Artificial intelligence companies leased a combined 4.6 million square feet of office space in San Francisco and Manhattan during the first half of 2026, according to a report from CompStak and Savills. The activity is concentrated in a few neighborhoods and increasingly involves direct leases with longer commitments.
San Francisco accounted for 2.9 million square feet of AI leasing in the six-month period, more than in any previous full year tracked by the firms. AI tenants represented 31.3% of new leasing there, compared with 29.7% in 2020.
Manhattan recorded 1.7 million square feet of AI leasing, exceeding its combined total for 2024 and 2025. The sector’s share of new leasing rose to 8.2%, from 0.7% in 2020.
Availability has fallen sharply in areas favored by AI tenants. In Manhattan’s Park Avenue South submarket, it declined to 15.2% from 26.4% in the fourth quarter of 2023. In San Francisco’s Mission Bay and Showplace Square area, availability fell to 17.6% from 36.8%.
The leases also point to a shift in how AI companies occupy space. Subleases accounted for 23% of AI leasing volume in San Francisco during the first half, down from 44.9% over 2020–2024. Manhattan’s share fell to 17.9% from 42.3%. Average AI lease terms reached 90.9 months in Manhattan and 58.6 months in San Francisco, up from 49 and 46.3 months, respectively, in 2020.
The trend could benefit landlords with properties in the neighborhoods drawing AI tenants, including SL Green, Vornado Realty Trust, BXP and Hudson Pacific Properties. Its effect on each company will depend on where its available space is located and the rents and terms it can secure.