Prefabricated house or solid house and which heating?

Good morning dear community,

my wife and I are considering building a house on a plot with a slight slope. Whether a basement is necessary or not is still open and to be clarified. The plot is family-owned and still needs to be developed.
My wife (lawyer) and I (engineer) are both clumsy and have no idea about house construction.

This week we had a first consultation at Streif Haus for a prefabricated house to get a feeling for the numbers and the matter. What we heard there all sounded very great and promising and it is certainly also affordable. The gentleman recommended the air-to-air heat pump from Proxon. The principle also sounds promising, the heating and electricity costs are low, and if you build Kfw 40+ you even get a subsidy on top. All terms that are new to us and that we have heard for the first time.

If you research a bit, you find out that you can probably save a lot of money if you outsource services like the foundation slab or possibly the basement. Whether that then becomes a skill with the planning I can’t judge now. What we have also seen so far is that a solid house is not necessarily more expensive or cheaper. Can you also achieve the KFW 40+ standard with a solid house?

Currently, we don’t know where to start. Should it be solid? Which heating? Air-to-air heat pump or this trench collector we have read about? Maybe one should first have the site and elevation plan created and see what is possible?

We are still at the beginning with many questions and the house is supposed to be permanent.

Maybe you have some tips or answers to the questions or your own experiences

Thank you very much

Good morning Fetzerino,

nice that you have found your way into our community. Welcome! One of the best features of such a forum is the gradually growing availability of all kinds of information on all sorts of topics. You will also find plenty of content here related to the questions you asked. They may not always be revealed easily by the forum search engine (Google usually works better there), but they definitely exist, so I can only recommend that you spend a few hours here to "browse".

In short:

[*]Whether prefabricated, timber frame, or solid house (there are also solid houses in prefabricated form), it is mainly a matter of taste or attitude. I am still firmly convinced that typical prefabricated houses (made of wood) are generally more expensive than solid ones, but otherwise they are at best equally expensive.
[*]An air-to-air heat pump (air-to-air heat pump) is only suitable for houses with minimal energy demand; this usually means a passive house, which requires significantly less energy than KfW 40(+), so from a long-term cost perspective, it would (probably) not be a good recommendation.
[*]KfW 40 with or without Plus can be achieved with both construction methods.
[*]Whether individual services can be more cheaply contracted out yourself depends heavily. Many providers offer good inclusive prices—also due to their purchase volume and corresponding contracts—that also include project management (which also costs). My opinion: As long as a mid four- to low five-figure saving cannot realistically be achieved here, I would leave it. A construction project benefits most from routine processes, which can be severely disrupted by "external" craftsmen.
[*]Trench collector belongs to the subject area of geothermal heat pumps, which is basically a more expensive but very efficient and reliable heat source. That would be one of the decisions (which heat generation: air-to-air heat pump, air-to-water heat pump, brine-to-water heat pump, gas, ...) that I would make in advance—but please based on solid grounds and concrete characteristics of your plot, because, for example, geothermal energy does not work equally well everywhere.
[*]Apart from the heating, I would first visit a model house park to get an idea of "your" house. But that does by no means imply a particular construction method. Instead, also approach providers not represented in the park.

One more tip on the side: A building project is always more expensive than initially thought, so I hope you already have a larger (five- to six-figure) financial buffer with the numbers you know—just generally speaking.

Now I have written more than I wanted, but that should not keep you from skimming through the forum.

Best regards

K1300S

Currently, we do not know where to start. Should it be massive?

Not having fixated on a specific supposed philosopher's stone when building the wall is not a lack of information, but the foundation of a less restricted choice. Honestly: you can build flawless houses from most building materials, despite all the horror stories sellers tell about competitors' products. There are even reportedly satisfied owners of plastic windows, but don't tell anyone. You already have the actual beginning, and if nothing more than the completed development is missing, then that's already great. The rest will come together.

There are even supposed to be satisfied owners of plastic windows, but don’t tell anyone h.

Phew! *wipes a drop of sweat from forehead*

Yes, plastic windows will do.. I still find them ugly. If the wallet doesn’t allow for anything else.

He probably does not do this in an estimated 80 percent of all construction projects in Germany.