Data center approvals in Loudoun County, Virginia
Updated October 2026
On March 18, 2025, the Loudoun County Board of Supervisors ended by-right data center development countywide. Every new data center now needs a special exception with public hearings before the Planning Commission and the Board. That change sits on top of a Dominion large-load queue running into the 2030s and a statewide generator rule that took effect July 1, 2026.
What the timeline looks like
| Step | Typical duration or status | What drives it |
|---|---|---|
| Special exception (zoning) | Legislative review with hearings at Planning Commission and Board of Supervisors; applications under review as of Feb 12, 2025 were grandfathered only if more than 500 feet from residential and unchanged | Loss of administrative approval; hearing calendars; opposition and conditions |
| Use-specific standards (Phase 2 of the county's review) | About 14 months projected from spring 2025 for standards on data centers, substations, microgrids and generators | Rules can change while an application is pending |
| Dominion large-load interconnection | Roughly 25 GW of large-load projects with energization dates assigned through 2031; new GS-5 rate class effective Jan 1, 2027 with 14-year contracts and reported collateral of about $1.5M per MW | Utility capacity, tariff terms, collateral |
| Air permit for generator fleet (Virginia DEQ) | 4 to 6 months synthetic minor; 6 to 12 months state major plus Title V; 1 to 2 years PSD. Applications filed on or after July 1, 2026 must meet Tier 4-equivalent emissions | Generator count, classification and controls chosen at design |
| Site plan, phased building permits, inspections | Standard county cycles; DEQ guidance limits what construction may start before the air permit issues | Sequencing of permits against the air permit |
| Long-lead electrical equipment | Power transformers about 128 weeks; generator step-up units over 160 weeks | Cannot be ordered safely until tariff, collateral and site control are firm |
Durations for air permits are consultant estimates for Virginia; Dominion figures are from the Virginia SCC and Virginia Mercury reporting in 2025 to 2026.
What slows projects here
- The special exception is a vote, not a review. It is won or lost on compatibility, noise, substation siting and generator impacts, which means the engineering has to be ahead of the application rather than behind it.
- A hearing-notice defect can void an approval years later: the Prince William Digital Gateway rezoning next door was voided in August 2025 over advertisements that did not comply with code, and the project was abandoned in April 2026.
- Time to power dominates everything else. Four-plus years to a grid connection in primary markets against an 18-month build, and a utility that will not finalize substation design until tariff terms and collateral are in place.
- The generator rule moved the air-permit question into site selection: Tier 4-equivalent units, the emergency versus non-emergency classification, and the permit pathway all change duration by months.
- Standards are still moving. The county's Phase 2 standards and the state's 2026 session (more than 60 data center bills introduced) mean the requirement set can change mid-application.
What to do about it
- Run the Dominion load study, the DEQ air permit and the special exception in parallel from day one; they are independent authorities and nothing requires them in sequence.
- Treat notice and hearing compliance as a checklist with evidence: advertisement content, timing, publication and parcel notification against state and county code.
- Lock generator count, size, tier and classification before filing anything, because a density change reopens the air permit, the noise study and the utility load letter together.
- Tie transformer and switchgear orders to approval confidence, not to the GC's schedule, and track factory slots against the energization date Dominion assigns.
- Model the GS-5 minimum bills and collateral in the pro forma before the special exception hearing, since the county will ask what the project costs the grid.
Plan this jurisdiction with the register already loaded
PowerPMIS's entitlement gate builds the full requirements register for one live project in two to three weeks, puts every hearing, review and utility step on your critical path, and lists what you can challenge. Fixed fee by project size.
Book a requirements auditSources
- Holland & Knight, Loudoun County eliminates by-right data center development (Apr 2025) — March 18, 2025 vote; grandfathering terms; Phase 2 timeline
- Loudoun County, Data centers: land use considerations
- Virginia SCC, Dominion biennial review order (Nov 2025) — GS-5 rate class
- Virginia Mercury, Review of Dominion's load forecasting (Apr 2026) — large-load queue through 2031
- Encino Environmental, Virginia data center generator emissions rule — July 1, 2026 Tier 4 cutoff
- Encino Environmental, Air permitting for data centers in Virginia — permit pathway durations
- Hunton, Virginia DEQ air permitting guidance for data centers — pre-permit construction limits
- Virginia Business, Prince William Digital Gateway officially dies (Apr 2026)
- JLL, Global Data Center Outlook 2026 — 18-month build; 4+ years to power
Timelines are general information drawn from the sources listed, not advice on a specific project. Rules change; confirm current requirements with the authority.