Newmark Brokers 44,000 SF Lease at The Swig Company's Mills Building as Clay Expands in San Francisco

The Swig Company has signed a 44,000-square-foot office lease with Clay Development & Construction, an AI-powered go-to-market platform, at The Mills Building in San Francisco's North Financial District, the company announced July 29, 2026. Newmark represented both sides of the transaction.

Deal Details and Brokerage

Clay, which provides sales and marketing teams with tools to enrich customer data, automate prospective research, and personalize outreach at scale, will occupy 44,000 square feet at The Mills Building at 220 Montgomery Street. Bart O'Connor, Mark Geisreiter, and Hannah Potter of Newmark represented The Swig Company in the transaction. Maurice (Mo) Spikes, Derek Feinman, and Aaron Ellison of Newmark represented Clay. Financial terms of the lease were not disclosed.

"The Mills Building continues to attract companies seeking a workplace that reflects their culture and ambitions. Clay's lease is another example of an innovative business choosing downtown San Francisco to recruit talent, foster collaboration, and position themselves for long-term success. We're pleased to welcome Clay and look forward to supporting their continued growth," said Stacia Keisner, Senior Vice President of Asset Management at The Swig Company.

Spec Suite Initiative Surpasses 100,000 Square Feet Year to Date

The Clay lease contributes to The Swig Company's spec suite leasing activity at The Mills Building in 2026. The building has leased more than 102,000 square feet of spec suite space year to date, representing approximately 21 percent of the property.

"Through our focused spec suite initiative at the Mills Building, we have leased more than 102,000 square feet of space year to date, representing approximately 21% of the property. We are encouraged by this strong leasing momentum and expect it to continue throughout the remainder of the year and beyond," said Cory Kristoff, Executive Vice President and Director of Leasing at The Swig Company.

The pace of leasing reflects a broader pattern in the San Francisco office market, where amenity-rich, sustainability-certified buildings have drawn more consistent tenant interest than commodity office stock. U.S. office demand has continued to move toward stabilization in 2026, with annual demand turning positive after a prolonged period of occupancy losses, and vacancy has begun to ease modestly as absorption improves in higher-quality assets.

About The Mills Building

Built in 1891, The Mills Building is one of San Francisco's earliest steel-frame office structures and has been owned by The Swig Company since 1954. The building is also connected to an annex at 333 Montgomery Street. It offers onsite parking, a fitness center, a bike sanctuary with storage and maintenance facilities, shower rooms, and a flexible conference center with seating configurations ranging from 7 to 55 people. The Mills Building has held LEED Gold certification since 2012 and carries EPA Energy Star certification as well. Select tenant spaces within the building have achieved LEED Platinum and Fitwel 3-star certifications.

About The Swig Company

The Swig Company, LLC is a privately owned, San Francisco-based real estate operator founded in 1936 by Benjamin H. Swig. The firm operates a vertically integrated platform encompassing investment, asset management, property management, and leasing across commercial real estate properties in major U.S. markets. The company emphasizes long-term investment horizons and sustainable practices as core elements of its operating strategy.

Sources

The Swig Company – Press Release, July 29, 2026