So, I know it's not a big deal, but it irritates the excrement out of me when my Sim kids go to the next room to climb through the freaking wall into the top bunk of their bunkbed. So, does anyone know of a mod that fixes this? Because really, I don't know how much longer I can maintain my sanity watching my kids do this. -.- Thanks guys.

Can Sims climb to the upper bed from both sides?

This reminds me of the bowling lane, Sims can watch a game from the other side of a wall.

These things are a bit annoying but can be avoided changing the layout (for lack of a better
word) of the room or, in your case, using a single-sided bunk bed - assuming it exists, I don't
remember - if you want to keep it leaned to a wall.

Well, as far as I know there's only a ladder on the room side of the bed. Not that it stops the kids from climbing through the wall. I've discovered if I don't let them autonomously go to bed when they're tired, walk them into the bedroom and then make them go to bed, they climb up the ladder properly. As for rearranging the room, that's not really an option. My Sims have a small house at the moment with 2 kids, a toddler and a baby. And since the cribs take up a lot of room and the Sims like to throw a temper tantrum that they can't get to the crib if something seems even an inch too close to it, the room pretty much has to stay the way it is. I'm considering using money to expand the rooms just enough to put a partition wall between the two rooms to put a stop to the ability to reach the bed through the wall. I was just hoping someone knew of a mod that would fix this issue so I didn't have to waste money I'm trying to save to get a three bedroom house for my Sims. XD

Hehe. I got curious and I tried. The two UL's bunk beds are climbable
from both sides and, in order to use the upper bed, Sims will ignore walls.

I see three options:
- You can put something on the other side of the wall to prevent routing;
- You can try to find a custom "single sided" bunk bed;
- I'm trying to make one myself, but don't hold your breath.

EDIT:
- you can also move the bed away from the wall a little (holding ALT),
this way Sims can't ignore the wall.

this is the only one working way which I ever found

Oh my, this was brutal. The bed kicked my ass. Badly. But eventually I think I tamed the beast.

This is far from an elegant solution, I simply removed the routing slots from
one side of the bed so the upper one can only by accessed from the other
side (the one where the ladder is on the right). The lower bed is still accessible
from both sides, since that has no issues with walls.

So if you absolutely want to keep the bunk-bed leaned to a wall, you can use this.
Otherwise it's better to use one of the other two solutions.

These 2 bed are new custom objects, not replacements. They use UL resources:
they won't work without that EP, so don't think bad of me, this is not piracy.
You'll recognize them from the cc icon and from the name/description that
uses the prefix "(SingleSided Version) ". I've used English strings for every
localization because it was too much work to edit them all manually.

Out of curiosity: what's the correct form? Single side or single sided? Maybe both?

You're great Arsil :D
Now if some of my irresponsible simfamily produce bunch of kids I won't get mad again

Thanks for all the work Arsil! However, since I don't have UL, this doesn't solve my issue. I'll just have to keep looking.

Oh man! You know what? Clone with the renumbering option the bed you want
with S3OC (you have to clone a MDLR, not an OBJD) and I'll tell you what to do.
EDIT: tell me the name of the object you cloned.

Put something on the other side of the wall.

Arsil... I have not idea what you're talking about. lol But, it's ok. I'll just deal while I continue my search. With a little persistence, I'm sure I can find what I need somewhere.