YOU CAN own a vacation house IN ANY WORLD in Sims 4, here's how you do it:
Find the house or lot you want for your vacation home. Go into it via Build Mode. In the top left (info panel) change the property to Retail. All you need on a retail property is one cash register. Buy one and place it on a counter. I hide my cash register by hitting the [ key to make it smaller. Then, with Ctrl-Shift-C I type testingcheats on, in the bar. Then I place another object over the tiny cash register so I don't have to see it.
After that, I go to the Sim family who wants a vacation home, they buy a retail place and NEVER OPEN it. They can go there any time. Friends and family can go with them or be called to visit.
One thing I have noticed is the stereos I have put in my vacation houses can only be designated to be put up for sale. If you want music for your Sims, you should put in the retail speaker(s) where you want.
If you need a non-cheating way to earn lots of Simoleons, without having a job, to buy the vacation home, place an Attic Stack Box next to a doorway so your Sim is standing in the doorway to Rummage for decorations. Have your Sim(s) Rummage until the floor is covered with decor. Then, go into Build Mode and sell all of it. There will be decorations in your Build Mode inventory, and you can sell them, too. Keep doing this until you have whatever amount of money you want.
Happy Simming!
I am, therefore I Sim.
