Comprehension question: Gable roof - load-bearing walls - floor plan

Dear forum,

I would like to thank you in advance for the many suggestions I have received by reading the numerous posts in this forum recently. Now it is becoming concrete for us as well: we have been able to acquire a plot of land and are planning to build a single-family house on it.

We are currently still at the beginning of the planning phase and are giving intensive thought to a possible floor plan design. In this context, the question arose as to which framework conditions from the structural engineering side we need to consider: specifically, how "free" are we in placing the walls.

I will first describe our construction project:

[*]we are building on about 105 m² floor area - 12.0 x 8.75 m external dimensions.
[*]we are constructing 2 full floors and an attic as a non-full floor. A basement will not be built.
[*]the attic is to be built as a gable roof, no dormers, roof pitch probably 30 - 35 degrees.
[*]we prefer to build a "timber house," meaning timber frame / timber panel construction or similar. However, we are not fixed on this and it could therefore also become a solid house.

Our questions:

[*]Which form of construction for the gable roof is most appropriate? A rafter roof seems to be the most economical option and possibly does not require supports – is this feasible with our building depth (8.75 m)? Or does another form (purlin roof?) suggest itself, and if so, why?
[*]Do (possibly) load-bearing walls on the ground floor and upper floor have to be "aligned," i.e., what degree of overlap or spatial proximity should we initially consider so that later no (possibly very expensive) special structural construction is required?
[*]Are there dependencies on the (central) roof ridge – i.e., do load-bearing walls on the ground and upper floors need to be arranged as centrally as possible?

To describe our questions a little more precisely, I am attaching two sketches of possible floor plans on the ground floor and upper floor. I do not want to start the discussion about the optimal floor plan design here yet, although I am already looking forward to your suggestions on this!

[ATTACH alt="verstaendnisfrage-satteldach-tragende-waende-grundriss-679773-1.png"]89821[/ATTACH] [ATTACH alt="verstaendnisfrage-satteldach-tragende-waende-grundriss-679773-2.png"]89822[/ATTACH]

We understand that our planning will be checked and confirmed by a structural engineer in due time. Until then, however, we want to orient ourselves as well as possible on the structural framework conditions and hope for your input! This way, we can discard floor plan variants right away that might later cause us major problems.

Many thanks and best regards!

Answering your questions is quite simple. You can basically build any room arrangement you want. Structural feats like widely spanning sections or staggered load-bearing walls cost material and money. Staggered load-bearing walls do not fit with budget-friendly construction.

Aside from that, your first draft raises quite different questions:
1. What contemporary technology should fit into a [HAR] of this size?
2. Why does the staircase have a different format at the top than at the bottom?
3. How should the large living room be furnished without creating a large traffic area in this room? (Or do you want to have space for dancing at any time without moving furniture?)
4. How can such a narrow storage room be used effectively?
5. What limitations on the size of furniture are there due to the narrow staircase / narrow hallway for the first floor?
6. Where are the doors? Where does the daylight come from?

Friends’ daughter built a house with a central staircase. Quite successful. The idea of placing the staircase in the particularly dark area of the house has something to it. I also recognize that the children should get equally sized rooms. Likewise, the desire for a large open living area as a special priority of the architecture. Make exactly these considerations clear in writing and note why you want what where – not necessarily here and publicly, but certainly for an advisor or architect. Walk through model houses. What you will build will surely look different – and that is OK.

Which design for the pitched roof suggests itself? A rafter roof seems to be the cheapest option

No, when used as a storage room, the dry loft truss is rather the cheapest option - somewhat freely spanning and forming the top floor ceiling at the same time; this also makes the layout of the upper floor more flexible.

Do (possibly) load-bearing walls on the ground floor and upper floor have to be "aligned," or which degree of overlap or spatial proximity should we initially consider so that we later do not require (possibly very expensive) special structural solutions?

Load-bearing walls are indeed strongly recommended to be aligned vertically or, better said, one above the other. For that, read (externally, including the quotation marks) "Das Obergeschoss hat Vorrang," "Planänderung: Aus der Beton- soll eine Holzdecke werden," and "Leichtbauwände in Massivhäusern?".

Are there dependencies on the (central) roof ridge – i.e. do load-bearing walls on ground floor/upper floor also have to be arranged as centrally as possible?

Yes and no, not all load transfer needs to be strictly aligned under the ridge beam. In the depicted layout, even if the upper floor were an attic, I see no difficulties.

We are building 2 full floors and an attic as a non-full floor. A basement will not be built.

What do the site and development plan say about this? – Has the 11th basement rule ("With or without basement: a rule as a decision-making tool") been observed?

We prefer building a "wood house," i.e. timber frame/timber panel construction or similar. However, we are not fixed on this, so it could also become a solid house.

Remain open to being surprised during the proofing stage as to which construction method ultimately has the edge in the specific case. Where does the preference come from?

That the children should get rooms of equal size

Is not a value in itself, but usually simply an irrational parental quirk. It only really "makes sense" with identical twins.

Walk through model homes.

But not before getting to know your architect or another independent building consultant. Model homes should really only be visited under medical supervision.

Our questions:

[*]Which construction type for the gable roof is obvious? A rafter roof seems to be the cheapest option and possibly works without supports – is this feasible with our building depth (8.75 m)? Or is another construction type (purlin roof?) preferable, if so, why? [*]Do (possibly) load-bearing walls on the ground floor and upper floor have to be "on top of each other," or what degree of overlap or spatial proximity should we initially consider so that we later do not need any (possibly very expensive) special structural construction? [*]Are there dependencies on the (central) roof ridge – i.e., do load-bearing walls on the ground floor/upper floor need to be arranged as centrally as possible?

These are questions you ask your architect. He first plans so that you manage with little complexity in the statics anyway. If you then have exotic wishes, he will explain to you why this or that is feasible or not. There are many ways to Rome, implementations can be made possible one way or another. Much is possible.

We are aware that our planning will be checked and approved by a structural engineer in due course.

Not for me. It will not be your planning that goes to the structural engineer, but that of the planner or architect, i.e., the expert.

Aside from that, your first draft raises quite different questions:

I am always glad that a house design consists of more than just a floor plan made up of lines/walls or colored boxes that can be compared to Tetris. [ATTACH alt="IMG_1466.jpeg"]89825[/ATTACH] A house is 3D. Starting on a plot, to realize the wishes of oneself and possibly one’s family. Pencil drawings are often more meaningful than Excel or similar programs. And with an idea, one should not be confronted with (non-)knowledge that can inhibit creativity but rather let it out freely.

But not before meeting your architect or another independent building consultant. Show homes should actually only be administered under medical supervision.

That may be so. A warning about the side effects would be enough: May lead to signs of overwhelm in people who have difficulty making decisions.

That may be. A warning about side effects would be enough: Can lead to signs of overload in indecisive people.

While the overeating with building ideas is still in full swing, the subsequent digestive problems are not yet showing. Therefore, the "what our development plan doesn't allow" filter should be applied before the exhibition visit (and preferably already be firmly established in the discussion with the expert). The "antiserum afterwards" tastes bitter/expensive.