Does anyone know what that huge building is for between US 59 an

I believe POSTEL might be building a new facility

Superfantastik :
The steel/building people?

I think I just found my answer
The large building on E. Knox in Porter, TX between US‑59 and FM 494 is the Porter‑North Manufacturing Facility at 21769 E. Knox, a 315,649‑sq‑ft steel manufacturing plant owned by Postel International, Inc., scheduled for completion in December 2026.
What the Facility Is
It is a new steel manufacturing plant consisting of a pre‑engineered metal building with tilt‑wall wainscoting.
zabalist.com
zabalist.com
Total area: 315,649 sq ft, including a 303,276‑sq‑ft factory plus accessory structures.
Texas.gov
Texas.gov
Owner: Postel International, Inc.
Texas.gov
Texas.gov
Estimated project cost: $20 million.
zabalist.com
zabalist.com