Rice Real Estate Files $75M Research Building in Ion District

A $75 million construction project was registered with the Texas Department of Licensing and Regulation on Oct. 23, 2026, for a 200,000 sq ft office and research building at 4151 Main St. in Houston’s Ion District. The filing names the owner as Ion Houston LLC, an entity carrying Rice University’s own 6100 Main St. address, and lists Dallas-based HKS as the design firm. Rice Real Estate Company and Lincoln Property Company announced the building in 2025.

The building, known as The Arc, expands the Ion District that Rice has anchored in Midtown since the original Ion building opened on the former Sears department store site. The new structure sits on what was that store’s parking lot and will share a plaza with the 287,000 sq ft Ion, whose tenants already include Chevron, Microsoft, Saudi Aramco and BP.

Why it matters

For developers watching Midtown, the filing confirms Rice is moving past the Ion’s single-building footprint into a multi-building innovation district, with Lincoln Property Company brought in as a partner rather than Rice building it alone. The TDLR record puts a firm cost and timeline on a project that had so far only been described in announcements. The owner address on the filing ties Ion Houston LLC to Rice rather than a third-party buyer.

The numbers

The TDLR registration lists an estimated cost of $75.0 million for 200,000 sq ft of office and research space, with floor plates designed in the 28,000 to 31,000 sq ft range. Rice University is expected to anchor close to 30,000 sq ft of that space for energy, AI, data science, robotics and computational engineering research. Construction is registered to start Nov. 5, 2026, with completion set for March 15, 2028, a roughly 16-month build.

What’s next

The project is pursuing LEED Gold certification, and preleasing has already begun for the remaining space beyond Rice’s own footprint. The Nov. 5 start date is the next marker to watch; a City of Houston building permit for 4151 Main St. would confirm it. More on the metro’s pipeline is tracked on the Houston markets page.