Owners' equivalent rent
Also called OER, rental equivalence.
How the CPI measures housing costs for homeowners: by the change in what it would cost to rent a comparable home.
The CPI doesn't use house prices for homeowners. It assumes the change in a homeowner's shelter cost equals the change in rent for a comparable property. Source 1
The price changes come from rents collected in BLS's housing survey, not from homeowners' estimates. Each rental unit is priced every six months. Source 1
Owners' equivalent rent makes up nearly a quarter of the CPI basket. Source 1 Source 2