The exposureReplacement cost is the whole question here.
Westchester's high-value market is primary, not seasonal: these are houses families live in year-round. The risk is not that the standard market won't write them; it is that it will write them for less than it costs to rebuild them. Pre-war stone, slate, plaster, and millwork in Bronxville and Scarsdale carry replacement-cost gaps a price-shopped policy quietly leaves on the table.
The fix is a homeowners form built for the value: agreed value or extended/guaranteed replacement cost, a specialty or high-net-worth carrier where the file warrants it, with jewelry, art, and contents scheduled rather than sub-limited. Above that sits a single personal umbrella stacked over home, auto, and any watercraft, sized to the balance sheet the household actually carries.