Which software is used for floor plan design and modeling?

What use is a self-developed floor plan that may not even be buildable or affordable.

Well, most people here tend to build according to the architect’s or an existing plan.

Whether catalogue or individual floor plans: financing cannot be clarified with (virtual) model building, but it can be assessed (only visually or also tactilely) in one’s own imagination whether the house idea "works" like this. Only a few builders can directly translate drawings into "3D" in their imagination. The financing component would then require a software component where "every excavator bucket costs." In this respect, the suggestion by Junior "Minecraft," where you first have to craft and cheat your material, is quite good, even though I otherwise regard it more as a smile-worthy proposal from a house planner’s perspective.

In short: wasted time for everyone involved!?!

At least in the case of Lego, no. You can involve the whole family, whereas according to my forum experience, planning software is usually only used by "him" OR "her," and the other part of the couple behaves passively, not to mention the kids.

Many think they have to build with a general contractor (GU) to save themselves the architect.

No, the vast majority expect relief from coordination by a GU, anticipate in return a markup on the sum of the individual contract prices, and assume that this is only to compensate for the included clerk of works.

The experience is something everyone probably has to make themselves. Personally, I found it very pleasant no longer sitting up late into the night on SH3D, trying to recreate some floor plan from the internet only to realize it doesn't work anyway... those few thousand euros paid to an architect were pure gold.

I personally found it very pleasant no longer having to sit late into the evening on SH3D, trying to recreate some floor plan from the internet only to find out it doesn't work anyway...

in my eyes, this is a necessary learning phase, to be able to read floor plans and imagine, recognize bottlenecks and missing rooms, walk-through rooms, hallway bigger than living room, etc. If the architect delivers the perfect floor plan, but the client cannot read it, it doesn't help either. Therefore, every engagement with floor plans trains the future builder.

I personally found it very pleasant no longer to sit on SH3D late into the evening, rebuilding some floor plan from the internet only to find out it doesn’t work anyway...

Attention, dear children! - the internet does not check floor plans for functionality before upload! :) What was the reason in your case specifically: did you take un-dimensioned floor plans and not determine the measurements, or did you vary the floor plans - or does the not working at all even relate to your objection about financing, and you rebuilt templates that were too large?

Attention, dear children! - the internet does not check floor plans for functionality before upload! :)
What was the issue in your case specifically: did you use unmeasured floor plans and not determine the dimensions, or did you vary the floor plans - or does the failure even relate to your objection regarding financing, and you reconstructed templates that were too large?

everything you described.

I can recommend cadvilla. I traced the floor plans of the offers and also the property. Over time (almost three years now) I still use the drawing. I also marked every socket here and created 2D derivations.
My requirement was:
The software should not only give a rough overview but also later allow to derive drawings and create or use own 3D objects.
I have certainly invested several hundred hours in it. Currently, I am planning the outdoor area. The possibilities are both a blessing and a curse. You can really get lost in details if you want to plan the access path, curbstones, front garden, drainage, etc. to the exact centimeter.

Here is an example of how the program helped me and how I was able to explain certain "issues" to my wife, for example. Here the question was about the tile height in the guest toilet and whether the windowsill or tiling.
PS: In the end, everything except the top of the windowsill was tiled.