Seaholm Goes Musk: xAI Subleases 112,000 Sq Ft as the Tesla-SpaceX-Intel Terafab Joint Venture Takes Physical Shape

The downtown Seaholm Power Plant — where Elon Musk unveiled the $20 billion-plus Terafab chipmaking project last month — is becoming the physical home of the joint venture behind it. xAI has taken over Athenahealth’s entire 112,298-square-foot footprint at Seaholm through a sublease recorded in March. Commercial real estate firms suggest the lease is actually held by the full Tesla, SpaceX, xAI, and Intel consortium that is sponsoring Terafab.

What three CRE firms are independently saying

The deal surfaced through Q1 2026 Austin office market reporting from three commercial real estate firms operating in the city. CoStar’s data as of April 15 lists xAI as Athenahealth’s subtenant. Cushman & Wakefield, in its Q1 Austin office market report, also names xAI as the sublessee. CBRE goes further in its own Q1 report, citing the Terafab joint venture among xAI, SpaceX, Tesla, and Intel as the subtenant — Intel having joined the consortium only recently.

Jones Lang LaSalle, which represented Athenahealth on the sublease listing, identified the taker in its own Q1 report only as “an unnamed tech company” leasing precisely 112,298 square feet at Seaholm. xAI, Intel, Endeavor Real Estate Group (Seaholm’s landlord representative), Athenahealth, and JLL all either declined to comment or did not respond to requests.

Construction is already underway

On April 15, all public entrances to Seaholm were observed blocked off, with large “no photography” signs posted around the work zone. Tesla’s careers page has also begun listing a wave of engineering and management roles explicitly tied to Terafab, suggesting organizational ramp is underway in parallel with the physical fit-out.

Athenahealth, the Boston-based healthcare-tech company best known for its medical records platform, has leased the Seaholm space since 2014. Its decision to sublet the entire footprint opened the door.

What Terafab is, in Musk’s framing

At the March announcement event hosted inside Seaholm itself, Musk positioned Terafab as a project to produce one terawatt of compute annually — roughly 100 to 200 million AI chips per year. In his framing, the output would feed Tesla’s Full Self-Driving stack, the Optimus humanoid robot line, SpaceX’s launch vehicles, and ultimately the compute load required for a multi-planet civilization.

Seaholm is a bridge, not the destination

Musk has been explicit that Seaholm, and even the initial advanced-technology site he identified adjacent to Gigafactory Texas in east Travis County, are interim. A permanent Terafab fabrication site, he said at the March event, would require thousands of acres and vast power-generation capacity. The consortium is reportedly working with a local broker to scout candidate parcels.

xAI, Intel, Endeavor Real Estate Group, Athenahealth, and Jones Lang LaSalle either declined to comment or did not respond to inquiries.