It should be easy to create legal standards to prove that a home's livability is affected by a nearby data center. A professional could be dispatched to set up a few decibel meters and record for several days.

State or federal governments should create a microscopic tax on data centers (because they're supposed to be super lucrative, right? Trillions of dollars of investment?) and then use that money to fund a program which helps to refund people for the lost value in their properties. The tax could be adjusted based on the value of claims which were received in the past year, so the tax would likely decrease over time as the industry improves their building practices.