Is prefabricated house construction with a solid house floor plan sensible?

How is the building constructed on the slope? If the basement is built into the slope, then one floor is already solid anyway and only the rest is in timber frame construction.

If you like the planning except for very minor details, then take it over. If bigger changes are to be made, then from my point of view start completely anew. Yes, a sloping plot dictates quite a bit, but the architect can also be creative there.

We are completely at the beginning of our house-building journey, so I apologize in advance if the question is totally stupid... We simply do not really know how to best start now.

Then read my posts here under the keyword "house-building schedule" (or the "A house-building schedule, also for you: the phase model of the HOAI!" directly on "Building now"). The cellar question has already been answered in your case, apparently with the result "living basement, and accordingly smaller house above." Most and the most expensive parts of the architect's planning from the sellers are not reusable for you, which is mainly due to the deviations. If I were you, I would benevolently check where there is really a need for changes in the already approved planning. If it suits you, then take the "gift horse" for a reasonable price. Look in the HOAI whether, say, about a third (or generously: 40%) of the "new price" (for the full entry into the architect contract) would be a good deal in the concrete case. For the seller, this effort would be completely wasted without this property, but for you, the approved planning is a very time-saving milestone in the bag. Therefore, my proposal is "a third to 40%" subject to an appropriate architect’s fee. 50k for service phases 1 to 6 sounds big and/or luxurious. Why did you plan to build "using prefabricated construction"? – At your level of building knowledge, this is most likely based mainly on myths & co. I always suggest to my advisees to make a setting of the points (see schedule) during the dough resting phase, i.e., with the result of module A to make an orientation inquiry to usually three masons and three carpenters and to derive from their results whether the architect should then develop the preliminary draft into a stone or wooden design. In your case, the procedure would deviate insofar as the hillside location almost dictates a stone basement (as an exception, I only recall the "plant carpenter"). Not for you, but for the silent readers (about ninety percent of readers of a thread remain "silent"), just to be complete, the question from the headline shall be answered: no, realizing a house based on a plan originating from another construction method is basically strongly inadvisable. For you, the planning of the previous owner’s architect is mainly valuable to the extent that the originally not tailor-made house would also "fit" you (provided the fee is not excessive). By changing the construction method – above all: after the approval! which already sounds really very foolish – you would devalue this usability especially concerning the most expensive parts of the planning to an extent that would really suffice for a guide "Stupidity – How to?".

Then read my posts here on the keyword "house construction schedule" (or the "A house construction schedule, also for you: the HOAI phase model!" directly on "Building now"). The basement question has already been answered in your case, apparently with the result "residential basement, and accordingly smaller house above."

Thanks for the hint, I will search the forum for that. We are actually still somewhat clueless because due to this situation we simply don't have to proceed according to a set scheme. On the one hand, we decided on the plot because we could already imagine the house well thanks to the architect's plan, on the other hand the prefabricated plan somehow also disturbs the discovery phase.

Most of the parts planned by the architect of the seller are not reusable for you, especially the expensive ones, which is mainly due to the deviations. If I were you, I would benevolently check where there is really a need for changes in the already approved plan. If it suits you, then take the "gift horse" for a reasonable price. Look at the HOAI, whether around one third (or generously: 40%) of the "new price" (for full entry into the architect contract) would be a good deal in the specific case. For the seller this effort would be completely wasted without this plot, but for you the approved plan is a big time-saving milestone in the bag. Therefore my suggestion: "one third to 40%" under the condition of a reasonable architect’s fee. 50k for service phases 1 to 6 sounds like something big and/or luxurious.

The architect estimated the costs at about 1.4 million (including the plot) in 2022. However, he also said that it was very luxuriously specified. So we hope to come out somewhat cheaper. There are about 100 sqm per floor and a double garage in the basement. But you would only pay the 33% if you mostly took over the plans (including construction method), right? If I have to commission my own design plan anyway afterwards, it would rather be paying more.

Why had you planned "to build in prefabricated construction"? – at your level of building knowledge this is most likely based mainly on myths & co. I always suggest to my advisees to make a critical decision (see schedule) during the dough rest , i.e. to make an orientation inquiry to usually three masonry and three timber builders with the result of module A and to derive from their result whether the architect should then mature the preliminary draft stone or wood into the design. In your case this procedure would differ insofar as the hillside location almost dictates a stone basement (as an exception I only remember the "perennial woodworker").

Actually, we have only heard positive things about it from acquaintances and we are considering if possible to get a YouTube cooperation with a prefab house provider. Such advertising of course makes more sense for large supraregional providers than for the regional construction company.

For you, the planning of the previous owner’s architect is mainly valuable insofar as the originally not tailor-made house for you would "fit" (provided the fee is not excessive). With the change of the construction method – especially after the approval !, which already sounds really very foolish – you would devalue this usefulness precisely with regard to the most expensive parts of the planning to an extent that it would be enough for an advice "stupidity – how to?"

At least the approval is helpful in that you can rely on it at the building authority (there is no development plan) and we know what height and size can be built on the plot... But of course we do not have to buy the planning for that.

On the one hand, we chose the plot because, thanks to the architect's plan, we could already well imagine the house; on the other hand, the prefabricated plan somehow also interferes with the discovery phase. [...] The architect estimated the costs in 2022 at about 1.4 million (including the plot). However, he also said that it was very luxuriously specified. So we hope to come out a bit cheaper. It is about 100 sqm per floor

Just as the discovery phase itself is no value in itself, it does start with you, i.e. your needs, wishes, and the like. Would the budget correspond to your possibilities, and the size to your needs? And did I understand correctly: you fell in love with the plot directly in connection with the fact that this house fits on it and would be approved? 1. Have you known the sellers for a longer time than their withdrawal from their own realization of the planning; 2. where does this withdrawal come from?

and double garage in the basement.

Is it then even a "basement" if the garage is accessed on the valley side / would the entrance also be (supposed to be) on the lower floor? The plan

But you would only pay the 33% if you took over most of the planning (i.e. also the construction method)? If I still have to commission my own draft plan anyway, then it would rather be an additional cost.

I consider the planning purchase option exactly meaningful then and to that extent if and as the building-permitted house would fit you. So if more or less the labels "Child 1," "Child 2," "Work," and "Guest" would be swapped, the bathroom door and the storage room would be in other places, and so on, so that all stakeholders/residents would achieve an upgrade from the current state. The architecture is apparently already approvable, if I understood correctly.

After all, the approval is helpful in that you can refer to it at the building authority (there is no development plan) and we know what height and size can be placed on the plot.. But we don’t necessarily have to buy the planning for that.

As a building preliminary inquiry, the approved planning is at least usable (as long as the application is submitted during its validity), yes.

In fact, we have only heard positive things from acquaintances about it, and we are considering if possible to get a YouTube cooperation with a prefabricated house provider. Such advertising of course makes more sense for large supraregional providers than for the regional construction company.

You seriously dream of an influencer discount as a reference customer if you take a house from a "prefab" house manufacturer? Apart from the fact that this would be equally attractive for any regional provider regardless of construction type, I give this idea five LOL-stars. Tell me (as a title, not as a link!) what the post is called in which your acquaintances have already done this. I think the companies will value that far less than you hope — maybe the wallbox and the fingerprint upgrade for the front door for free, possibly also the facade spotlights. But already with the gabions or the garage door they will show you a bird.

Just as the discovery phase is not a value in itself, it does start with you, i.e. your needs, wishes, and the like. Would the budget correspond to your possibilities, and the size to your needs? And did I understand correctly: you fell in love with the plot in direct connection with the fact that this house fits on it and would be permitted? 1. Have you known the sellers longer than since their withdrawal from realizing the plan themselves; 2. where does this withdrawal come from?

No, we have only known the sellers since the purchase. Apparently, they withdrew from the construction for professional reasons because they are now traveling abroad more frequently. In fact, we liked the house and the plot immediately. With a few changes, it also fits very well to our wishes/needs and would be feasible.

Is it then even a "basement" if the garage is accessed from the valley side / would the entrance also be located (or should be located) on the lower floor?

Correct, the entrance would be in the "basement" next to the garage. Also a separate apartment that we would use as an office. The ground floor with the living rooms then opens out to the garden at ground level.

I consider the option to purchase the planning precisely then and so strongly to be sensible when and how the building-permitted house would fit for you. So if more or less the labels "Child 1," "Child 2," "Work," and "Guest" would be swapped, the bathroom door and the storage room would be at other places, and so on, in other words, all stakeholders/residents would achieve an upgrade compared to the current state. The architecture is apparently already approvable, if I understood correctly.

Actually, we have considered whether we could add a bay window. But before the construction costs rise further, we would stick to the floor plan. The roof is currently planned as a hip roof; alternatively, we are also considering a flat roof. The architect said that would not be a problem.

Are you seriously dreaming of an influencer discount as reference customers if you take a house from a "prefabricated" house manufacturer? Apart from the fact that this would be equally attractive for a regional provider of any construction method, I give this idea five LOL stars. By the way (as a title, not as a link!) what is the name of the post where your acquaintances already did this. I think this will be worth far less to the companies than you hope – maybe the wallbox and the fingerprint upgrade for the front door for free, possibly also the facade spotlights. But already with the gabions or the garage door they will give you the bird.

We don’t have any direct acquaintances who have done something like this. But for example, Weberhaus recently had a cooperation with a soccer player. It is quite a different industry, but my husband is also in the public eye. Therefore, we have made considerations in this regard. If it is not interesting for the companies, it is not tragic. Asking costs nothing. We will also accompany the construction a bit on Youtube anyway.

No, we only got to know the sellers after the purchase. They apparently distanced themselves from the construction for professional reasons because they are now traveling abroad more often. In fact, we liked the house and the property immediately. With a few changes, it also fits very well with our wishes/needs and would be manageable.

Then you would have to be crazy to want to build an already approved house differently (as said, if the architect’s fee is not significantly overpriced).

We had actually considered whether to add a bay window. But before construction costs go up any further, we would stick to the floor plan. The roof is currently planned as a hip roof; alternatively, we are still considering a flat roof. The architect said that is no problem.

... and 11ant says that, in this case, is nonsense.

We don’t have any direct acquaintances who have done something like that. But for example, Weberhaus recently had a cooperation with a footballer. It’s a completely different industry, but my husband is also a public figure. Therefore, we had given some thought to that.

So the acquaintances who like a (which one?) "prefab" house company from their own customer experience are not the same as the example of the advertising partner (?) By the way, I don’t know Reiner Calmund personally either, but I also wouldn’t copy Alexander (whether Zverev or Bommes) regarding where they buy their houses. The developer whose main shareholder is married to the former national coach is, by the way, insolvent.

If that’s not interesting for the companies, it’s not a big deal. Asking doesn’t cost anything. We will accompany the construction a little bit on YouTube anyway.

With a house built using wet construction methods, I would actually see even more possible sponsors.