Hello,
We have been in a very similar situation as you and decided against building a house for the following reasons.
Household income 5,500 euros net plus commission payment 6k annually), equity 50,000 euros (painstakingly saved up, since also studying and would be completely used up for incidental purchase costs, kitchen, and buffer for the construction). One might think that for our age (32 and 34) these are quite stable circumstances, at least in our area.
The total loan amount for us would have been 480,000 euros, since plots south of Berlin are quite expensive (at least 300 euros/sqm, rather more). Since you are planning a double garage and surely want some amenities (roller shutters, walk-in showers, etc.), your house construction will be around 300,000 euros. Probably more. We had to make many compromises in the planning. Annoying.
Our financer presented us with initial financing calculations, and we were shocked. Due to the low equity and the desired installment of 1,800 euros, the banks offered interest rates from 2.6% to 3%, with a repayment of 1.5%! After 15 years, that results in an estimated remaining debt of about 330,000 euros. What if interest rates rise to 4-5%? With such a high remaining debt, you won't get a favorable interest rate for the follow-up financing. Oh yes, with the best offer we would have had to pay off for 37 years at the same interest rate. Crazy idea.
We are just realistic now. I don't want to live year after year in fear of interest rate hikes. Saving up even more equity, as you do, means no vacations. Saving every cent. But we also have an 11-year-old child, which would be unfair to her. After building the house, it's not better due to the high installment. And you work 60 hours a week for that.
Therefore, we decided to rent a large, beautiful apartment, which you can easily get in Berlin for 2,000 euros warm, and leave the stress of rising interest rates and maintenance reserves to the owner. We take our equity and have a small holiday home built at the Mecklenburg Lake District and only take out a small loan.
You have already purchased the plot and paid interest. I have to honestly say, we are relieved that we withdrew from the land purchase contract and did not make the final signature.
Maybe my report helps you to approach the matter very objectively again and go through everything, which installment you have at which interest rate, how much additional incidental costs you have per month with a house, and which amenities like vacations and so on should still be affordable. Because remember, the house only belongs to you when the last euro is paid off.
Best regards, just