The only entity that can sue you for infringement is the patent holder. So you could send them an email and ask them whether they would sue if you sold your home.

"Commercial use" in the US typically means designing and operating a business around the idea. It would be up to a judge to decide. Here is a law cite:

http://definitions.uslegal.com/u/used-for-commercial-purpose...

The relevant language here would appear to be, "intended for profit." If you found yourself in a lawsuit, that's likely what judgment would hinge on.