Anthropic Expands San Francisco HQ with New 505 Howard Lease

What happened

Anthropic, a leading artificial intelligence company, has agreed to lease about 100,000 square feet of office space at 505 Howard Street in San Francisco’s SoMa neighborhood. This expansion adds to its existing headquarters across the street at 500 Howard Street, where it subleased an entire 230,325-square-foot building from Slack in 2023. Both leases reportedly expire in 2028. The new lease at 505 Howard will occupy nearly a third of the 300,000-square-foot Foundry Square III building.

Why it matters

• Anthropic’s expansion signals growing demand for office space by AI companies in San Francisco, contributing to a potential revival of the city’s office market.
• The company’s move aims to create a campus-like environment near its headquarters, competing with AI rival OpenAI’s large Mission Bay campus.
• The AI sector is expected to bring more than 50,000 workers to San Francisco by 2030, significantly increasing office space utilization.

Key facts

1. 1. Anthropic leased approximately 100,000 square feet at 505 Howard Street, a 10-story building with over 300,000 square feet total.
2. 2. The company already occupies 230,325 square feet at 500 Howard Street, subleased from Slack in 2023.
3. 3. Both leases at 500 and 505 Howard Street are set to expire in 2028.
4. 4. The 505 Howard building houses tenants including KPMG and Intuit, both of which recently downsized their office space there.
5. 5. Anthropic raised $13 billion in Series F funding in 2025.

Key Voices

• Not stated in the article.