Floor plan design of a 9x13m gable roof house with an attached 6x9m attic

The other variant without a long hallway, then with a side entrance, is still in progress.

A naive question about the statics: How flexible are the prefab house builders regarding the position of the interior walls on the upper floor compared to the interior walls on the ground floor, meaning, when designing the upper floor, do walls (more than just the walls enclosing the staircase, which are positioned directly above each other anyway) have to be positioned directly above the walls on the ground floor, or can one initially have more freedom in planning this?

I assume that for large living/dining areas and large ceiling surfaces not supported by load-bearing walls, steel beams will probably have to be installed anyway.

In most floor plans seen in house catalogs, the walls on the upper floor are at least partly positioned above the walls on the ground floor.

I have now installed a slightly less deep staircase after consulting with a staircase builder and redesigned the kitchen into a U-shape. The background was the desire to make the living and ground floor sleeping area a bit wider. At the same time, I shortened the house again by 30 cm. I initially did not recess the entrance area inward. If the house could be moved back by 1m, this might be sensible (even though space is lost inside) to create a 1m deep covered area flush with the garage. In the relatively wide hallway, a wardrobe with a bench could be installed (then design the utility room narrower). Alternatively, a wardrobe wall could also be accommodated in the utility room, as shown in the sketch.

Here is the variant with the entrance on the left side (house length not yet reduced here, entrance area recessed inward, slightly wider staircase, and minor differences in the areas of the bathroom and dressing room.)



In principle, I think that with the side entrance you lose even more space due to the large, wide corridor, so I currently prefer the more central entrance (despite the long corridor).

What do you think? It would be great if the experts here could comment on this again. Many thanks!

Here again in comparison the version with a more central entrance and a long hallway

A naïve question about statics: How flexible are prefabricated house builders regarding the position of the interior walls on the upper floor compared to the interior walls on the ground floor, in other words, when designing the upper floor, must walls (even more than the walls surrounding the staircase, which are always aligned) necessarily be positioned above the walls on the ground floor, or can one initially have more planning freedom in this regard?

The experienced planner derives the ground floor from the upper floor, as I regularly point out. How much freedom you have on the upper floor can be influenced, among other things, by the choice of the floor slab there. See also "The upper floor takes precedence" and "Lightweight walls in solid houses?".

I assume that with large living/dining areas and large ceiling surfaces without supporting walls underneath, steel beams will probably have to be inserted anyway.

Most "prefab" house builders build with timber frame panels, where no steel beams are used at all, and even in "solid" construction, the use of steel beams is usually kept to a minimum.

At times, I felt like I was on an oriental bazaar or at the mercy of local planners and monument protection (the half-timbered house on the right is a listed building).
They also didn’t want to accept more than 50 cm roof overhang until I submitted photos of the neighboring houses that partly have up to 1 m roof overhang. Then the colleagues were also satisfied with 1 m.

What do you expect? You have to admit that your construction project simply does not fit the old street section, where monument protection also applies. And there it’s a give and take with the conservative building authority.
But I think that’s okay. That way, misuse is prevented.

I currently have a clear height of 2.65 m in my 3D program for both the ground floor and the upper floor.

What are 2.65 meters good for? That’s an amateur program to arrange furniture, it doesn’t replace professional planning. That’s why I always say, plan a lot of buffer everywhere; otherwise, the professional planner can’t achieve what you want. Such a program practically has no ceiling or screed planning.

In most floor plans you see in house catalogs, the walls on the upper floor are at least partly located above the walls on the ground floor.

I ask myself every time what you mean by prefab house. Many generalize this term.
Prefab house manufacturers build using timber frame construction/prefab construction method, among others with wood or panel elements.
Many walls often lie on top of each other because simple room planning works out well. There is usually no reason to shift a wall by 30 cm if you make sure that all rooms for a four-person family (the manufacturers’ largest target group) can be used flexibly.

A naive question about statics: How flexible are prefab house builders regarding the position of the interior walls on the upper floor relative to the interior walls on the ground floor, that is, must one always position walls on the upper floor (even more than the walls bounding the staircase, which already lie on top of each other) directly above the walls on the ground floor, or can one initially plan with some freedom here?

It’s not the walls that are statically relevant, but posts and beams. These are then connected with walls. Where the load-bearing post is located, you won’t see that later.
By the way: the corner on the ground floor of the airspace/opening in the ceiling will probably also have to be supported by a post.

or can one initially plan with some freedom here?

Yes, you can have some freedom here.
However, the architect-designed houses from these companies (Schwörerhaus, Weberhaus, etc.) are quite expensive. Ultimately, it’s about individualization that occupies the entire production line, since one has to enter and produce complex individual dimensions.
I recommend either modifying a manufacturer’s standard house or commissioning a small regional company and an external architect. Carpentry workshops often also have an architect available. The most flexible option is of course a solid house. The masonry is only laid on site.

Prefab house manufacturers almost exclusively work with Glatthaar. However, they do not offer basements; then you have two contractual partners.
But you probably know all of this, right?!

Personally, I see some problems here that you should clarify for yourself now. Also regarding waiting times for production and erection of prefab houses.

How is the garage supposed to be built, by the way?

Now I have to quote myself because I searched for your budget and only stumbled upon my list.

Costs: €540,000 for 180 sqm of living space, plus a basement of €120,000–150,000,
double garage €40,000
That’s €700,000–750,000
…

€3,000/sqm relates to average standard with common own contributions.
Adjust that with airspace, stair landing, and some constructional extras as well as an individual prefab house with at least €3,500.

Honestly, I would first check with a few companies whether they would build such a house within a price range you have in mind. Also, how it looks with garage and basement and individuality compared to the house price.
Because I have a suspicion that you are orienting yourself to catalog prices, which are bare and without base slab, linked to a simple construction service description.
And now you are cheerfully drawing your 180 sqm and later can’t find anyone to build it or only start clarifying substantial things afterward.

What are 2.65 good for? That’s an amateur program to set things up, it does not replace professional planning. That’s why I always say, always plan a big buffer everywhere, otherwise the specialist planner won’t get close to what you want. Such a program basically has no ceiling or screed planning.

I wonder every time what you mean by prefabricated house. Many generalize this term. Prefabricated house manufacturers build using timber frame construction/prefab construction style, among other things with wood or panel elements. Many walls often lie directly on top of each other because the rooms are simply planned very well. There is usually no reason to shift a wall by 30 cm if you make sure that all rooms can be used flexibly for a family of four (the manufacturers’ largest target group).

It’s not the walls that are structurally relevant, but posts and beams. These are then connected with walls. Where the supporting post is, you won’t see it later. By the way: the corner on the ground floor of the air space/cutout of the ceiling will probably also need to be supported by a post.

Yes, you can move a bit more freely. However, the architect-designed houses from these companies (Schwörerhaus, Weberhaus, etc.) are quite expensive. Ultimately, it’s about customization that consumes the entire production line by requiring complex individual dimensions to be entered and produced. I recommend either modifying a standard house model from the manufacturer or commissioning a small regional company and an external architect. Carpenters often also have an architect on hand. Of course, you are most flexible with a solid house. The brick is only laid on site.

Prefabricated house manufacturers almost exclusively work with Glatthaar. However, they don’t offer basements, so you would then have two contractual partners. But you surely know all that?!

Personally, I see some problems there that you should clarify for yourself now. Also regarding the waiting times for production and installation times of prefabricated houses.

How is the garage supposed to be created anyway?

Now I have to quote myself because I was looking for your budget and only stumbled upon my breakdown.

3000 €/sqm refers to average standard with the usual owner’s work. Correct that with air space, platform stairs, some structural extras as well as an individual prefab house with at least 3500 €.

Honestly, I would first clarify with a few companies whether they would build such a house within a price range you have in mind. Also, how the garage and basement and individuality affect the house price. Because I suspect that you are orienting yourself on basic catalog prices, which are bare and without foundation slab tied to a simple construction service description. And now you are merrily drawing your 180 sqm and later find no one who will build it for you or only then start clarifying substantial matters.

What the building preliminary inquiry states: I had a total of 3 preliminary meetings with the building regulations office in which I sketched out my ideas, and in NONE of these 3 meetings (called "citizen building consultation") were concerns raised regarding my plans. I have great understanding that a building project must fit in according to Para 34, but I have less understanding that there apparently are no clear and transparent external criteria within which one can create a plan that then also has validity. When, in the same neighborhood, freshly built houses stand that obviously do not "fit in" at all in terms of external dimensions, roof overhangs or the size of sealed areas and clearly violate exactly the parameters questioned in my project, one unfortunately gets the impression that double standards are often applied here. But that doesn’t help.

I have already budgeted 3500 Euros plus basement and garage. My idea was to go to some providers with a floor plan idea and the external dimensions (both "solid construction" as well as timber panel or timber frame construction) and obtain customized offers from providers there. I have already had talks with 4 providers. It is quite possible that there are standard houses available that can be suitably adjusted. I have already created an Excel-based catalog with the respective construction service specifications in comparison from about 10 manufacturers. I would also use this both to select providers that I consider suitable ("all from one source" is mandatory) and to have the possibility to make the offers reasonably comparable. Many manufacturers now also offer house, basement and garage from a single source (but, as you rightly say, often work with Glatthaar together), which means that ideally you then only have one contractual partner.

Regarding the garage, I am actually thinking of a precast concrete garage, as it requires somewhat less space and should also be cheaper. However, I am also open to building the garage in timber construction if it does not take up too much width. A somewhat narrower garage (e.g., 5.50 m) in favor of a somewhat wider house is also conceivable if this brings advantages in terms of the potential use of a standard house.

However, after reviewing many catalogs and visiting prefab home exhibitions, I am a bit skeptical that I will find something suitable from the catalog with the desired room layout aimed at two people, the entrance on the gable side, and the dimensions.

What is important to me first is to gain some certainty that the floor plans created with your/your team’s help make sense.

I have another meeting with the district planner at the building authority in two weeks. There I can also clarify how much flexibility is available there to shift the garage and/or house a little +/- 1 m relative to each other if that should bring advantages in terms of floor plan planning.

It would therefore be great to have 3 questions answered:

Do the two ground floor floor plan proposals make sense in terms of room sizes, room layouts, and corridor widths? Which of the two ground floor floor plans would you then favor?

What potential advantages would arise in your opinion if the house or garage could still be shifted longitudinally relative to each other by about 1 to max. 2 m?

Many thanks