This study develops long-term, living-area-specific sales price indices for Seoul’s multi-family housing market across five policy-defined living-area zones (Central, Southeast, Northeast, Southwest, Northwest). Using 732,987 transaction records from 2006 to 2024 obtained from the Ministry of Land, Infrastructure and Transport’s disclosure system, the study employs a semi-log hedonic pricing model that controls for regional, locational, building, unit, and temporal attributes. The resulting indices reveal that the Central, Southeast, and Northwest zones’ indices recorded price growth exceeding the Seoul-wide index, whereas the Northeast and Southwest zones’ indices exhibited more moderate appreciation. In the aftermath of the late-2022 Jeonse fraud wave, all zones experienced a pronounced contraction in transactions and a corresponding stagnation of price indices. Relative to the Korea Real Estate Board’s index, our hedonic indices closely mirror actual transaction price movements and mitigate the excessive smoothing characteristic of traditional measures. By capturing submarket heterogeneity within living-area zones, these indices provide an empirical basis for spatially targeted housing policies—particularly for low-income and young adult households, who predominantly choose multi-family dwellings.