I think The Sim Supply has a video on making them with what's in game and I'm not positive but I believe they worked? Could look and see I suppose. Its worth a shot.
Here are some sort of links on doing a fake L shape
https://www.youtube.com/watch?v=nNK3IxKXa2E
https://www.youtube.com/watch?v=YAYq7Kj2T78
https://www.youtube.com/watch?v=jKImG8WouOU
I didn't find James' at Sim Supply's version but I found his split level process:
split leveling https://www.youtube.com/watch?v=NOIuVFWh5DY