Cannot demolish empty house

I had this problem with an empty lot. It kept telling me I couldn’t demolish it while there were people or pets living there. While there were no Sims living there, there was a pet that I’d sent to the pet park years ago who originally lived in the lot I was trying to demolish. I went to the pet park and sent every pet there home. Then I went back to the area where my empty lot was and one pet showed up. I reassigned the pet to another household and then was able to demolish the house.