I was asked a while long, long, time ago to write up a tutorial about how I go about building split-level houses...
Then, a year later, another person gently reminded me that the first person had asked... so... I finally did it.
Sometimes it takes me a while. I'm sorry it took this long I hope this information is still useful?

This tutorial is presented through 30 pictures. They are numbered, and fairly self explanatory (I hope!) Please let me know if you have any questions.
The best piece of advice I can give you is: know where the undo button is, and make it your friend!
Experiment, be creative, hit "undo" a zillion times, and have fun


Things you will need before we get started:
- Numenor's Unlevel Wall - #90 - this is a "Must!" for split-level houses!
- tBudgett's Retaining Wall - another terrific split-level tool
- Life Stories Build Bundle - It's the second link in the top post - extracted by Argon @ MATY. This Maxis-made collection of wallpapers and floors are superb, especially for split-level construction.

And, you may also want:
Psychosim's Default Wall with Scale


Without further ado ~ here is how I build a basic split-level house...




























































How did you do? Don't give up!
You can download this house (and reverse engineer it any way you want to!) from my profile here on MTS.
Thank you for thinkin' with me ~ I hope this info useful for someone

Oh I'm so excited to try this out!!! Thank you so much @CatherineTCJ!! I will share pictures in the gallery when I've done it! This is wonderful though - I'm always such a fan of your building skills and this is no exception!!

Please let me know if you run into any problems.
Remember, this is the 'basic' technique - it can be configured in different ways. Just remember to "mind the gap"
Have fun experimenting!

I would love an advanced version of this tutorial using the GridAdjuster! :-) For example, like in many of your builds, an entrance at a 4-click level with stairs leading up to the main living space, and stairs leading down to a no-slope basement. (As seen in this build.)

Hi Nisse,
Combine the above tute with this one: Using Grid-Adjuster for No-Slope Basements and 1-Click/2-Click Foundations.

BUT - build the split-level on a foundation (you must have a foundation layer to make a no-slope basement) and keep the ground level. It will look 'wrong' until after you Grid-Adjust it. Don't get confused by the 'foundation' level. You have to think like it's not there. So - the front door section/level will need to be CFE'd to 4-clicks so that your shell looks like the house above (in this tutorial.)

Once you get the walls/shell in place - and each level is where you want it - so it looks like the house above, WITH a foundation under it...

Then - you'll want to set the grid adjuster to no-slope the basement at -4. (Follow the other tutorial for 'counting' instructions.)
Which will give you 4 steps to the front door, and a split with 8 steps down to the lower level and 8 steps up to the upper level.

Play around with it a bit - and ask questions I'm happy to help!
I will try to get a step-by-step tutorial written, but it will take me a while to get it done.

You're very sweet. Thank you!! It's funny how I didn't think to combine the tutorials ? Perhaps I just need to fiddle around more with GridAdjuster as to better understand how to combine different elevations.

Have fun with it!
Remember CFE'ing after using the Grid-Adjuster can undo things. But, the undo arrow is your friend! And, don't forget to hit the GA's 'versioned back ups' button.
Also - I usually just do the floors ( level 1, level 2, etc) as opposed to rooms (level 0-1, level 1-2) - I find "ranges" confusing. It's easier for me to think of it floor-by-floor.
Good Luck!