solver

Use 2 plans. Difficult to do with Suite. Often done by deleting all the existing structure leaving only the new work.

Ask here: https://chieftalk.chiefarchitect.com/forum/15-seeking-services/

I don't think you can build that stair with Suite. If you just need something to show a stair, try this. You will get a stair that fits in the same space, but will not be accurate.

Search the forum for sail.

Then you need to raise it. You will need to adjust manually.

That's the way it works.

Your "void" is called a stairwell. A search using the programs built in Help, or on homedesignersoftware.com will turn up instructions.

I made a symbol which may work. Import it (Library>Import). It's not a window symbol, but it looks like one, and works in a thick wall. Paint the concrete to match your exterior finish. Untitled 14.calibz

Don't know of any simple way to do the windows. You could use a standard thickness wall, then apply something on the exterior to make it look thicker. Soffits, or Shapes from the library.

No Home Designer product has that ability.

What part has you stumped? If you have a 2nd floor, make a room there with a short ceiling. Create another room inside that one with no roof and a tall ceiling.

I'd send the plan in to support. https://support.chiefarchitect.com/

Slowdowns are sometimes a result of a symbol, or several symbols. The symbols available within the program are optimized, but ones sourced elsewhere may not be. Unfortunately, Home Designer does not have the tools to identify the problem. Does it just "get better", or does it go back to normal? Your computer may also make a difference. If it meets but does not exceed the minimum requirements, you may see a slowdown.

You will need to direct questions like this to the people at Chief Architect.

Does this happen will all plans?

Already available in Pro.

Read about these options.

Export/Import, or copy the User Catalog file from one to the other.

Install them just like you did with Architectural.

You can help us by using a Vector View camera as it shows edge lines making things like ceiling planes easier to see.

Switch to Vector View and take a couple more screen captures. Vector View almost always works best for images to be posted here -- makes it much easier to see problems like this.

Not that I know of. When I create or import a symbol using Chief Premier, I can set some sizing options, but they are limited, Home Designer does not have that ability. Symbols stretch uniformly.

Since you have Pro, and this is such a simple roof, use manual roof planes. You can auto build, but manual is really easy.