Clearly, one family won't be able to fit in a 1-bed, 1-bath shack. With 3 kids, they'll need at least 4 bedrooms and 2 baths. Include the grandparents on both sides, and that's 6 bedrooms, 4 baths. And for good measure, add a guest room with its own bathroom.

It makes perfect sense to reclassify a "single family home" as a 7-bed, 5-bath McMansion. Anything less is just a rental suite, obviously /s