On a still evening along Loudoun County Parkway near Waxpool Road, residents can measure a data center from their driveway without a decibel meter. A News4 crew clocked the drone from a nearby CloudHQ facility at roughly 90 decibels, loud enough that rolling up the car windows barely helps. A few miles south in Sterling, homeowners near Vantage Data Centers' 18-acre Ashburn II campus on Glenn Drive got a rougher lesson in July 2026, when a power failure on the 16th forced the site's three buildings onto diesel backup generators. One resident told a local reporter the noise and fumes had become "a curse on our life here."
That is the part of Data Center Alley that shows up on a walk-through, not a spreadsheet. Here is the part that shows up on your tax bill: Loudoun County's real property tax rate for tax year 2026 sits at $0.805 per $100 of assessed value, the lowest it has been in a decade and meaningfully below Fairfax County's $1.1225 rate for the same fiscal year. Buyers comparing Ashburn to Fairfax on price per square foot alone are missing half the equation. The other half is a trade-off worth understanding before you write an offer near this industry, not after you close.
The rate cut nobody voted to reverse
Loudoun's board has lowered the real property tax rate every year for ten straight years, from $1.145 per $100 in 2016 down to today's $0.805. That is not a fluke of budget timing. Data centers now generate close to half of the county's property tax revenue, and the county's own data center FAQ puts the return at roughly $26 in tax revenue for every $1 spent on services to the industry. Part of the reason is assessed value: a data center pencils out at about $609 per square foot, close to triple the value of other commercial uses in the county.
A 2026 report prepared by Mangum Economics for the Northern Virginia Technology Council ran the counterfactual. Strip data center revenue out of Loudoun's budget and the residential real property rate would need to climb from $0.805 to about $1.537 per $100, a 91 percent increase, adding an estimated $5,800 a year to the tax bill on a median-valued home. Put plainly: the rate you see today isn't a marketing number. It's what a residential tax base looks like when it doesn't have to carry the whole county on its own.
What that gap actually costs on an Ashburn address
Run the two counties' base rates against Ashburn's own ZIP code medians and the dollar difference stops being abstract.
| Loudoun County rate | Fairfax County rate | |
|---|---|---|
| FY2026 real property tax rate | $0.805 / $100 assessed | $1.1225 / $100 assessed |
| Est. annual tax on a $719,000 home (Ashburn Village / Broadlands median) | about $5,789 | about $8,071 |
| Est. annual tax on a $796,000 home (Brambleton / One Loudoun median) | about $6,408 | about $8,935 |
That's a gap of roughly $2,300 to $2,500 a year on the county rate alone, before any special district add-ons Fairfax applies in service areas like Tysons or the Dulles Rail corridor. It is real money, and it is one of the few line items where Ashburn's higher home prices don't automatically mean higher carrying costs than a comparable Fairfax property.
The other side of the ledger
That revenue comes from an industry that Loudoun's own supervisors are now openly second-guessing. Board member Juli Briskman put it directly: "We've become addicted to the data centers for their tax revenues, but at what cost?" The county has already answered part of that question with policy. As of March 2025, Loudoun ended the practice of approving most data center projects by right in office-zoned parcels. New and expanded facilities now generally require conditional use permits or Special Exception review, with a second phase of the zoning rewrite still working out specific noise and setback standards.
The scale explains why the policy shifted. Loudoun now has more than 200 operating data centers with roughly 100 more somewhere in the pipeline. County officials point to the revenue those facilities generate, funding two new schools opened in recent years with a third under construction, along with fire and rescue expansion. Residents living closest to specific campuses point to the hum, the generator fumes, and in at least one case a proposed Dominion Energy transmission tower planned near a home. Both things are true in the same county, sometimes on the same street.
Why this changes how you should shop, not just what you should expect to pay
The tax rate is set countywide. The noise, the fumes, and the transmission line risk are not. A buyer evaluating two homes at the same price point in the same Ashburn ZIP code can end up with identical tax math and completely different day-to-day experiences, depending on which side of a data center campus the lot sits on. County-level averages, ZIP code medians, and even HOA reputations won't surface that difference. Only the specific parcel will.
That is worth building into due diligence for any home search that touches Data Center Alley, which now includes most of eastern Loudoun:
- Visit the specific lot at more than one time of day, including evening, when cooling loads and generator testing are more likely to run
- Ask whether Dominion Energy has any transmission line or substation project proposed within sight of the property
- Check for pending Special Exception or conditional use applications tied to nearby parcels before you write an offer, not after
- Ask directly whether the property or its HOA has been party to any noise complaints filed with the county's zoning enforcement office
- Recalculate the tax math for the specific home's assessed value using Loudoun's current $0.805 rate rather than a rounded estimate from a portal listing
The upside still holds, if you shop the parcel and not just the ZIP code
None of this cancels out what's working in Ashburn's favor. The Silver Line's Ashburn and Loudoun Gateway stations, open since November 2022, still put a direct rail line into the calculation for buyers weighing a Fairfax commute against a lower tax bill. The 103-acre Rivana at Innovation Station development, planned along the Metro corridor near Loudoun Gateway, is set to bring a walkable, transit-anchored mixed-use center to that stretch of the county over the next several years. And the county's own budget language is candid that the low rate depends on a revenue source it does not want to lean on forever, which is itself useful information for anyone weighing a long hold versus a shorter one.
Frequently asked questions
Does the tax discount apply evenly across every Ashburn neighborhood? The rate itself is countywide, so every Loudoun homeowner pays the same $0.805 per $100 of assessed value. The dollar savings scale with home value, which means a Brambleton or One Loudoun buyer at the higher end of Ashburn's ZIP code medians captures more raw savings than a buyer at a lower price point elsewhere in the county.
Will Loudoun's low tax rate hold? It has fallen every year for a decade, but the county's own budget FAQ acknowledges it cannot become overly dependent on a single revenue source, and board members have publicly questioned the trade-off. Treat the current rate as durable in the near term, not as a permanent fixture.
How do I find out if a specific address sits near an active or proposed data center? Loudoun County maintains a public data center standards and locations resource, and an agent can pull pending zoning cases tied to a specific parcel before you write an offer. Neither step takes long, and both are worth doing before, not after, you fall for a house.
If you're weighing an Ashburn address against a Fairfax or Prince William alternative, the math is rarely as simple as the sticker price on either side. Suzanne Ager works through that kind of parcel-level diligence with buyers across Loudoun County every week. Book an appointment to talk through a specific address before you write an offer.
