Basement planning prefab house - outsource? What to consider?

In principle, one should probably trust the prefabricated house provider when it comes to basement construction and not leave it to outside parties?

But if I know which basement builder my prefabricated house company works with, can't I casually get a quote from one of the largest prefabricated basement providers in Germany and have it subcontracted externally?

That's what it's about for me... I think that you could save certain commissions and also surcharges if you inquire directly with a basement builder.

I think you can just make it easy and ultimately have everything done by the prefabricated house provider... sure, that's the easiest way but probably also the most expensive, right?

Am I going in the wrong direction here or is something like this feasible? How did you handle this with your prefabricated house providers? Everything completely from a single source (basement, garage, outdoor facilities, photovoltaics, etc.) or did you also hire external specialist companies for different things?

I think you could save certain commissions and surcharges here if you request it directly from a basement builder.

Batch size several hundred basements/year versus batch size 1. Who do you think gets the better price here?

the easiest way but probably also the most expensive, right?

Am I going the wrong way here or is something like this feasible?

Well, you usually ask yourself something like this before deciding on a turnkey/prefabricated house provider.

How did you organize this with your prefabricated house providers? Everything completely from one source (basement, garage, outdoor facilities, photovoltaics, etc.) or did you also commission external specialist companies for different things?

What is the appeal of building a prefabricated house and yet outsourcing everything externally? Five years ago we were at the same point. Of the major prefabricated house manufacturers (Okal Haus, Streif Haus house, Bien-Zenker) none were willing to place their house on an external basement, the interface issues especially in terms of performance and warranty matters were too hot for everyone, and in the end not acceptable for us.

The question is simple, where do I draw the line? How far do I go?

Garage, patio roofing, general outdoor areas and driveways, cellar, etc...

Everything from a single source definitely does not have to be the case, and you keep hearing that you can save money on one or another thing.

As I said, how it exactly is with the cellar I unfortunately "cannot" say yet. However, I have also read that subcontracting the cellar can save costs! So that is not completely made up.

Of course, the advantage of a prefabricated house is that I do not have 100 different trades, but you can definitely consider whether to bring in a specialist company for one or another point or not?

The prefabricated house companies always come directly with their warranty story... Even with a pergola, which a specialist company then attaches to the wall, the companies come with that... I find that partly ridiculous too.

How far do I go?

That is the question that stands right at the beginning. The entire construct I am entering stands or falls with the answer to this question. Highly individual architect's solution with single awarding of contracts? Massive turnkey construction? Or a highly standardized prefabricated house solution? With all intermediate steps. Trying later to shuffle the best parts between the systems usually goes wrong.

Garage, terrace roofing, generally outdoor facilities and driveway access, basement etc...

Well, garage, your sun protection and the outdoor facilities have nothing to do with the actual house construction; the basement literally forms the basis of the house construction, so you are comparing apples and oranges.

that outsourcing the basement can save costs!

Another tip: You can almost always save costs with outsourcing. Unfortunately, the overlap between outsourcing and prefabricated houses is vanishingly small.

a specialist company

Even your prefab house basement is built by the supplier using a specialist company. Here in the area, for example, Hanse builds with Glatthaar. I think there are corresponding clauses in the contracts that prevent Glatthaar from building basements for Hanse houses bypassing Hanse.

The prefab house companies always come directly with their warranty story...

Of course they do. You want to touch their margin, and they don’t play along but pull the joker. Welcome to prefabricated house construction.

I find that partly ridiculous too.

Then again the question: Why the decision for a prefabricated house? Absolutely everything you list here screams "not prefab house."

The question is simple, where do I draw the line?

I can and would do the garage freestanding and independently, same with the outdoor facilities. OKKD is an interface that is always also a joint, so I would refrain from gambling there.

Of course, the advantage of a prefabricated house is that I don't have 100 different trades,

You have the same number of trades, just not the same number of contractors. A prefabricated house is not less complex, it doesn’t come plotted out of a 3D printer.

I totally know what you mean...

Prefab house because I don’t want to coordinate a bunch of trades and wait 2 years for my house because the planning is just way too complicated and time-consuming.

I also don’t want to constantly supervise the construction and spend weeks on the building site.

I don’t have any of that with the prefab house and that’s a good thing.

It’s just about possibly outsourcing one thing or another to save costs and keep the effort low for me...

But yes, then you should probably do this for things like [Außenanlage], [Garage], etc., but have the whole house structure planned and built by the prefab house provider.