A homeowner came to the registry today looking for a subdivision plan that shows his property. I helped him find it, and his deed. He pointed out how he has owned two lots, each 5000 square feet, for several decades, then went on to say that even though the current zoning ordinance calls for minimum lot size of 10,000 square feet, he still had two building lots because when he purchased them long ago, they complied with the zoning ordinance in effect at the time and so they were "grandfathered in."
I urged him to check with a lawyer about it and suggested among the things he discuss with the lawyer was something called "merger."
As I recall, the doctrine of merger, it holds that when two contiguous lots come under common ownership, they merge together to form a single lot. If this concept applied to zoning, his two "grandfathered lots" may have become a single complying lot when he gained ownership of the second of the lots.
I wasn't doing a good enough job of explaining what merger meant, so finally I asked "have you ever cooked pancakes?" He asked me to repeat the question at least twice before he decided that yes, I had asked him if he had cooked pancakes. "Yes, I've cooked pancakes." So I said, "If you have a smallish frying pan and drop in two scoops of batter intending to make two pancakes, but they spread out and connect together, you end up with one big pancake, not two little pancakes. That's the doctrine of merger." The guy smiled and said "I like that. Now I understand."
And now that my mind is fixated on pancakes, I might be stopping at the Owl Diner tomorrow for breakfast.