Prefabricated house providers - What should you pay attention to? Is there anything unpredictable?

- Earthworks included can mean pretty much anything, just not what you expect. Either only the first 30cm are meant or the disposal is missing or...
- Base plaster is often missing
- Roof undersides often only have primer
- "Painting work" includes much more than just painting walls
- Fire protection switches are often billed separately
- likewise fall protection for floor-to-ceiling windows

these are rather minor things. It gets interesting during the selection process when you're stuck and suddenly every socket costs 100€ or the washbasin is three times the recommended retail price. Also, roller shutters are often unnecessarily swapped for gold afterwards. That’s why you should have your wishes included in the contract. Packages can still be negotiated before signing.

I don’t understand why the topic of the base slab is criticized so often. On the one hand, it is one of the first topics that arise when you deal more intensively with the subject of house construction; on the other hand, it is rather the rule than the exception that "from top of base slab" is offered (of 13 companies I gathered, 9 do not include the base slab in their offers)

In other words: at least 4 of the 13 companies from your supplier field share my view. The criticism is quite simple: when houses with basements were the norm, it made sense to leave out the complex masonry part "basement" in timber-frame prefabricated houses, as companies from a different construction sector that are correspondingly differently positioned carried out that work. However, the exception "without basement" currently has more than just a trend toward becoming the rule—and accordingly, it makes sense to reconsider the approach to the offer: the base slab is a small add-on. On the one hand, it consists of so few trades that it can easily be delegated to a subcontractor; on the other hand, it essentially consists of points that are interfaces to the building erected on it. Viewed from this interface perspective, it corresponds almost only to the ceiling of the basement. From a construction management perspective, offers from top of base slab do not make sense (precisely because the separation of responsibility for compatibility here is not appropriate). However, the price of this position can already exceed the difference to a competitor’s offer. Therefore, the price indication without the base slab is morally dubious, even if legally there may be nothing to complain about regarding the font size of the notice (and several competitors handle it the same way).

What are your experiences, which items does prefab house provider A have, but provider B does not?

How are we supposed to know your offers from provider A and B and your needs?
You have to evaluate that yourself. It is also about getting your wishes realized. If you don’t care about the energy saving ordinance, then you don’t need the one who wants to build KfW40 for you. If you absolutely want a wooden front door, you have to raise the offer from the plastic provider by one item.

I don’t understand why the topic of the base plate is so often criticized.

Me neither. OK, base plate is straightforward and explains itself. There are quite different items that tend to be hidden and result in a massive increase in the offer.
Since you have to deal with the subject of house construction anyway, you know what OK means and that different types of “subfloors” can be used, e.g. if you want a basement.
To get an offer for a “whole house,” you have to go one step further and have an individual offer calculated according to your wishes. You do that with the one or two providers that are in question. Because after all, the choice is not only about the price but also about trust.

There are quite different positions that tend to hide and become a massive increase in the supply.

What hidden positions are those, from your experience?

What hidden positions are those, based on your experience?

Look in the subforum Construction Costs. There are even pinned posts that make reading easier for you. The search system works very well with "Bauleistungsbeschreibung" or "Bauleistungsbeschreibung." A lot comes up.

The basic problem is that construction service descriptions clearly state what is included, but everything that is still missing is only mentioned marginally and incompletely. That means you have to read many construction service descriptions, and then you keep finding new things that are included with some companies and therefore apparently missing with other providers.

And always read between the lines: "Window sills tiled in the bathroom" means: there are no stone window sills in the bathroom, even if a window is outside the tiled area.

A "large selection of sanitary objects" means, for example: exactly one terrible run-of-the-mill faucet is included, the large selection is then available for an additional charge...

and so on, and so forth.