Project house construction. What can I finance?

Then you are by far the only one here. And whether it is enough or not can already be calculated "today."

So? I am also almost the only one here who has installed a ring trench collector. For many here, it is obviously unrealistic to sow lawn or set up a fence. You can calculate whether it is potentially possible. And under the conditions I mentioned, it is possible. If problems arise, you can still arrange interim financing within a very short time until the condominium is sold. And that accordingly frees up a lot of capital in the short term. So there is practically no risk; it simply keeps options open.

But even here you can already see how far apart the opinions are. One says even with selling the apartment it's unrealistic, the other says I should keep it...

The task is to make realistic calculations, not just generally set "interior finishing." For example, floor coverings, sanitary, electrical, doors, wood-burning stove should always be listed separately. If one of these gets out of hand during construction, the others must be adjusted. Also the note about the garden fence: there is a wide range... expensive from a professional or in DIY. We once installed a wild fence. Bought it by the meter, cut it down, and stapled it ourselves to posts. Now we have a garden without a fence. That works too. Opinions differ. If one suddenly wants to call 2700/sqm, then that definitely does not apply to house construction in Lower Saxony. But as the builder you have to stay realistic.

Overall, I also find the opinions too critical. You have 4000 net, even if your wife does not work. If she can earn 1000€ extra, then you have 5000 net. We have a loan of 470k with 5000 net, and as soon as my wife goes on parental leave, the income will decrease. That is a "dry spell" of maybe 10 years, but after that, she could contribute well to the family income again. The only thing is really this apartment, which I would never keep. As the current sole earner, that would be way too much credit for me. And the house construction (especially size) must be adapted to the budget, but many have already said that. We are not getting [Raffstores], our neighbors do not have a single electric shutter... We also do not have ventilation, will probably lay laminate, etc. You do not have to have everything! The prices mentioned I find even exaggerated, although everything in Munich always costs twice as much.

So if the apartment is to be kept, I would also reduce the repayment as much as possible and just rent it out.
That’s how I planned/did it anyway.
However, I’m not really familiar with the area. Is it still influenced by VW? So nothing going on without VW? Or is there more happening because it’s an old university town, etc.?

The proceeds from the apartment are important equity! Currently, it is €40,000! That is not much. It is enough for the kitchen, lamps, and so on, the incidental purchase costs plus the things that inevitably come up and cannot yet be planned... whether it is the fence or whatever needs to be done "later," that will make the financing difficult. Then better to be straightforward and approach it more relaxed with better conditions through equity. If it is sold "in emergency" later, the balance of the financing with the funds is no longer correct. The installment will be higher without equity, meaning the ongoing costs, the house smaller, but then after the sale, there is money, which will be spent in the garden instead of, for example, the painter or tiler, or for 20sqm more living space.

So overall, I also find the opinions too critical. You have 4000 net, even if your wife doesn’t work. If she can earn 1000€ extra, then you have 5000 net. We have a loan of 470k with 5000 net, and as soon as my wife goes on parental leave, the income will decrease. That’s a "dry spell" of maybe 10 years, but after that, she could contribute well to the family income again. The only thing is really this apartment, which I would never keep. As the current sole earner, that would be way too much credit for me. And the house construction (especially size) has to be adjusted to the budget, but many have already said that. We won’t have roller shutters, our neighbors don’t have a single electric shutter... We also have no ventilation, will probably lay laminate, etc. You don’t have to have everything! I even find the prices quoted here exaggerated, even though everything in Munich always costs twice as much.

Exactly these are my thoughts. If she earns 1000€ extra in a few years, everything is fine, they don’t have to be huge amounts. We will get through the time until then. My salary will NEVER decrease, never. I have already mentally said goodbye to the apartment. That was generally my tendency. But I wanted to get a second opinion on that. A remaining debt of 220,000 after 10 years sounds good to me, that could be 50-60% loan-to-value. I do think we can manage that with a total volume of 500,000€. And if not... well then maybe the 500 sqm have to be sacrificed that we sell. Maybe it makes sense to save 10-20 sqm, yes I agree with that. But these adventurous figures that are sometimes mentioned here, I don’t see them in this area. Not at all. Even not for those who modernized or built recently. The apartment obviously depends on VW. It’s directly in Wolfsburg. In the most sought-after district there. But before VW goes down the drain, everything else will go down the drain too. New build apartments here are now at 4000-5000€ per sqm.