Thoughts on an expansion house or solid house

Hello dear forum, I would like to briefly explain my thoughts to you...

I have been thinking for a while about building something of my own. I came across some prefabricated house providers who offer houses in different stages of completion (e.g. the Living series from Bien-Zenker, Family series from Danwood). However, a solid house in such a stage of completion would also be an option.

I consider myself skillful enough to do the plastering and painting myself, lay the floor coverings myself, and assist the electrician and plumbers who are friends in order to save some money.

I am in no hurry; currently, I live rent-free in a two-room apartment at my parents’ place, but of course, that is not intended to be a permanent situation.

Since I want to take on the house completely on my own, the price also plays a role. As I have imagined it (and surely forgot some things...), I will roughly outline it.

Plot: 550 sqm fully developed including resulting costs: €50,000 (price per sqm fully developed €80)

Additional costs: approx. €17,000 (construction site costs such as electricity, connections, sewer work)

Foundation including earthworks: approx. €20,000

House price depending on the stage of completion: €100,000–120,000

Outdoor facilities: approx. €2,000 for initial rough work, fine work would be done after 2–3 years.

Floor coverings and painting things: approx. €5,000 (tiles are included in the house price)

That would bring us to total costs of approx. €180,000–190,000.

Is this a realistic price that is possible? Somehow it seems too low to me. I took the costs from various builders' diaries and found an average.

Could it even be an advantage to hand over the shell construction to a local construction company and tender the trades step by step?

I am already looking forward to your suggestions, information, ideas, and critiques!

Best regards

I can't imagine that you'll manage with that. An acquaintance built with a rather cheap provider or got his "kit" from him and paid about 150,000 for approximately 125m². But he really did EVERYTHING himself, from water, heating, and electrical installation, to wall and ceiling paneling, tiling and flooring, interior doors, sanitation, etc...
Moreover, he stuck to the standard equipment, except for a few sockets and electric shutters.
I assume the house has no basement. What about a garage?
And what exactly do you want to do for 2,000.- on exterior facilities?
Just a staircase (if needed) to the house entrance can quickly cost a five-digit amount. Terrace in EL at least 50.- / m², parking spaces, plants are expensive! etc.

Do you really want to take on a shell house at 24 with financial risks?

Why a house, do you have a family?

In general, there is nothing against it for me if you can afford it and are "heimatverbunden". Building will not get cheaper in the future and the more time you have to pay it off, the better. However, one should not overburden oneself, both in terms of work/stress and financially.

What is included in the self-build house price?

Also electrical/plumbing/interior doors? If not, where is the budget for this?

What is included in the shell house price?

Also electrical/sanitary/interior doors? If not, where is the budget for this?

With the acquaintance, it was like this: the shell was provided, meaning the house including the roof, windows, and front door, and inside there was only a "wooden frame." In addition, there was tons of material, everything needed from the cable to the faucet, which he then used to build the house.
Oh yes, only the screed itself was installed by a company; he did the insulation and underfloor heating beforehand.