If I take the perspective of the bank, it looks as follows: - A property as an investment form is virtually free from total loss. The bank's money is therefore "securely" tied up. - due to the high equity, a loss in value of the house over the term (1% per year) is unproblematic for the bank itself. So the risk in combination is very low. - low repayment means high interest income for a long period. And 1% repayment is not completely out of the ordinary Maybe you can explain the problems to me in more detail. Please primarily ignore the income, that would basically be adjustable. My goal is low financial effort.
The only thing that is really "secure" is the land – and the bank already deducts the hot air in its internal calculation. Unfortunately, the equity is not high; you have not considered the development of the real estate market. For the equity, you probably wouldn’t even get the land, if I interpret the posts here correctly. For your income, excluding maintenance, you probably won’t get more than €200,000 – €300,000 in loans. So this topic is anyway settled.
Your focus – architecture & highest energy efficiency + granny flat, at €180 will mean you can safely calculate over €2,500/m² for your build – regardless of whether you get the building technology cheaply or not. That alone would be > €450,000. Without ancillary construction costs, special architecture, etc. In such projects, you usually need two (secure) incomes, amounting to over €5,000 and at least your equity.
Why should the bank rent you a great architect-designed house for cheap money that you cannot and do not want to afford?