How Long Does It Take to Build a Data Center? Timeline and Trades

A single large data center building usually takes about 12 to 18 months to build once construction starts, according to Virginia’s Joint Legislative Audit and Review Commission (JLARC, December 2024), and a full multi-building campus can take five years or more. The total time from picking a site to switching on servers is often longer, because land approvals, utility power and long-lead electrical equipment can take years before the first shovel goes in. For workers, that means a data center is not one job but a sequence of jobs, with different trades leading at each stage.

How long does it take to build a data center?

The honest answer depends on where you start the clock. JLARC’s study of Virginia, the biggest data center market in the U.S., found that construction of one building usually runs 12 to 18 months, with about 1,500 trade workers on site at peak. That is the stretch most electricians, pipefitters and ironworkers will experience.

The steps before construction can take much longer. Large sites need a utility connection, and in some markets that is the slowest part of the whole project. Bloomberg reported in August 2024 that Dominion Energy, the main utility in Northern Virginia, told customers that new data centers needing more than 100 MW could wait roughly four to seven years for a grid connection. A January 2026 Data Center Frontier summary of JLL’s 2026 global outlook said average interconnection timelines in many major markets now run beyond four years.

A few AI projects have moved much faster. Bisnow reported in September 2025 that xAI’s first Colossus site in Memphis went from start to running in 122 days, but it did so by converting an existing factory building rather than building from bare ground. The Stargate campus in Abilene, Texas, developed by Crusoe for Oracle and OpenAI, broke ground in June 2024, and DatacenterDynamics reported two buildings with more than 200 MW of IT load were live by October 2025, roughly 16 months later.

The phases of a data center build

Every project is different, but most follow the same order. Phases overlap heavily: crews are often setting equipment in one data hall while another hall is still being framed. Where we found a sourced duration, it is listed; otherwise the timing varies too much by project to give a fair number.

Phase	What happens	Main trades and roles	Typical duration (if sourced)
Site selection and land	Owner finds land with power, fiber, water and road access; due diligence and purchase	Real estate, civil and electrical engineers, surveyors, environmental consultants	Varies widely
Zoning and permits	Rezoning, site plan approval, building, environmental and air permits (for generators)	Land use attorneys, permitting specialists, design engineers	Varies by county or province
Utility power and substation	Utility studies the load, builds or upgrades transmission lines and a substation	Utility lineworkers, substation electricians, high-voltage engineers	4 to 7 years for 100+ MW in Dominion territory (Bloomberg, Aug. 2024)
Site work and foundations	Clearing, grading, utilities underground, duct banks, footings and slabs	Equipment operators, laborers, concrete finishers, pipelayers	Part of the 12 to 18 month build (JLARC)
Structure and shell	Steel or precast concrete frame, walls, roof, dry-in	Ironworkers, carpenters, roofers, crane operators	Part of the 12 to 18 month build
MEP rough-in	Conduit, cable tray, busway, chilled water piping, ductwork, fire protection	Electricians, pipefitters, sheet metal workers, sprinkler fitters	Part of the 12 to 18 month build
Equipment setting	Switchgear, transformers, generators, UPS, batteries, chillers set and connected	Electricians, millwrights, riggers, pipefitters, vendor field technicians	Depends on equipment delivery
Data hall fit-out	Containment, overhead power, liquid cooling loops, fiber pathways, security systems	Electricians, low-voltage and fiber techs, pipefitters, controls techs	Part of the 12 to 18 month build
Commissioning (L1 to L5)	Equipment and systems tested alone, then together under load	Commissioning agents, controls/BMS techs, electricians, test and balance techs	Final weeks to months of the build
Turnover and operations	Owner’s operations team accepts the building; servers are installed	Critical facilities technicians, data center technicians, security	Ongoing for the life of the site
Phased expansion	Next building or data hall on the same campus	Same construction trades return	Full campus: five or more years (JLARC)

Before construction: land, permits and power

Most of the early work happens in offices, not on site. Owners look for land that already has, or can get, large amounts of power, fiber routes and water. JLARC noted that developers like to move fast once a site is chosen, and that sites with road and utility access can start construction soon after selection.

Power is the long pole. A large campus may need its own substation and new transmission lines, built by the utility or by contractors working for it. This is where utility lineworkers and substation electricians come in, often years before the building trades arrive. If you want to work on the front end of these projects, utility and substation contractors are worth watching.

Local approvals matter too. As of September 2024, JLARC counted at least 70 new data center sites under active development in Virginia, and some were still waiting on local rezoning. Generator air permits, stormwater plans and noise rules can all affect the schedule.

Site work, shell and MEP rough-in

Once permits are in hand, earthwork crews clear and grade the site and install underground utilities and electrical duct banks. Concrete crews pour footings and slabs. Then the structure goes up, usually steel or precast concrete, followed by the roof and walls so the inside can be worked year-round.

MEP rough-in is where data centers differ most from ordinary commercial buildings. The building is mostly an electrical and mechanical plant, so electricians and pipefitters make up a large share of the workforce. Microsoft’s description of its Mount Pleasant, Wisconsin AI campus (September 2025) lists electricians, plumbers and pipefitters, carpenters, structural iron and steel workers, concrete workers and earth movers among the more than 3,000 construction workers at daily peak.

Long-lead equipment: why transformers set the schedule

The big electrical gear is built to order, and it often takes longer to arrive than the building takes to put up. Wood Mackenzie’s lead-time survey, published with American Clean Power in September 2025, found that in the second quarter of 2025:

• Power transformers averaged about 128 weeks from order, or roughly two and a half years.
• Generator step-up transformers averaged about 143 weeks.
• Switchgear averaged about 44 weeks.

Those figures cover the power sector broadly, not only data centers, but data centers buy the same equipment. Backup generators are also in high demand. In September 2026, Generac announced an $8 billion agreement to supply large backup generators for Amazon’s data centers, with initial deliveries planned for 2027 and 2028, a sign that big owners now lock in equipment years ahead.

Delays are common. In Uptime Institute’s supply chain survey (fielded September to October 2025, published December 2025), 45% of North American respondents said they had a capital project delayed in the past year, and equipment and manufacturing delays were the most cited cause. For workers, late equipment can mean schedule gaps, overtime pushes when it lands, or crews moved to another site in the meantime.

Equipment setting and data hall fit-out

When the gear arrives, riggers and crane crews set switchgear lineups, transformers, generators, UPS modules, battery systems and chillers. Electricians terminate medium-voltage and low-voltage feeders, and pipefitters connect chillers, pumps and cooling towers. Manufacturer field technicians often supervise start-up of their own equipment.

Inside the data halls, crews install hot or cold aisle containment, overhead busway, cable tray and fiber pathways. AI halls add a lot of pipe: Microsoft says more than 90% of its Wisconsin AI facility uses closed-loop liquid cooling, which brings pipefitters and mechanical techs right into the server space. Low-voltage and fiber technicians install structured cabling, security systems and the building’s monitoring network.

Commissioning: Level 1 to Level 5

Commissioning proves that everything works before real servers depend on it. Data center owners and contractors commonly describe it in five levels, though the exact names and boundaries vary by owner specification. Test equipment maker Hioki and construction software firm Archdesk both describe the levels in roughly this way:

1. Level 1, factory acceptance testing: major equipment such as switchgear, UPS units and generators is tested at the factory, often witnessed by the owner or commissioning agent.
2. Level 2, delivery and installation checks: equipment is inspected on arrival and after installation, before it is energized.
3. Level 3, pre-functional or start-up checks: each piece of equipment is started and checked on its own, including wiring, alarms and controls points.
4. Level 4, functional testing: each complete system, such as a UPS system or chilled water plant, is run through its operating modes.
5. Level 5, integrated systems testing (IST): all systems are tested together, usually with load banks standing in for servers, while crews simulate a utility outage and other failures to confirm power and cooling ride through.

Some specs also add a Level 0 for design review. Commissioning employs commissioning agents, controls and BMS technicians, electricians, and test and balance technicians. It is detail-heavy work with scripted tests and sign-offs, and it is a common path from the trades into higher-paying technical roles. Browse open commissioning and QA jobs.

Who runs the job: owners, general contractors and MEP subs

Three groups shape the work on a data center site:

• The owner is the hyperscaler, colocation company or developer paying for the building. Owners set design standards, buy much of the long-lead equipment directly, and staff the site with their own project managers and, later, operations teams.
• The general contractor manages the schedule, safety, site logistics and subcontractors. Building Design+Construction’s 2025 Giants 400 report listed firms such as HITT, Holder, DPR, Clayco, Turner, Whiting-Turner, Fortis, JE Dunn and Mortenson among the largest data center builders in the U.S.
• Specialty subcontractors, especially electrical and mechanical (MEP) contractors, employ most of the craft workers. If you are an electrician or pipefitter, your employer on a data center job is usually the electrical or mechanical sub, not the owner or GC.

Project managers, superintendents, schedulers, safety managers and quality managers work for all three. These roles are listed under construction and building trades and project and construction management on our board.

What this means for workers

How long a construction job lasts. A building runs about 12 to 18 months, but each trade’s time on site is shorter or longer depending on when it starts. Earthwork and concrete crews are early; electricians, pipefitters and commissioning staff stay to the end. On multi-building campuses, which JLARC says can take five or more years to finish, crews may roll from one building to the next for years.

Pay and apprenticeships. JLARC reported that in Northern Virginia, starting electricians earned about $24 an hour and journeymen about $56 an hour, and one electrical union’s apprenticeship classes grew from 300 to 500 apprentices. Overtime, travel and per diem vary by contractor and project.

When to look for operations roles. Operations teams are usually hired before turnover so they can learn the building during commissioning. If you are on a construction crew and want a permanent job, the commissioning phase is the time to ask about openings with the owner or its facilities contractor. The permanent team is far smaller than the construction crew, as we explain in how many people work at a data center.

The downsides. Data center sites often run long shifts and extended weeks to hit deadlines. Many projects are in rural or fast-growing areas, so travel and temporary housing are common. Security rules, badge checks and strict safety programs are standard, and schedules can change when equipment arrives late.

Next steps

If you work in the trades, data center construction is one of the largest sources of steady project work right now. Look at open data center jobs by location, and pay attention to which projects are moving into commissioning if your goal is a long-term operations role.