High construction costs with rising building interest rates

On the one hand, this is not complaining, but simply an informative discussion on the topic for me.
Also, I just embarrassingly noticed that it’s about 5k net, not 5.5k. But that doesn’t make a big difference.
I am also aware that this is still quite doable for two people, but also financing over 35 years.
If you had built 5 years ago, the construction costs for the same house would have been significantly lower.
Everything is prescribed: heat pump is mandatory for us due to the new housing development, large photovoltaic system on the roof is required.
My parents paid off their house for less than 1000€ per month in about 20 years, but yes, they also earned less on average.
What comes to my mind for many is the question:
1500/month (currently more like that), 500€ ancillary costs (is that even enough?)
At least 2000€ fixed per month for living, rather more. Can that really work well for people? My thoughts are -> do you have to be able to bear something like that alone? For me that would be sensible, but with children I guess that’s not the reality.
AND we still live cheaply in comparison, so I wonder how the middle class in Germany can still afford this (or not, not everyone wants to own a home… which is also fine).

It is always pointless to compare different generations or times as if there were a "back then it was better or worse." That just doesn’t work!
Your parents were also calculated a loan over 30 years. With diligence, you can manage it earlier. My parents took 40 years to pay off. It depends on individual situations and perspectives. One person complains or whines, another wants to compare apples and oranges. Imagine if the previous generation (your great-grandparents) wanted to compare that they still had to accommodate refugees—every room was good for that—in a house they built with their own hands.
My grandparents told about it, but never compared. Rather, they saw it as an innovation that there were construction companies that built a house for you without a coal cellar but with great gas or oil heating.
I belong here in the forum to those who have newly built, and after 10 years I am still at it. I could now complain that I was advised to build the roof surfaces in an east-west direction, but I won’t.
However, I note that houses always have to be bigger. Without a double garage, calculations hardly even take place anymore. And then a pantry, children’s bathroom, dressing room, and show kitchen, possibly a pool. These existed in the 80s as well as in the 2000s.
It's just that people don’t look for possibilities of what they can achieve, but dream a lot and see things negatively that are not negative.
Now my husband and I are going to put up a front garden fence—after 10 years, we are treating ourselves to a fancy wooden fence. Clearance stock. And for us, it is a matter of course to install it ourselves with only €4,000 net—without comparison. It’s all a matter of attitude and perspective.

500€ additional costs (is that even enough?)

Additional costs for rent and house are almost the same, a new house is rather cheaper compared to an old building.

My thoughts are -> do you have to be able to handle something like this on your own?

Nope. Why? Never had to be able to either If you want to be free of all worries, then yes. But then there isn't much left in life if you always need suspenders, braces, and a parachute at the same time because you only see problems.

therefore I wonder how the middle class in Germany can still afford this

Just do it without too much fear. Of course, with respect for numbers and proper calculation. And without a fully basemented 200 sqm + at least a double garage and KNX and two terraces and 350 new plants from the gardener, etc.
In the past, this was called being "down-to-earth." That has been lost over the last 10 years due to cheap money.

however also financing over 35 years.

what should be so bad about that. I don't know it any other way. A decision for a house has its price, then other things are done less or not at all. That has never been different on a broad scale.

If you had built 5 years ago, the construction costs for the same house would have been significantly lower.

You simply live in the time you live in and every era has its advantages and disadvantages. If you had been born much earlier, you would have known hunger and war, the children of today might lick their fingers at your current conditions that you find so bad. We have today, nobody has a contract that they get it the way they want!

All things are prescribed: heat pump is mandatory for us due to new development area, photovoltaic large on the roof compulsory.

Same answer as just now. Life is just mean. In the past everything was probably always so good, simple and cheap. Heat pump is certainly not mandatory and even if it were, there would be the cheaper air-to-air heat pump. We consume very little energy, that can also be controlled, e.g. through discipline and that has never been different either.

My parents paid off the house in just over 20 years for under 1000€ per month, but yes, they also earned less on average.

Bring the whole comparison and not just without any context so that it has to feel bad for you. Honestly – do you like to suffer?
Show all the conditions of your parents' house, substance, equipment, etc. The small semi-detached house of the "Neue Heimat" of my parents cost about 50,000 DM in 1960 in equipment and quality that is below a modern Poroton brick garage. A single oil stove in the small living room, running cold water, no insulation in the roof and the children's room there, and of course no heating, long live the hot water bottle. I come from an older generation but would never think my parents had it so easy or complain about these experiences; that's just how it was. My parents paid it back as quickly as possible, they never traveled, were almost never in restaurants, etc., how about you, let's get to the point.
These recurring comparisons with houses from back then are totally crazy and can only serve to feel bad or disadvantaged yourself (completely without reason), so what is that supposed to be good for I ask myself.

Money is available, even almost 100k

In about 10 years as a couple with this income and without interest/market gains, that suggests a rather low savings rate, where did the monthly money go?
I also had no money at your age, but I was aware that I had spent it all on all sorts of things and therefore knew why I didn’t have a house yet, while peers did.

In the past, one used to say "being down-to-earth." That has been lost in the last 10 years due to cheap money.

In addition, many people are constantly shown "showcase houses" on social media, creating the feeling that they want that too because apparently everyone has it.

I am more of the underdog here and can count myself lucky to have found something six years ago. Today, I wouldn’t see any chance at all.

Since I am a single parent with two increasingly adolescent girls and therefore there is only one income (and child benefits, no maintenance), we still miss the 5k net household income today.
Our house is minimalist for that reason: everyone should have their own room, plus a living room, kitchen, bathroom, and guest toilet. Small utility room and that’s it. The detached house measures 10.5x7m on about 300 sqm of land.
You won’t find children’s bathrooms, a basement, garage, pantry, or pool. The terrace and parking space were completed in the second and third years after moving in. Most recently, in 2023, there was photovoltaic.

We are not poor people. We afford the house (about a third of the money goes into it) and otherwise enjoy luxury in moderation. Winter vacation is set, in summer it’s only a few hundred euros for a holiday apartment. Last autumn we were just barely four-figure in Croatia.

The most expensive luxury is my horse, which has been around much longer than anything else (including children, the single parent status, or the house). My alter ego is now also somewhat aged and you notice that financially in more frequent vet visits and additional necessary feed. This now has to somehow work, but it’s not really comfortable.

Many other wishes have to take a back seat, we cannot live to the fullest and have to set priorities.
I would have really loved to travel to the western USA again, but the budget is not there. I’m almost glad that the trip is out of the question at the moment, thanks to the Orange Man anyway.
For the house I actually wish for sun protection and a terrace roof.
Savings rate for a new car sometime? Currently zero.
Special repayment? Let me laugh.

What do I want to say? We have a house with the “necessary” for nice living and not much more. We consider which luxury we can afford and have to give up fulfilling wishes elsewhere.
If we cut all luxury, we could probably still get by with 1000 euros less. It’s still whining on a high level.

To live to the fullest with consumption/vacations, having every feature for the house, still saving properly, the woman staying at home without income with the children — you will very rarely be able to have all that together. You have to consider what is really important and where you would accept compromises.