Is the planned construction cost including the land realistic?

Parquet. Is it with glue and skirting boards?
Rotband for drywall? What about fine filler, Kurt, etc.
Just as an example. Buy or rent tools. Etc.

Still, nothing will get even remotely tight if you don’t go completely crazy on the price of materials and think you have to use only the most exquisite designers.

I actually find the estimate for the outdoor facilities far too low.

Industrial electricians in the industry... no offense, but that has nothing to do with craftsmanship. I am a trained mechatronics technician and electrical engineer... but cleaning, especially outside, laying screed properly, etc. I would never trust myself to do that, there is simply a lack of practice, practice, practice. These are jobs where it has to go fast because the stuff sets, you can see transitions, etc.
Forget it if you don’t have professionals in your circle of friends.

You would have to see the entire construction service description to find out what exactly is meant by "shell house." In some cases, you still have to do the insulation of the exterior walls yourself, etc., etc.

Unfortunately, I don't have the construction service description yet; I'm not that far along. I am currently trying to roughly determine whether we can even afford the whole thing. From what I understand with prefabricated house providers, you "only" have to insulate and panel from the inside and the materials are provided.

Where does one get 50 days of vacation? Or are those accrued overtime hours?

Certain collective agreements with wage supplements (money) that, due to savings measures, are converted into days off.

One more general question: How much does it cost to equip a 160sqm house with screed? As I understand you, it’s probably better not to do that yourself. Does it take so long because it’s a lot of work, or is the long duration due to drying times?

Best regards

Simon

Well, theoretically it is also possible without plaster (formwork outside, drywall + wallpaper inside) and with dry screed or directly wooden floorboards on beam structure. But then it gets more expensive again – although you could save on heating if you no longer install underfloor heating (possible without screed but not optimal).

Screed is simply a dirty job and causes problems afterwards if not done well. Some mistakes are not easy to fix afterwards, in the worst case everything has to be removed and redone. The duration was 1 day for me with 162m² of usable area. And then comes the drying time, yes, but can be drastically shortened with surcharges (but costs) ... Normally four to six weeks, but you can already move in after four to seven days and do some other things (flooring, drywall or insulation not, but I think sanitary works would be possible (if you protect it well afterwards).

I think screed cost me 10,000 EUR. But I can't say exactly because it was a general contractor service and I have no separate invoice. But since my general contractor was very flexible with individual trades in the electronic tender, I had credit offers for almost everything. We did windows and doors as well as screed insulation and part of the tiles (and the standard walls and floor) ourselves and awarded heating and sanitation and stairs and ground floor + bathrooms tiling ourselves.

If you really want to do everything yourself, then I would rather do wooden floorboards on beam structure instead of screed. Heating then only with air/air system and only hot water via heat pump with hot water storage tank (possibly even instantaneous water heater if photovoltaic with storage is planned anyway). If insulating yourself then put in more or higher quality insulation everywhere at the same time.

Is that a Massa Haus or something similar? Don’t they have their expansion packages?

I trust myself to install a heat pump and underfloor heating

Then also think about the specialist and the costs for the inspections.

I’ve never done it before, but there are enough instructions for it, in my estimation doable.

Hobby craftsman

The electrics shouldn’t be a problem

Whether you can now call yourself a jack-of-all-trades and superman because of YouTube videos, I don’t know. Being able to do something or just doing something are two different things. Last year, I also took apart our dryer and fiddled with it so much until it ran again, yet despite YouTube or precisely because of the various vloggers, it was a matter of luck and time-consuming. One weekend went down the drain, including a Saturday night until 2:30 am, because you constantly had to YouTube some info. Try doing that on a construction site, haha.

Maybe you’re in your element with electrics, but that trade is only a small part.
That brings me to this: I wonder what your percentage figures are good for. They are probably fine in another table that relates to your own work, to see how much commitment each trade demands from you.

No, I have no helpers from the construction.

What is missing in your list and your thinking, and will ruin your plans, is all the logistics.

Of course, you can do a self-build house yourself. But not in one year and not without helping hands. If your family and your car are not behind you 120%, later you will have a house, but no wife anymore. The car will be scrapped too, because it often gets overloaded with dirty stuff.

You always need materials again, and you need to know what. For the smaller trades, you have to go to the hardware store. Meaning: workplace - construction site - hardware store - construction site - home, without having achieved anything. You do that five times and no more. You will probably pre-purchase, then you only need 70% of it or 130%, in both cases expensive and annoying.

Working fully during vacation does accomplish something, but also wears out your body—not after 5 weeks, but after 5 days.

The heating system is delivered. Who installs it exactly where it should go? You alone?

The bathtub is delivered. There is no construction staircase, because it costs money. How does the bathtub get upstairs? That also applies to cable reels, etc.
Also, a tall two-story building: how long will the expensive scaffolding have to stay?

Of course, you can anticipate many things by purchasing a garden shed, where the things and equipment are stored. But criminals know that too. You can’t get new stuff fast enough for how quickly construction sites or craftsmen’s vehicles are plundered.

You will have no joy in the additional burden sooner than you think. Breaks or relaxation will be wasted time for you. There will be reproaches—from two sides. Those can last for a long time.
And the superior will watch you more because you are often unfocused, sometimes also sick—in combination with self-build a tricky matter.

So I would position the inspections as well as possibly rework that these companies then have to do, because you haven’t thought of everything. A helper on a 530€ mini-job is also a good investment. A vehicle, an old thing with lots of loading space. The “Brilli” for your wife, conciliatory dinners, but actually think beforehand or calculate whether the savings through own work really pays off. In my opinion (and experience) the final finishing works, i.e. walls and floors, possibly also wooden expansions and kitchen, are already very time- and nerve-consuming, so I warn against the expansion.

The question I ask here: does a bank finance your bills?

phew, I am also a fan of doing things yourself and insist on doing almost everything on your own in one or two years. But this definitely requires more familiarization than I can see.
- Electrical: you absolutely need to deal with what you want and need and how it works, you will regret it if you buy a complete set from eBay and in the end have no outdoor lighting or it is absolutely and everywhere the bare minimum – here you can already waste several weeks in the evenings after work on research and planning (where, which lamp, switch, etc.)
- Screed has been mentioned several times – maybe a dry system is an alternative? Here again, getting familiar is necessary!
- Sanitary and heating – you should be able to pressure test this in the end, and at least know what you are doing and planning (here I have decided for myself – since I am also an electrician – to take on the busy work like laying water and sewage pipes, laying heating loops, installing the hot water tank … but the final commissioning and testing with pressure testing and so on will be done by my brother-in-law – a heating engineer, from whom I can also borrow the pressing tongs, etc. during the process)

And very important, even if the collective agreement allows you a lot of overtime and vacation, assume that with learning and lack of practice and experience you need 2-3 times the time of a professional. That means 2-3 electricians need 1 week for the electrics -> you need 2 months here.
This runs through everything and as mentioned before, this is a strain. Have you ever had a roughly comparable project and do you know that you can handle it? One or two reliable helpers not only reduce the time spent but also serve as motivation (I renovated 2 apartments completely with my father, each about 150sqm and each about 1.5 years – once I was on a semester abroad for 5 months, during this time not even half of what we accomplished together in 5 months happened, because he had only a fraction of the motivation alone on the construction site for months)

This is not to say 'DON'T DO IT' but think about what you are doing before you do it ;)

One more general question: How much does it cost to equip a 160sqm house with screed?

We paid 5,000 euros for pure screed work on 210sqm three years ago. The guys were done in 1.5 days. I would never do that myself. But of course, you can easily lay the insulation underneath yourself. That can be done well in a weekend by yourself.