Fairfax County vs Loudoun County Building Permit Fees (2026)
Side-by-side comparison using official fee schedule data from both Virginia counties. For an identical $15,000 deck: Fairfax County totals $504.00 (verified). Loudoun County totals $395.00 to $399.60, depending on whether the 2% state levy is added (see evidence quality notes below).
For a $15,000 deck addition (1,000 sq ft or less), Fairfax County charges $504.00 all-in (permit + 2% state levy + 10% county technology surcharge, Appendix Q FY2027). Loudoun County charges $395.00 to $399.60 all-in (the $395 bundle, plus the 2% state levy, if not already included, on its $230 building permit and plan review portion) - a difference of $104.40 to $109.00. Half of the Fairfax permit fee is due at application as a filing-fee deposit and is credited at issuance (County Code 61-1-3(d)11); it is not an extra charge. The Loudoun total is a range because Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2), but Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit). Loudoun's fee schedule is dated July 1, 2022 and is still the schedule the county links as of November 4, 2026.
- Loudoun County uses a bundled flat fee structure ($395 for small additions); Fairfax uses a percentage-of-cost formula (3% base) for decks and alterations, with a 2% levy and 10% technology surcharge on top.
- On low-to-mid-cost residential projects, Loudoun's flat fee tends to produce lower totals than Fairfax's percentage structure.
- For room additions, Fairfax prices by floor area under Appendix Q FY2027 ($0.15 per sq ft wood frame, $141.75 minimum): a 400 sq ft addition is $158.77 all-in, under Loudoun's $395.00 to $399.60 bundle. For additions over 1,000 sq ft Loudoun switches to 1% of construction cost plus a $335 plan review fee, while Fairfax stays area-based ($168.00 at 1,000 sq ft).
- The Fairfax total ($504.00) is verified against Appendix Q FY2027 (effective July 1, 2026). Half of the Fairfax permit fee is due at application as a filing-fee deposit and is credited at issuance (County Code 61-1-3(d)11); it is not an extra charge. The Loudoun total ($395.00 to $399.60) comes from the July 1, 2022 schedule, still the current published version as of November 4, 2026 - verify current rates before budgeting.
- Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2 (13VAC5-63-70); enabling statute Va. Code 36-137(7)). Fairfax shows it on its permit fee. Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit).
What Is Verified vs Estimated in This Comparison
This page does not present both totals as equally precise. Here is exactly what each figure is based on.
| Data Point | Fairfax County | Loudoun County |
|---|---|---|
| Fee schedule source |
Verified Official fee schedule, current |
Verified Official schedule eff. July 1, 2022, still the published version (re-verified Nov 4, 2026) |
| Base permit fee method |
Verified 3% of construction value, $141.75 min |
Verified $395 flat (additions ≤1,000 sq ft) |
| Plan review fee |
Verified 50% of permit fee collected at application as a deposit, credited at issuance |
Verified (bundled) Included in $395 flat - not broken out |
| USBC state levy (2%) |
Verified Applied to the building permit fee |
Not shown 2% of the $230 building permit and plan review portion if not already included ($0 to $4.60); never on the $165 zoning permit |
| Zoning permit |
N/A Not required in fee stack |
Bundled Included in $395 for small additions |
| $15,000 deck total | Verified: $504.00 | Range: $395.00 to $399.60 |
Fee Structure Comparison
Head-to-head comparison of the fee components each county applies to residential building permits.
| Fee Component | Fairfax County | Loudoun County |
|---|---|---|
| Fee calculation method | Percentage of construction value | Flat fee (small) or percentage (large) |
| Base permit fee - small project | 3% of cost · min $141.75 | $395 flat (≤1,000 sq ft additions) |
| Base permit fee - large project | 3% of cost (no upper cap published) | 1% of cost (>1,000 sq ft additions) |
| Plan review fee | 50% deposit at application, credited at issuance | Bundled in $395 (small) · $335 flat (large) |
| USBC state levy | 2% of permit fee | 2% of building permit + plan review if not already included (Loudoun does not say) |
| Zoning permit | Not part of building permit stack | Bundled in $395 (small) · Separate, cost unlisted (large) |
| Minimum fee | $141.75 | $65 |
| Fee schedule source | Current official fee schedule | Fee schedule eff. July 1, 2022, still current as of Nov 4, 2026 |
| $15,000 deck - all-in total | $504.00 Verified | $395.00 to $399.60 Levy range |
| Difference | $104.40 to $109.00 less in Loudoun Levy range | |
The difference is a range because Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2), but Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit). Loudoun's figures come from its fee schedule effective July 1, 2022, still the published version as of November 4, 2026; if Loudoun updates its fees, the difference may change. Verify with Loudoun County Building and Development at 703-777-0220 before using these numbers for project budgeting.
$15,000 Deck Addition: Line-by-Line Calculation
Same project, two counties, side-by-side arithmetic. Assumptions: deck is 1,000 sq ft or less (qualifies for Loudoun flat fee) and $15,000 in declared construction value.
$15,000 × 3% =
$450.00
$450 × 2% =
$9.00
$450 × 10% =
$45.00
$450 + $9.00 + $45.00 =
$504.00
Building permit + plan review + zoning =
$395.00
($100 building permit + $130 plan review) × 2% =
$0 to $4.60Note: the $395 bundle is $100 building permit + $130 plan review + $165 county zoning permit. The levy never applies to the zoning permit.
$395 + $0 to $4.60 =
$395.00 to $399.60
This total is based on Loudoun's fee schedule effective July 1, 2022, still the version the county publishes as of November 4, 2026. Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2), but Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit). Verify before budgeting.
| Line Item | Fairfax County | Loudoun County |
|---|---|---|
| Base permit fee | $450.00 (3% of $15,000) | $395.00 bundle ($100 permit + $130 plan review + $165 zoning) |
| County zoning permit | N/A | Included in $395 |
| USBC state levy (2%) | $9.00 | $0 to $4.60 (not shown) |
| Fairfax technology surcharge (10%) | $45.00 | N/A |
| All-in total | $504.00 Verified | $395.00 to $399.60 Levy range |
Why Fairfax and Loudoun Have Different Fee Structures
Both counties operate under Virginia's Uniform Statewide Building Code (USBC). Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2 (13VAC5-63-70); enabling statute Va. Code 36-137(7)), but it does not set the base permit fee rate. Each Virginia jurisdiction sets its own base fee method independently.
How Fairfax Sets Fees
Fairfax County uses a percentage-of-construction-value formula for decks, alterations and repairs: 3% of declared construction cost, with a $141.75 minimum (Appendix Q FY2027, effective July 1, 2026). The county adds a 10% technology surcharge alongside the 2% state levy on the permit fee - three components, 3.36% of value all-in. Half of the Fairfax permit fee is due at application as a filing-fee deposit and is credited at issuance (County Code 61-1-3(d)11); it is not an extra charge. This means the more a project costs, the higher the permit fee. A $15,000 deck pays $450 in permit fees; a $100,000 alteration pays $3,000 - plus levy and surcharge on top. Room additions, garages and new homes are priced per square foot instead ($0.15 wood frame).
Fairfax publishes its fee structure through Land Development Services, and the formula has been in effect and verifiable from their current published fee schedule.
How Loudoun Sets Fees
Loudoun County takes a different approach for smaller residential projects: a single bundled flat fee covers the building permit, plan review, and county zoning permit together. For additions of 1,000 sq ft or less, the published rate is $395.00 ($100 building permit + $130 plan review + $165 county zoning permit) - regardless of construction value within that size range. Virginia requires a 2% state levy on building-code permit fees (USBC Section 107.2), but Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit).
For larger additions (over 1,000 sq ft), Loudoun switches to a percentage formula: 1% of construction cost, plus a separate $335 plan review fee, plus a county zoning permit (cost listed as separate, not published in the fee schedule).
The bundled flat fee structure has a practical consequence: the published $395 does not say whether the state levy is included. The levy could apply only to the $230 building permit and plan review portion, never the $165 zoning permit, so the Loudoun total in this comparison is shown as a range ($395.00 to $399.60).
Why the Difference Is Largest on Mid-Cost Projects
On a $15,000 deck, Loudoun's flat $395 is significantly below Fairfax's 3% formula ($450 base), and Fairfax then adds the 2% levy and 10% technology surcharge for $504.00 all-in. The gap narrows as project costs fall. The all-in crossover is about $11,800 to $11,900 in construction value: Fairfax's 3.36% effective rate reaches Loudoun's $395.00 at roughly $11,756 and $399.60 at roughly $11,893. Below that threshold, Fairfax is lower (its all-in floor is $158.77 for any deck valued at or below $4,725). Above it, Loudoun is lower until the project crosses 1,000 sq ft and Loudoun shifts to its 1% formula.
Frequently Asked Questions
Is Loudoun County always cheaper than Fairfax for building permits?
For decks and other work Fairfax prices at 3% of value, Loudoun's $395 bundle ($395.00 to $399.60 depending on the state levy) produces a lower total than Fairfax's formula for projects above roughly $11,800 to $11,900 in construction value, where Fairfax's 3.36% all-in rate passes the Loudoun total. Below that threshold, Fairfax's $158.77 floor is lower. For room additions, Fairfax prices per square foot under Appendix Q FY2027 ($158.77 all-in up to 945 sq ft; $168.00 at 1,000 sq ft), which undercuts Loudoun's $395.00 to $399.60. For large projects over 1,000 sq ft, Loudoun's 1% formula applies and the comparison changes depending on zoning permit cost.
Is the $104.40 to $109.00 difference exact?
No. The $504.00 Fairfax total is verified from the FY2027 Appendix Q schedule (effective July 1, 2026, verified September 18, 2026). The Loudoun total of $395.00 to $399.60 is calculated from the fee schedule effective July 1, 2022, still the version Loudoun publishes as of November 4, 2026. It is a range because Loudoun's published fees do not say whether the required 2% state levy is already included; it can apply only to the $230 building permit and plan review portion. The actual difference also depends on whether Loudoun updates its schedule. Call Loudoun County Building and Development at 703-777-0220 to confirm current fees.
Does Loudoun charge a separate plan review fee?
For small additions (1,000 sq ft or less), no - the $130 plan review fee is bundled into the $395 published fee. For larger additions, a separate $335 plan review fee applies. Fairfax collects half of the permit fee at application as a plan review filing-fee deposit and credits it toward the permit fee at issuance (County Code 61-1-3(d)11), so it is not a separate charge.
Do both counties charge the Virginia USBC state levy?
Virginia requires a 2% state levy on building-code permit fees, collected by the local building department (USBC Section 107.2 (13VAC5-63-70); enabling statute Va. Code 36-137(7)). Fairfax shows it on the building permit fee (and adds its own 10% technology surcharge on the same base). Loudoun's published fees do not say whether that levy is already included or whether it is charged on plan review, so PermitPrice shows each Loudoun total as a range: the published amount up to 2% more on the building permit and plan review portion (the levy never applies to the zoning permit).
What if my project is over 1,000 sq ft?
For projects over 1,000 sq ft, Loudoun switches from its flat fee to a 1% of construction value formula, plus a $335 plan review fee, plus a separate county zoning permit (cost not published in the fee schedule). For a $100,000 addition, Loudoun's cost would be $1,000 permit + $335 plan review = $1,335.00, or $1,361.70 if the 2% state levy is added, plus the unlisted zoning fee. Fairfax prices a room addition by floor area, not value, under Appendix Q FY2027: a 1,200 sq ft wood-frame addition is $180 permit + $3.60 levy + $18 technology surcharge = $201.60 regardless of the $100,000 declared value - so for large additions Fairfax is the cheaper county.
How do I get an official fee quote?
For Fairfax County: contact Land Development Services at 703-222-0801 or visit the PLUS online portal. For Loudoun County: call Building and Development at 703-777-0220 or use the LandMARC online portal. Only the building department can provide an official fee determination for your specific project.
Tools and Full Data Pages
Go deeper on either county or use the calculator for your project.
Official Sources
-
Fairfax County Land Development Services - Fee Schedule
fairfaxcounty.gov/landdevelopment - Appendix Q PDF
Basis for Fairfax permit fee formula (3% of cost), 10% technology surcharge, minimum fee ($141.75) and the filing-fee deposit credited at issuance (County Code 61-1-3(d)11). Appendix Q FY2027, effective July 1, 2026, verified September 18, 2026. -
Loudoun County - Residential Additions and Alterations Fee Schedule
loudoun.gov/5387/Residential-Additions-and-Alterations
Basis for the Loudoun $395 bundle ($100 building permit + $130 plan review + $165 county zoning permit), 1% large-project formula, and $335 plan review. Fee schedule effective July 1, 2022, re-verified as the current published version November 4, 2026. Verify current schedule directly with Loudoun. -
Code of Virginia §36-137(7) and USBC Section 107.2 - State Levy (2%)
law.lis.virginia.gov/vacode/title36/chapter6/section36-137/
Va. Code 36-137(7) authorizes the levy; USBC Section 107.2 (13VAC5-63-70) requires it at 2% of fees charged for building-code permits, collected by the local building department. It does not apply to county zoning permits.