Evaluating station-area catchments in high-density public housing: exit-based and walking-sensitive price revaluation in Singapore’s downtown line stage 3 eastern corridor

Station-area planning often represents rail access as a uniform buffer, but in high-density public housing access is organized through specific exits, walking routes, and estate layouts. This study examines differential post-opening Housing & Development Board (HDB) resale-price revaluation around four residential Downtown Line Stage 3 stations in eastern Singapore. HDB blocks are assigned to official station exits and compared across 0–400 m and 400–800 m catchments relative to a farther 1200–2000 m within-corridor comparison band, with 800–1200 m retained as a buffer. The analysis combines fixed-effects estimates with pre-trend and placebo diagnostics, official OneMap walking-distance bands, station-context diagnostics, and an outside-corridor matched comparison. The estimates are interpreted as differential revaluation, not system-wide causal effects. The 0–400 m catchment remains the most consistent positive band. The 400–800 m band is weaker under Euclidean bands but becomes smaller, positive, and context-sensitive under walking-distance reassignment. The findings support exit-based, walking-sensitive, and station-specific catchment evaluation rather than uniform station buffers.