How much money do you have on the edge?

I once knew someone for whom the special repayment was the highest priority; every free euro flowed into it... when a new car was needed, then all bets were off. He absolutely did not want to take out another loan. There was never any money for anything else either; the partner had to pay for those (meaning the "smaller" purchases, e.g. a new washing machine, which are always occasionally necessary, not the general living expenses). One has to have a reserve of available money. I know the benchmark of three months' salary. And I think many also have to dip into this reserve when building. (Me too). And then it has to be replenished accordingly afterward. But maybe you are in the lucky position of not having had to use this reserve.

this is the typical 'special repayment'. Either you repay off-schedule, then money is missing for such repairs, purchases and you take out an expensive installment loan. Or you do make a special repayment after all because an expensive TV has to be purchased

No, if anything, the imaginary shifts to a higher loan-to-value ratio, which is always offset by stating a lower own contribution, and if done correctly, it even improves because you state a slightly higher own contribution.

Sorry, but I don't know how the outdoor facilities, which are assumed to increase value by 100%, change the loan-to-value ratio in any way. It doesn't make any sense to me at all and has zero application in my daily work with banks.