Seoul's 'Sintong' housing plan adds only 87,000 units net, lawmaker says

Seoul Mayor Oh Se-hoon's "Sintong" fast-track urban planning initiative is unlikely to resolve the city's near-term housing supply crunch, a lawmaker said Tuesday. Because most units delivered through the program are expected to take at least seven to eight years to reach actual move-in, the ruling party argues that short-term supply measures are urgently needed.

According to a "2031 Housing Supply Plan" document that Oh Ki-hyung, a Democratic Party of Korea lawmaker on the National Assembly's Finance and Economy Planning Committee, obtained from the Seoul Metropolitan Government, the city is pursuing roughly 310,000 units of housing through the Sintong initiative by 2031 — but the actual net increase in Seoul's housing stock is estimated at only about 87,000 units.

An analysis of 253 Sintong project sites found that the areas currently contain a combined 222,126 units, while the planned unit count after redevelopment is 309,500. That means the projects would add a net 87,374 units — far fewer than the roughly 310,000 figure the city promotes. If the public interprets the "310,000 units" as entirely new housing added to Seoul's stock, the actual supply impact would fall significantly short of that impression, Oh said.

Particularly notable is that 30 of the 253 Sintong sites are projected to end up with fewer units than they currently have. One site in Yongsan-gu is set to shrink from 8,373 units to 5,970 — a loss of 2,403 — while a site in Seodaemun-gu would drop from 3,735 to 2,320, a reduction of 1,415 units.

The timing of supply poses an even greater concern. Breaking down the city's ground-breaking targets by year, the plan calls for 28,776 units to break ground in 2026, 24,142 in 2027 and 18,413 in 2028. Those numbers then surge to 53,505 in 2030 and 69,755 in 2031 — meaning 55.5% of all planned ground-breakings are concentrated in the final two years of Mayor Oh's term.

The Seoul Metropolitan Government assumes a roughly four-year gap between ground-breaking and completion. Under that timeline, units breaking ground in 2026 would be completed in 2030, those starting in 2027 in 2031, and those starting in 2031 not until 2035. Even if the plan proceeds on schedule, a large share of the units concentrated in the 2030–2031 ground-breaking surge would not be ready for move-in until 2034–2035.

The ruling party argues that while the Sintong figures represent the potential scale of future redevelopment, they fall short as a short-term supply remedy for the housing shortage Seoul could face as early as 2026.

"I agree with the overall direction of accelerating redevelopment and reconstruction to expand Seoul's housing supply," Oh said. "But what matters to residents is how many additional homes will actually be built, and when they can move in."

He added that of the roughly 310,000 units the city highlights, subtracting the existing 222,000-plus units leaves a net increase of only about 87,000. "With more than half of the ground-breaking plan pushed to 2030 and beyond, simply emphasizing the '310,000 units' figure cannot solve the supply problem that Seoul residents are actually feeling," he said.

Concerns about housing demolition also surfaced. Under the plan, existing homes totaling about 123,260 units — 53,505 in 2030 and 69,755 in 2031 — would be cleared for construction within just two years, triggering large-scale demolitions and resident relocations. If displacement demand becomes this concentrated in such a short window, it could destabilize Seoul's jeonse and monthly rent markets and push up housing costs.

Oh called on the city to go beyond simply announcing a ground-breaking target of 310,000 units and to promptly release a comprehensive relocation and rental stabilization plan — one that covers the scale of housing demolitions by year and by district, the number of households to be displaced and their relocation timeline, the volume of new move-ins and available jeonse and monthly rent supply in Seoul over the same period, a schedule for coordinating relocation timing across large project sites, absorption measures such as public rental and long-term jeonse housing, and a metropolitan-wide relocation strategy linked to housing supply across the greater Seoul area.