For a single-home household, Korea's long-term holding deduction adds 4% per year of ownership to 4% per year of residence, capped at 80%. Miss the three-year holding or two-year residence test and only a 2%-per-year general deduction remains.
On a 1bn-won home with a 400m jeonse deposit, 600m is gift-taxed and 400m capital-gains-taxed. Without the multi-home surcharge it saves 45.75m won; with it, it costs 38.71m more.
Acquiring a completed home through an ipjugwon (redevelopment membership right) carries a flat 2.8% acquisition tax regardless of how many homes you own. The same home via a bunyangkwon can reach 8%.
A single-home household is exempt with 2 years of ownership (2 years of residence in regulated areas) and a sale price under 1.2 billion won. Here is the apportionment formula for the excess and the 80% long-term deduction, worked through examples.