Every agent has a request they hear more than any other. Mine, for the last few years, has been some version of this: “Amy, find us a newer single-story home in Summerlin West.” Downsizers ask for it. Empty nesters ask for it. Buyers coming from California ranch homes ask for it. And I have to tell them the truth, which is that one-story homes out here are scarce, and the good ones do not sit....