Lots can’t be bought furnished

Problem

I want to buy a existing house for my Sim but there’s no option to buy it furnished.

I want to rent an apartment but the furnishing is showing as §0 and I can’t rent it furnished.

Solution

Do the following steps to use the cheat console

Open the cheat console with ctl-shift-c
Enter the cheat you need in the entry box which appeared in the upper left corner of your screen.
Hit ENTER
Repeat steps 2 & 3 for every necessary cheat.
After entering all needed cheats, close the cheat console with ctl-shift-c

Another Sim was living in that house before and moved with the furniture. This causes the house to become empty.

If you saved the house to the Library/Gallery, you can just replace it from there. If you didn’t, you need to refurnish it.

To avoid this place the furniture you want to take with you into your household inventory before moving and then move without the furniture.

Your Sim doesn’t have enough money to buy the house furnished.

If your Sim doesn’t have enough money you can buy it unfurnished and furnish yourself, cheat yourself some money or use the cheat freerealestate on to buy the house for free.

The lot is still a crime scene

Visit the lot with your active Sim. This should reset the crime scene

The family that live in the house has died

Enter the lot in buy/build mode from the map and add something to the lot. The option to buy/rent it furnished should now appear. You will only need to pay for the one item you just added but everything will be there.