Pat and Mary Lou Hartness are excited about what’s about to happen to their home. But they aren’t sure they can stand to watch.

They gathered under a temporary canopy on their front lawn recently to unveil plans for what happens next to the house and rolling hills where they raised a family. Already underway is the 700-residence Hartness traditional neighborhood development nearby.

The next time workers take shovels and hammers to the property, they will start by causing…