Seoul H1 office vacancy rate rises to 4.9%

The CBD saw a total of 0.17m sqm of new space during the period.

Seoul's office vacancy rate rose to 4.9% in the first half of 2026 as a wave of large-scale CBD developments reached completion, although demand for existing Grade A buildings remained firm, according to Colliers' H1 2026 office market insights.

Vacancy increased 1.7 percentage points quarter on quarter as 0.17 million sq m of new office space was completed in the CBD, representing the highest level of supply since 2022.

Colliers said some of the newly completed buildings are expected to stabilise relatively quickly, with public-sector master leases already underway.

Excluding the latest completions, vacancy among existing Grade A assets changed only slightly from the previous quarter, indicating that underlying occupier demand remained resilient.

The figures suggest the rise in overall vacancy was driven primarily by new supply rather than a significant weakening in demand for established high-quality office stock.