https://www.siliconvalley.com/2022/04/29/sellers-want-to-know-how-disclosing-problems-at-their-neighbors-home-will-affect-their-sale/

Q: We live in a Bay Area neighborhood where the value of the lots are now worth $2 million. It is time we sell and move. Custom-built houses are replacing family homes built in the 1950s at an alarming rate. The problem is our next-door neighbor. The owner, a retiree, has tall weeds growing in the side yard and backyard. To save money, he stopped the trash collection service. As a result, we have an odor and rodent problem. The front yard is in disrepair and the house paint is peeling. The owner has also deteriorated in appearance. We understand that selling a home with a bad neighbor will be costly. Will our house sell for 10% less or more? Do we have to disclose everything we know about this lousy neighbor? If so, the more we disclose, the more it will cost us.

A; It will cost you homebuyers — no question. It is hard to pinpoint the loss percentage, but it will be costly. Luckily, you are savvy enough to discuss the disclosure aspect of this bad neighbor. Good for you. Homebuyers appreciate full disclosure before writing an offer. Conversely, lack of disclosure is the most common claim homebuyers file against home sellers.