Key Takeaways
- • Seoul's overall office vacancy rate surged 2.3 percentage points quarter-over-quarter to 6.6% in Q2 2026, exceeding the natural vacancy threshold of 5% for the first time since Q1 2022, driven by full-scale new supply in the CBD.
- • CBD submarket vacancy rate jumped 5.4 percentage points to 12.3% as two major completions—G1 Seoul (1.53 million sq ft) and Rene Square (640,000 sq ft)—entered the market with entirely vacant space, signaling acute oversupply in prime Seoul office.
- • Net absorption in Seoul's Grade A office market recorded 166,000+ square feet in Q2 2026, indicating continued institutional and corporate demand despite rising vacancy, with recovery expected as pre-leased space achieves occupancy.
- • First-half 2026 office investment volume declined 17.7% year-over-year to KRW 12.3 trillion, reflecting investor caution amid supply uncertainty, though selective institutional activity continues in prime assets and non-CBD submarkets.
- • Market fundamentals suggest relief dependent on lease-up velocity; CBD oversupply concerns are temporary pending occupancy of pre-committed space, while non-CBD submarkets maintain relative stability with limited new supply expected before 2027.
Summary
Seoul's office market has entered a structural inflection point in Q2 2026, transitioning from a constrained supply environment to a period of full-scale new completions concentrated in the Central Business District. According to JLL Korea's "Seoul Class A Office Market Trends Q2 2026" report, the overall vacancy rate climbed 2.3 percentage points quarter-over-quarter to 6.6%—the first time the market has exceeded the natural equilibrium vacancy rate of 5% since Q1 2022. This marks a meaningful shift in market conditions for institutional investors after years of supply-constrained conditions that had supported valuations and rental growth.
The CBD submarket experienced the sharpest deterioration, with vacancy rates spiking 5.4 percentage points to 12.3% following the completion of two large trophy assets: G1 Seoul, comprising approximately 1.53 million square feet, and Rene Square, at approximately 640,000 square feet. Both buildings entered the market with their entire space in physically vacant status, concentrating immediate leasing risk in the prime CBD corridor. However, management and market observers note that these completions carry pre-leasing commitments, suggesting that the headline vacancy figures overstate operational stress. Once lease contracts achieve full occupancy, vacancy rates are expected to normalize downward materially.
Despite supply headwinds, Seoul's Grade A office market demonstrated measurable tenant demand, with net absorption exceeding 166,000 square feet in Q2 2026. This absorption activity reflects continued strategic engagement by institutional tenants and corporate occupiers, particularly in selective prime locations. Investment transaction activity, however, has contracted significantly; first-half 2026 office investment volume declined 17.7% year-over-year to KRW 12.3 trillion, signaling investor hesitancy as supply uncertainty temporarily depressed capital deployment in the sector.
The market's medium-term outlook hinges on lease-up velocity for recently completed space and the supply pipeline timing. With the GBD showing minimal new completions expected before 2027 and larger supply waves not anticipated until 2028–2029, the current oversupply concerns are likely cyclical and concentrated in the CBD. Selective institutional investors appear positioned to capitalize on temporary dislocation while maintaining conviction in Seoul's long-term office fundamentals, particularly in non-CBD submarkets where supply remains tighter and leasing conditions remain more stable.
The CBD submarket experienced the sharpest deterioration, with vacancy rates spiking 5.4 percentage points to 12.3% following the completion of two large trophy assets: G1 Seoul, comprising approximately 1.53 million square feet, and Rene Square, at approximately 640,000 square feet. Both buildings entered the market with their entire space in physically vacant status, concentrating immediate leasing risk in the prime CBD corridor. However, management and market observers note that these completions carry pre-leasing commitments, suggesting that the headline vacancy figures overstate operational stress. Once lease contracts achieve full occupancy, vacancy rates are expected to normalize downward materially.
Despite supply headwinds, Seoul's Grade A office market demonstrated measurable tenant demand, with net absorption exceeding 166,000 square feet in Q2 2026. This absorption activity reflects continued strategic engagement by institutional tenants and corporate occupiers, particularly in selective prime locations. Investment transaction activity, however, has contracted significantly; first-half 2026 office investment volume declined 17.7% year-over-year to KRW 12.3 trillion, signaling investor hesitancy as supply uncertainty temporarily depressed capital deployment in the sector.
The market's medium-term outlook hinges on lease-up velocity for recently completed space and the supply pipeline timing. With the GBD showing minimal new completions expected before 2027 and larger supply waves not anticipated until 2028–2029, the current oversupply concerns are likely cyclical and concentrated in the CBD. Selective institutional investors appear positioned to capitalize on temporary dislocation while maintaining conviction in Seoul's long-term office fundamentals, particularly in non-CBD submarkets where supply remains tighter and leasing conditions remain more stable.
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