Skybox and Prologis file for fourth and largest Hutto data center

Skybox and Prologis filed this week with the Texas Department of Licensing and Regulation for Skybox Hutto 4, the fourth and largest building at their data center campus in Hutto, Williamson County, about 28 miles northeast of Austin. The application, reported by Data Center Dynamics, describes an 846,300 sq ft single-story core-and-shell structure at 3399 County Road 132 with a future use as a data center, a construction window running from January 2027 to October 2028, and a $550 million investment from Skybox.

Building 4 is the largest of the four filed so far: the first two Hutto buildings were each listed at 235,720 sq ft and the third at 492,350, making the new application about 72 percent larger than Hutto 3, bigger than Hutto 1 and Hutto 2 combined, and roughly 88 percent of the square footage of all three earlier phases. It is also the only single-story building in the sequence, whereas its predecessors are set to span two stories—a design difference that points to a larger land take per square foot of floor area without explaining why the developer moved to one level.

The site owner is listed as Hutto Data Center Campus, LLC, an affiliate sharing an address with Prologis, the real estate firm that has worked with Skybox since early 2021, when the two filed to convert an empty Prologis warehouse in Chicago into a data center.

Skybox filed for Hutto 1 in October 2023, then Hutto 2 in April 2024 and Hutto 3 in May 2024—three applications inside seven months for parcels along the same county road—followed by a gap of roughly two and a half years before this week's fourth. The coverage does not say what accounts for the pause, or whether the first three buildings are under construction or complete. Permitting, power procurement, and leasing each run on their own clock, and a licensing application does not say which one is binding, so the filing record alone is thin ground for reading the gap as evidence of demand in either direction.

Skybox and Prologis describe the site as part of PowerCampus, planned for 600MW of IT capacity across 3.88 million sq ft. Divided out, that plan implies about 155 watts of IT load for every square foot of the planned footprint, and the four buildings filed so far total roughly 1.81 million sq ft—a little under half the campus plan—which suggests more applications lie ahead if the build proceeds as drawn. Capacity rather than floor area will decide the outcome; grid access and load-class rules now set returns before a data center signs its first lease.

Hutto is filling in from more than one direction, with Iron Mountain and Colovore also developing sites in the town. Colovore arrives with a Texas program already running, including a $430 million liquid-cooled data center in Fort Worth filed in September. With four Skybox buildings and two competing developers in the same town, the permitting process has its own timetable, and consent is where the next phase's schedule gets set.

Skybox brings a Texas-weighted portfolio to Hutto, with projects in Austin, Dallas, Houston, and Wichita Falls, and the fourth filing extends a development bet that began with Hutto 1 three years ago. Prologis brings the land and the template that has carried the partnership across multiple projects; state licensing records show seven Prologis items, four of them transactions between mid-August and mid-September, and the Hutto arrangement—an affiliate holding the parcel, Skybox developing it—is likely a way for a logistics landlord to convert land into data center development at better than warehouse economics. The coverage does not describe the terms between the two firms.

$550 million against 846,300 sq ft works out to roughly $650 a square foot for a core-and-shell building whose fit-out, if any, the filing does not describe. The application is a construction and licensing step, and the coverage identifies no tenant for Hutto 4 and does not say whether one has signed, which leaves the building among the unanchored merchant shells—where assets with a named anchor tenant or a sovereign buyer get infrastructure pricing and unanchored shells wait for a counterparty to appear.

A fifth application within months would make the pause between Hutto 3 and Hutto 4 look like a scheduling artifact. A next filing that waits until Building 4 finishes in October 2028 would mean the campus is being metered out one shell at a time; the concrete date on the calendar is January 2027, when Skybox's construction window opens on the largest building the partners have filed for at Hutto.