After finishing house there is a delay before allowing me to place a fireplace
After finishing the 2x2 house with a patio I tried to place a fireplace, but I was not allowed and it stated I have to be in my house to be allowed to place it.
Some minutes later I could place it when trying again.
Not sure if there is some odd delay in recognizing me to be in my house, but seemed to only impact the fireplace. I could place other furniture directly.