Loudoun County did not raise its real property tax rate for 2026. It stayed at $0.805 per $100 of assessed value. The county still estimates that the average homeowner's real estate tax bill rose $141 in tax year 2026, partly because home values went up. For anyone comparing an Ashburn home with one across the line in Fairfax County, that one sentence holds the whole story. The bill depends on the county's assessment of the house and on how much tax revenue the county collects from data centers.
Ashburn's low rate is real. It is also supported by a revenue stream that the county's own budget staff have asked the Board of Supervisors to shrink.
The bill moved because the assessment moved
The county's FY2027 budget announcement says plainly that a flat rate does not mean a flat bill. In the county's words, the average homeowner's tax "will increase by $141 in tax year 2026 due, in part, to an increase in home values." In the same release, the county says a cut to the vehicle personal property tax more than offsets that increase for the average homeowner who owns vehicles. Its example is a car assessed at $30,000, whose tax bill drops by $352 in tax year 2026.
The vehicle rate is $3.09 per $100 for tax year 2026, with a planned drop to $2.94 for tax year 2027. In Loudoun, the household tax picture therefore lives on two separate bills. Looking only at the real estate side misses half of the county's offset.
Assessments drive the real estate half. The county's 2026 real estate assessment presentation, dated February 3, 2026, shows these year-over-year revaluations:
| Property type, January 2026 reassessment | Revaluation |
|---|---|
| Single-family, developed areas with public water and sewer | 1.49% |
| Townhouses | 0.63% |
| Condominiums | -0.73% |
| Single-family up to 20 acres without public water and/or sewer | 3.70% |
In the same presentation, the average assessed value of a single-family home rose from $983,625 in 2025 to $1,002,702 in 2026. The Loudoun Times-Mirror's assessment coverage also put the 2026 average above $1 million, with slightly different percentages, such as 1.42% for the developed-area single-family category. The county's own figures are the ones used here.
How the change splits by property type affects a comparison. In the January 2026 reassessment, a condo owner's assessment dipped while a detached-home owner's rose. Both pay the same $0.805 base rate, which applies uniformly to all real property in the county.
Why the rate can sit that low
Loudoun's rate has been going down. For tax year 2024 it was $0.865, and it fell six cents to $0.805 starting January 1, 2025. According to Loudoun Now, 80.5 cents is the lowest rate in the region and 35 cents below Fairfax County's $1.155.
Here is a rough sense of that gap, offered only as arithmetic and not as a bill estimate for any specific home. Loudoun's 2026 average single-family assessment of $1,002,702 taxed at $0.805 comes to about $8,072 a year. The same figure taxed at $1.155 comes to about $11,581. Fairfax assessments follow their own values, so this only illustrates the scale of the rate difference, not what a Fairfax house costs to own.
The difference comes mostly from data centers. The county's FY2027 adopted General Fund revenue document forecasts two separate lines:
| FY2027 adopted forecast | Amount |
|---|---|
| Data center real property taxes, covering land and buildings | $417.7 million |
| Data center computer equipment taxes, covering servers and hardware | $879.1 million |
| Combined | about $1.297 billion |
| Total local tax revenue | $2.907 billion |
Data centers therefore account for roughly 44.6% of forecast local tax revenue in FY2027. The Loudoun Times-Mirror describes the same thing as about 45%, or nearly $1.3 billion. County staff have also used a different denominator and put data centers at 38% of General Fund revenue. Each figure depends on what it is divided into, but all of them describe a very large share.
The servers matter more than the buildings. The general personal property rate, which applies to data center computer equipment, is $4.15 per $100 and stays there for tax years 2026 and 2027. The Times-Mirror reported that data centers supply about 80% of all personal property taxes in the county. Commissioner of the Revenue Bob Wertz described the sector as having diversified a tax base that was historically residential-heavy.
Data center growth has also been pushing up the commercial side of the assessment roll. According to the county's February 2026 proposed-budget release, commercial property value rose 30.5% during 2025, mostly because of data centers. That added $13 billion and brought the commercial portfolio to $52 billion. The county said this growth reduces pressure on the residential tax base.
The county's budget staff want that revenue to shrink
This is where Ashburn differs from a typical low-tax suburb. Loudoun's budget office has said that the equipment tax supporting the low residential rate is too big.
In a FY2027 budget outlook briefing reported by Loudoun Now, staff said data centers then generated 38% of General Fund revenue. They warned that the share could exceed 60% within five to seven years if the $4.15 rate is not lowered. The staff report quoted by the outlet was direct about residential rates:
"Continuing to lower this rate, while at the same time keeping the general personal property tax rate the same, will further widen this gap and create significant challenges in the future when data center revenue stabilizes."
Management and Budget Director Megan Bourke explained the reasoning in the same article. "You cannot do that while continuing to collect the substantial amount of revenue that's coming from data centers," she said of the Board's goal of slowing budget growth. "If you continue to collect that revenue, you have to spend it."
The Board adopted the FY2027 budget on April 7, 2026. It kept both the $0.805 real property rate and the $4.15 equipment rate. The staff recommendation to cut the equipment rate was not adopted, and staff had also advised against further residential cuts. Those positions stayed on the table going into the next budget cycle.
That cycle has started. At the Finance Committee's July 14 meeting, as the Loudoun Times-Mirror reported, staff set an 8% growth target for FY2028 county and school budgets, with plans to step down to 5% by FY2031. Staff expected data center revenue to level off eventually. They also listed risks that included recession, federal cuts, tariffs, and a new statewide tax on data center power consumption. Supervisor Laura TeKrony suggested raising the equipment rate from $4.15 to $4.50 to eliminate the vehicle tax. Finance Chair Juli Briskman said that would distort the revenue balance but supported considering more car-tax reductions. That July discussion did not include a proposal to change the residential real property rate for tax year 2027.
Land use is now part of the tax picture
In Loudoun, how fast new data centers get approved feeds directly into future revenue, and that pace is changing.
- March 18, 2025. Supervisors ended by-right approvals for new data centers. New projects now go through the Special Exception process with a Board vote. Applications received by February 12, 2025, were grandfathered.
- Start of 2026. The Times-Mirror counted more than 200 data centers operating and more than 40 under construction. The slowdown it described was in expected revenue growth, not in construction.
- September 15, 2026. The Board voted 7-1-1 to have staff prepare a resolution pausing final action on legislative data center and substation applications for up to 12 months. Applications can still move through the Planning Commission during the pause, and administrative applications are not affected.
- October 6, 2026. The Board tabled a proposal to undo grandfathering. Staff said the 15 grandfathered applications cover 30 buildings and warned that litigation could cost $45 million to $60 million.
- October 20, 2026. According to the county's notice, the Board will consider the formal pause resolution, which it intends to make retroactive to September 15. Supervisor Briskman's office issued a statement describing the pause as already in effect.
- Summer 2027. The county expects to finish its Comprehensive Plan and Zoning Ordinance amendments on data center standards and locations.
Power capacity is the other factor. The county's FY2027 proposed budget expected strong growth in equipment tax revenue in part because the Eastern Loudoun transmission constraint was lifted in late 2025. Dominion Energy's Northern Virginia project page lists the Mars–Wishing Star line as expected to be energized by summer 2026. The State Corporation Commission approved Route 3A for the Golden–Mars line in a June 29, 2026 final order.
All of this explains why an Ashburn buyer's tax picture depends on more than the posted rate. The rate is a choice the Board makes each spring. Each year's choice is shaped by how much equipment tax is expected, and that depends on zoning votes, grid capacity, and whether the Board eventually lowers the $4.15 rate as staff recommend.
Questions buyers ask
Does Ashburn have its own real property tax rate?
No. The county applies its $0.805 per $100 base rate uniformly to all real property. Properties inside a special tax district pay an additional levy on top of it, according to the same budget document. Two Ashburn homes outside any such district differ in county real estate tax only by assessed value. When a home sits inside a district, the district levy belongs in the comparison too.
Has the county proposed changing the rate for 2027?
The FY2027 adopted documents set $0.805 for tax year 2026. The July 2026 Finance Committee coverage reported no proposal to change the residential rate for tax year 2027, and the formal FY2028 budget process is still ahead.
Does the data center pause stop construction already underway?
The proposed pause applies to final Board votes on legislative applications. Administrative applications are not covered, and the pause would not make any application inactive.
If you're weighing an Ashburn home against one in Fairfax or McLean, the Property Collective team can look up both properties' assessment histories and show how the figures in this post apply to each one. Schedule a Call.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
