If you are making the argument for resale purposes, having an RV parking pad is likely to hurt the resale value in the real world. Most home buyers do not have RVs. They want lawn and landscaping, not a big hunk of concrete beside their home. The value of the home is till going to be determined by location and condition. In your example, does the home without the pad have zoning restrictions? If so, by definition the homes do not have equal locations. If a pad could be installed, the value added to the other home would, at most, be the cost of installing a pad, and probably a lot less since the existing pad would almost assuredly not be exactly what the new owner would build since his building options are limitless. Your value exercise might be a good way to decide if you want to build a pad or not, but it doesn't directly correlate to purchasing.
