solver

Still does not show for me.

You do have a railing that is causing the wall problem between the master tub and shower. Pull the 3 walls back and you wil be able to see and delete the railing.

Not there when I view the plan.

Can you select it? If so, it will show in the status bar what it is.

If this structure will be permitted, I would be discussing my ideas with the local code enforcement people. Finding out about stairs, room ceiling heights etc.

For showing the stairs in plan, and camera views, consider using a ladder. You will need to source one made in Sketchup, since bonus catalogs are not available for your version.

You have mentioned several times about wanting a well insulated structure, which prompted my suggestion of a foam outer layer. This is standard practice in many areas. 

You may google "balloon framing" and see images of how it's usually done.

I think you are over thinking/over engineering the structure. No need to reinvent standard practice.

Update us with your latest floor plan -- it's always interesting to see others ideas.

Why not build a second floor using standard wall framing?

Easy to place windows on any wall. Use all the floor space.

I've never understood the gambrel roof form on small spaces. 

Roofing is more expensive than siding.

2x6 floor joist need mid span support.

Balloon framed walls generally use a let in ledger to support the end of the joist, not sistered studs.

Wood is a poor insulator, and filling your wall cavities with additional wood will not help with insulation.

I'll suggest again a 2x4 wall with rigid foam on the exterior. This almost completely eliminates thermal bridging, and gives you a few more inches on the interior.

You could run XP in virtual mode -- essentially XP running within Windows 7,8 or 10.

You could dual boot. Have both operating systems installed and choose one at system startup.

http://www.amazon.com/Chief-Architect-Home-Designer-Download/dp/B0044DE8K2/ref=sr_1_26?ie=UTF8&qid=1439408455&sr=8-26&keywords=Chief+Architect

Why are you stuck on XP? Have you considered Windows 10? It's supposed to run on lower spec hardware better than 7 or 8.

View > Toolbars

or reinstall.

I'd be considering a single floor design as well. This one is 374 sq ft, and provides reasonably sized kitchen and bath. 

Back to 256 sq ft, but not 16x16. Minimal kitchen, but full bath down. Roof ridge could run either was as shown in the last image.

This type of question is often easily and quickly answered with a Google search.

Try "kitchen bartop overhang".

Here is the larger version, same lower floor, simpler roof. Needs full bath downstairs.

I did a bunch of roofs for this one, including what you suggested. I was going for the small house that had been added on to several times look.

At some point, it must make sense to do a full 2nd floor, or not?

This plan seems like you could live there full time, where the 16x16 plans seem like space for a weekend or week.

That makes sense. Roofs and walls are tied together in several ways.

Posting the xxx.plan file will help us help you. Make sure it's not open in Home Designer when you post.

This one is larger. Started out as a way of putting the stair outside the main area and evolved back to a square.

Plenty of room upstairs for a full bath. 

Inverted Wedge is the shape you want. I knew about that, and even placed one in plan, but failed to see how it resized. 

Taking a second look, now I do. You vary the shape by dragging a side, not the corner.

I always learn something from doing it the hard way, anyway.

Discovered this awhile ago, and kept forgetting to share.

Sometimes you will have gaps, especially where you have manually dragged a wall up or down. 

Setting one or more walls as Attic Walls seems to heal gaps.

This works for interior and exterior walls.

Setting the triangle shaped wall to Attic Wall, results in the second image.

Like the spiral stair. Space saving.

If you have the floorspace, like a 2 car garage, consider using tape to layout a plan or two. Ideally a bit of furniture and cardboard for cabinets will give you an idea of space.

Older homes often started with an outhouse, then added on a bathroom. Having a downstairs bath outside the 16x16 space would free up some floor area, and give the exterior a bit more character.

2x4 construction with exterior foam will give you a few extra inches inside, and a well enough insulated wall.

So much work for something so simple   Someone please tell us how easy this is.

I'm sure there MUST be an easier way. I have attached the plan file so you can have a look for yourself.

I did not do things in this order, so if something does not work, try again.

1) Extend the stair wall out so that it will cover the gap. Place a break at the corner where you extended the wall from.

2) Change the new wall (create a new wall type) to be solid paper. One layer, paper, 4.5" thick. Set it to Attic Wall. Realign with the stair wall.

3) In an elevation view, select the wall and drag it up forming a triangle.

4) Draw a Ceiling Plane at the same angle as the stair, covering the bottom of the exposed stair. You will need to lower it. Drag it over to cover the bottom of the triangle.

5) In a camera view, paint the new wall drywall so it blends in. Play with everything to get it looking correct.

Setting to Attic Wall for some reason makes the program heal the walls -- try it with and without that setting.

Making the new wall solid paper (other materials may work) lets the ceiling plane extend to its edge. If the new wall is drywall, the ceiling plane stops 1/2" shy, creating a visual problem.

Stair Cover Up.plan

Structural ridge. Glulam, PSL, LSL, solid, built up.

How the roof is tied into the porch roofs may also impact this issue.

Open Help and search "joist direction". This should get you going on that issue.

As for the wall. You could turn off the display of Attic Walls, and if you uncheck Invisible on the ones you changed, they won't show either,

Of course, this turns of all Attic Walls, so the Attic level will be blank.

This will not turn them off in 3D views.

Good ideas and plan Jo Ann.

Here is my twist on your idea.

Welcome Pat.

It would help me (us) if you were a bit more specific about a few things.

you will see that there is a shed (skillion) roof on the east and another on west side. I manually drew the roofs and auto walls were generated above the existing wall: they then show up on the floor 2 plan.

East and West are not shown on your plan, so you might use right/left/top/bottom as viewing on screen.

What existing wall were the auto walls generated above? 

Using a program that lets you write/circle things etc on an image often conveys more information than a written description. Paint on a PC is one program, but far from the best.

One of my early frustrations with the software was having to tap the spacebar to exit from whatever mode I was in. So much can be done with the mouse only.

I upgraded to a mouse with programmable buttons and set one to send a spacebar keystroke. Problem solved.