Colocation in Ashburn and Northern Virginia: what the market word hides

First, the geography problem#

"Ashburn" functions in this market the way "Silicon Valley" does — as a name for a region rather than a town. That is fine in conversation and expensive in procurement, because the buildings are in different jurisdictions with different power utilities, different tax treatment, different latency to the interconnection core, and materially different constraint profiles.

Below, every facility is labelled with the city it is actually in. Where a market guide says "Northern Virginia" it means the market; where it names a town it means the street. That distinction is the most useful thing this page does.

The operator landscape#

Verified against operator-published material as of 26 August 2026. Two conventions worth understanding before you read the tables.

Megawatt figures are missing for most of this market, and that absence is real rather than lazy. Digital Realty does not publish power figures for its facilities, and neither does CoreSite. Where you see a megawatt number below, an operator published it. Where you do not, none exists publicly — that is a genuine gap in the public record, not something we failed to look up.

Some operators appear as one grouped row covering several of their own site codes. Where the public record names a run of codes but never resolves them to individual buildings, we carry them as one row rather than asserting buildings nobody has confirmed. This under-counts those operators on purpose. Equinix's own documentation warns that several of its site codes can sit inside a single building, so a code is not a building for that operator.

Ashburn proper — Loudoun County's Data Center Alley#

Sterling and Dulles#

Reston — where CoreSite actually is#

Manassas — federal-grade, and a different market#

Iron Mountain's Northern Virginia estate is a 142-acre campus in Manassas, in Prince William County. It is roughly thirty miles from Ashburn, on a different power market, and it is where the region's most distinctive compliance and physical security posture sits.

Herndon#

365 Data Centers operates a Herndon facility. The operator publishes no site-code scheme at all, so the metro name is the identifier. Two things to know: there is no native AWS Direct Connect, Azure ExpressRoute or Google Cloud Interconnect at any 365 facility — cloud access runs through an interconnection partner only. And 365's compliance attestations date to a 2015–16 audit cycle covering an estate it no longer owns, so ask for a current attestation before leading with compliance here.

What is deliberately not on this page#

Two exclusions worth stating, because a guide that silently omits is indistinguishable from one that never looked. A bare-metal and GPU compute site in Ashburn operated by phoenixNAP is not sold as colocation on that operator's own colocation page, though it has a precise address and is counted as a data center by aggregators — the clearest local example of a listing that survives an address-based ingest and is still not supply. And Expedient has no Ashburn building: its facilities page references peering relationships in Ashburn, which is not the same as operating there.

Network and cloud ecosystem#

This is the most interconnection-dense market in the world, and the practical consequence for a buyer is that carrier choice is rarely the constraint here. What does constrain you is which specific building you are in, because the campuses are spread across four towns and the distances are real.

Equinix's Ashburn campus is the largest single-metro Equinix presence in the Americas, and AWS Direct Connect is confirmed for Ashburn and Northern Virginia at metro level. Everything else in the Equinix portfolio story here — Azure ExpressRoute, Google Cloud, Oracle, IBM — is fabric-level marketing rather than a confirmed on-ramp in a named building.

On peering: CoreSite's Any2East public peering exchange and its Community IX, deployed February 2026, are campus-level rather than per-building facts. If your architecture depends on exchange access, confirm it for the specific building you are being quoted rather than the campus.

One market-specific caution: Iron Mountain's Manassas campus carries NIPR, SIPR, JWICS and N-Wave. These are federal network environments, not commercial cloud on-ramps, and conflating them is a costly misread on a federal-adjacent requirement.

Power and the Loudoun constraint#

Loudoun County is the most power- and interconnection-constrained data-center market in North America. That is the single fact that most shapes buying behaviour here, and it explains a great deal about the market's geography — why operators are announcing land in Ashburn while building capacity in Manassas, Sterling and further out.

For a buyer, the constraint expresses itself in three ways. Lead times on new capacity are long and dependent on utility interconnection rather than construction. Contiguous expansion adjacent to an existing deployment is genuinely scarce and should be negotiated at signature rather than assumed. And the submarkets outside Loudoun — Prince William County around Manassas, and the Dulles corridor — are where a meaningful share of the market's actual new delivery has gone.

This is also why the Ashburn-versus-Northern-Virginia distinction is commercial rather than pedantic. A requirement that genuinely needs Loudoun latency and Loudoun interconnection is a different requirement, in a different constraint environment, from one that needs Northern Virginia. If yours is the second, saying so widens your options substantially.

When Northern Virginia is the right metro — and when it is not#

It fits when#

• Interconnection density or peering breadth is genuinely the requirement. Nowhere else in the world offers this depth, and for content, network and peering-dependent architectures the market is close to non-substitutable.
• You need East Coast cloud proximity, particularly to the largest AWS region, with the option of a private connection rather than public internet.
• Your requirement is federal or federal-adjacent. The Manassas campus's SCIF space, cleared staff and federal network environments are unusual anywhere and concentrated here.
• You need very large contiguous capacity and can engage wholesale operators directly — this market holds buildings above a million square feet.

It does not fit when#

• You are price-sensitive and do not need what this market is expensive for. Northern Virginia prices reflect the world's deepest interconnection ecosystem. If you will not use it, you are paying for someone else's requirement.
• Your growth path needs significant new power in Loudoun specifically. See above — this is the market's binding constraint and it is unlikely to ease quickly.
• You need geographic diversity from an existing East Coast footprint. A great deal of the eastern US already concentrates here; a second site in the same market is less diversification than it looks.
• Your requirement is a handful of cabinets and nothing more. You will be a small customer in a market built around very large ones, and a regional metro will usually compete harder for the business.

When the big brands are the right answer here#

In this market, more often than in most. Equinix's Ashburn campus genuinely is the answer when interconnection density is the buying criterion — it is the largest single-metro Equinix presence in the Americas, and no mid-tier operator substitutes for that ecosystem. Digital Realty is the right answer for scale, for very large contiguous requirements, and for buyers who need one contract across several metros. CoreSite's Reston campus is the right answer for a US multi-metro hybrid-cloud architecture, and VA3 specifically for anything where a confirmed 400G AWS on-ramp in the building is worth paying for.

The honest framing for Northern Virginia is not that the large operators are over-recommended — it is that they are recommended for the right reasons here and the wrong reasons elsewhere. The mistake this market punishes is different: it is shortlisting on the word "Ashburn" and never noticing that half your list is in other towns.

Pricing context for Northern Virginia#

As everywhere in colocation, no operator in this market publishes a rate card — pricing is quote-only and sales-engineer-gated across every operator in our corpus. We publish no per-operator figures for the reasons set out in how to run a colocation bid.

For orientation, CBRE's H2 2025 North American report put retail colocation asking rates at roughly $196 per kW per month for 250–500 kW deployments, with deployments above 10 MW up around 19%, against a record-low North American vacancy rate of 1.6%. Northern Virginia sits at the tight end of that picture rather than the loose end, and in this market the practical implication is that availability and delivery date frequently constrain a decision before price does.

Two market-specific commercial notes. Expansion rights are worth more here than almost anywhere, and are a term to negotiate at signature rather than a conversation to have later. And because the submarkets differ so much in constraint, quoting the same requirement in Ashburn, Sterling and Manassas can produce genuinely different answers on both price and date — which is an argument for specifying the market rather than the town when you go out to bid.

What this page deliberately does not tell you#

Who has space. Every figure above describes a building's size or the power it was built to carry, never what is unallocated — and in the most supply-constrained market in the world, that gap is the whole question. Availability here changes faster than anywhere, and no page can honestly hold it.

It is answerable only by asking each relevant operator, at the moment you need to know, against your actual requirement, and recording what they said and when. The sample reports show what those answers look like assembled into a comparison.