Quick answer
One is knocked over and gone; the other is still standing. The verse compares durability, and it means households rather than buildings.
Read both lines
"House" here carries its ordinary ancient weight, meaning a family and its line rather than a structure, so what stands is not property but people continuing. The first line is abrupt on purpose: overthrown, and then simply not there. Against that the second line offers nothing dramatic, only persistence, which is this book's usual way of recommending the slower thing. The claim is not that the righteous are spared trouble. It is that their household is still there afterward.
Related: Proverbs 12:3 · Proverbs 14:11 · Proverbs 10:25
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.