Hey there! I’m currently working on a 2 1/2-story building. I have finished up the hallways, but for the rooms, they feel empty to me, and I don’t know what to add to the rooms.
This is what it looks like currently:
Any suggestions would be appreciated. 
depends on what kind of building. add furnitures for a house, add desks for an office. you can also add paintings on the wall for decoration.
btw, the color of the building sucks, probably change that.
This building looks good so far! I recommend adding basic furniture, depending on what the theme/style of the interior will be. If it’s a normal house, then beds, shelves, nightstands, carpets, and desks/chairs. Nice job on the building so far!
