Got everything else but never heard of a downspout before. Or a downpipe. Though I guessed pipe. I guess I did hear the song about the itsy bitsy spider...
I don't think I've ever heard teardown used as a noun. You're asking for a house that will be demolished, so your answer is "A teardown". I don't believe teardown is a word that can be used in that way. Maybe change the clue to "To disassemble a house".
I should have got downsizing as I watch the Office. I love business euphamisms like that. Cleaning house is another colorful description of the same thing.
trying to tear down his reputation" still seems correct)