Building with an architect or turnkey

Hello,
we want to take the plunge and build a house (approx. 160sqm).
Now we are torn back and forth about the best way to do it.
We hardly have any knowledge about the whole matter ourselves. However, we have many people in the family and circle of friends who come from the construction industry and have offered help.
My brother has also just built a house and is therefore completely familiar with the topic.
He only had the execution plans/statics/thermal insulation done by the architect, and then awarded everything himself. That worked out great because he also got a bit of support from a friend who is a site manager (and above all, a few good tips for good and affordable companies).
My brother has now offered to completely take over obtaining quotes and coordinating the various trades for us.
He already has all the offers he received anyway and would then obtain quotes for us from the cheapest companies.
Excavation and probably also the foundation slab will be done entirely by my brother-in-law, that is already certain.
We would also have acquaintances for the roof truss and roof tiles who would do that. And possibly for floor coverings and wallpapers as well.
Everything else should be done through companies.
Now we don't know if it makes sense to accept my brother's offer to take over obtaining quotes, etc. for us. We would only do that if we would definitely save a lot of money.
If a completely turnkey house is not much more expensive, we would save him and ourselves the work.
What do you think, do you have any assessments?

If people voluntarily do unpaid work, that is likely cheaper than paying someone for it.

Whether you want to undertake building a house, the success of which depends on a group of volunteers, only you can know.

However, material still costs money, no one will give that to you for free. I can also imagine that it is very difficult to estimate the construction costs – that probably won't be an advantage for the financing.

Well, the topic is "architect or turnkey," but you can also build turnkey with an architect. In my opinion, you are comparing apples and oranges a bit. Either doing everything "yourself" or handing over everything turnkey is quite contradictory. Maybe the golden mean is the right solution.

You need an architect anyway; which service phases you commission him for is up to you. Getting offers and awarding contracts also doesn't cost much percentage-wise with an architect. But you can also do that yourself...

Surely, you can save a lot of money if you do a lot yourself or with friends... For example, I would let the structural contractor do the foundation slab exclusively. Consider that if something doesn't fit later, everyone blames someone else. And having a friend do it, well...

I am of the opinion that the house should be weather-tight first before I lay hands on it. There is a clear limit regarding warranty cases and after that still enough trades for doing it yourself and saving. You can still talk to the structural contractor about individual self-performed tasks, but with a foundation slab, I would assert you won't find a contractor who will agree to that and later provide a warranty...

Just out of curiosity: do your brother-in-law and acquaintances do the foundation slab/painting etc. for you alongside their regular job, or is it their daily bread and butter and you would basically be a customer, just with better conditions?

If the former, you should consider what happens if they don’t manage it in time!
Can your relationship with your brother handle it if something goes wrong with the schedule and you have to pay rent for an extra month “because of him” or something similar?

There are families where this works without any ifs or buts. If you don’t belong to them, you should keep your hands off it.

When I, as a well-known electrician, offer my help, it doesn't automatically mean that I will wire the entire house. Maybe I sacrifice an afternoon and give tips, later make one or another change in exchange for a barbecue evening, but for wiring a whole house, I would have to take time off, and that needs to be properly compensated.

Please go through this with all friends and acquaintances, and if the commitment of the helping hand is really supposed to be binding, check the reliability and feasibility. A tiler won't do you any good if, when the time comes, he's on holiday in Mallorca. And all of this naturally without guarantee - who likes to warn off friends anyway

Otherwise #3

I don't worry at all about the foundation slab; my brother-in-law also did that for my brother (with the help of his best friend, who is a concrete worker and has already completed hundreds of foundation slabs). For my brother's shell builder, that was also not a problem at all, since he knows the concrete worker well.

The question is whether it makes sense to hire a [GÜ]. I have often heard that it is supposed to be cheaper than building with an architect. Does that still hold true if you take things out and do them yourself? Or is it cheaper in that case to build with an architect and directly plan which things can be done yourself?

I also find it difficult to compare. To get offers, I first need a drawing. But the architect won't just make that for me if I don't even know whether I will ultimately hire him. And it’s probably similar with the [GÜs], right?