult. That such models can also burst, one saw in 2007/2008 in the USA when the real estate bubble burst (where really anyone earning more than 3 $ could borrow 120 %).

, however, brought a convincing argument against a general 1 % minimum repayment: When the fixed interest period ends, there is a high risk that you will no longer be able to pay the then higher interest rates. You can prevent this by choosing the fixed interest period to end when you want to sell. BUT: What happens if after 20 years you still don't want to part with your beloved home? Then you are sitting on a very large pile of debt, probably with significantly higher interest rates and significantly lower income. Then you have no choice – you MUST sell.

Therefore, the recommendation to choose a higher repayment rate is justified (whether as monthly repayment or as "fixed planned" special repayment).