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Loudoun County Addition Permit Cost (2026)

Residential addition permit fees in Loudoun County, Virginia, pulled from the Loudoun County Building and Development Residential Fee Schedule (effective July 1, 2022 - the most recent published version on Loudoun's Building and Development site as of April 2026). Loudoun bundles the building permit, the plan review, and the county zoning permit into a single $395 flat fee for residential additions under 1,000 sq ft, and Loudoun's published schedule explicitly lists "addition" under this flat-rate path alongside alterations, decks, and sheds. The 2% Virginia USBC state levy applied to $395 adds $7.90, bringing the all-in addition permit cost to $402.90 for any addition under 1,000 sq ft, regardless of declared construction value, scope, or whether the addition is a bump-out, sunroom, family-room expansion, or kitchen addition. A 200 sq ft mudroom and an 800 sq ft family room cost the same $402.90 under the published schedule. Additions over 1,000 sq ft fall outside the bundled path and use a 1%-of-construction-value formula plus a separate $335 plan review fee, plus the 2% Virginia state levy on the combined building permit subtotal. Source-age caveat applies - the July 2022 schedule is over three years old as of 2026.

Bundled Building Permit (under 1,000 sq ft)
$395 flat
2% Virginia State Levy (on $395)
$7.90
All-In Under 1,000 sq ft
$402.90 (size-independent)
Over 1,000 sq ft Path
1% of value + $335 PR + 2% levy
Last Verified
April 5, 2026
Fee Status
July 2022 schedule
What This Guide Covers - and What It Does Not

This guide covers: Loudoun County, Virginia residential addition permit fees as published in the Loudoun County Building and Development Residential Fee Schedule (effective July 1, 2022). Coverage includes the bundled $395 flat fee that combines the building permit, plan review, and county zoning permit for residential additions under 1,000 sq ft (the path Loudoun's published schedule explicitly assigns to "addition"); the 2% Virginia USBC state levy applied to the $395 bundled subtotal yielding $402.90 all-in; and a worked-example walkthrough of the over-1,000 sq ft pricing path (1% of declared construction value + $335 separate plan review + 2% levy) for larger additions that fall outside the bundled flat path.

This guide does NOT cover: Trade permit fees (electrical, plumbing, mechanical) for additions with utility scope - Loudoun does NOT publish itemized residential trade permit fees in PermitPrice's verified data set, and trade permits are filed separately on top of the building permit, with each trade permit also carrying the 2% Virginia state levy; commercial additions or commercial-use conversions of residential space; new accessory dwelling units (ADUs - separate permit path under Loudoun's residential schedule, not covered by the addition line); detached garages or stand-alone outbuildings (use the shed permit guide or the detached garage path); zoning approvals required before permit submission (rear-yard setback, side-yard setback, lot coverage caps, conservation district overlays, BMP stormwater requirements, well/septic upgrades on rural parcels); HOA architectural review (not a county process - check your covenants); the cost of materials, labor, or the addition construction itself; downstream property tax reassessment that follows a permitted addition.

Source-age caveat (read before budgeting): The Loudoun residential fee schedule referenced here is effective July 1, 2022, and is the most recent published version on Loudoun's Building and Development site as of April 2026. Loudoun may have updated rates internally without a new published PDF, or may publish a revised schedule between PermitPrice's verification cycles. Before relying on the $402.90 figure for a load-bearing budget decision on an under-1,000 sq ft addition, or on the 1% + $335 formula for a larger addition, confirm the current bundled rate and the over-1,000 sq ft pricing with Loudoun Building and Development at (703) 777-0220 or through the BD Apply Online portal. PermitPrice will refresh the source.json on the next verification cycle (due July 15, 2026).

Note on the 1,000 sq ft threshold: Loudoun's published schedule splits residential additions and alterations into two pricing paths at the 1,000 sq ft boundary. Under 1,000 sq ft: bundled $395 flat regardless of declared value. Over 1,000 sq ft: 1%-of-construction-value formula plus a separate $335 plan review fee (the bundled-flat path no longer applies). The threshold is square footage of the addition only, not square footage of the resulting full home. A 200 sq ft mudroom is well within the bundled path; a 1,200 sq ft second-story addition is on the over-1,000 sq ft path. The pricing difference can be large: a $150,000 declared 1,200 sq ft second-story addition runs approximately $1,871.70 all-in vs $402.90 if it qualified for the bundled path. Verify with Loudoun Building and Development which path applies before filing a budget.

Key Takeaways
  • Loudoun's residential addition permit splits at the 1,000 sq ft boundary into two pricing paths. Under 1,000 sq ft: bundled flat $395 (building permit + plan review + zoning permit) plus 2% Virginia state levy = $402.90 all-in regardless of declared construction value. Over 1,000 sq ft: 1% of declared value building permit + $335 separate plan review + 2% levy on the combined building permit subtotal.
  • For typical residential additions under 1,000 sq ft (mudrooms, sunrooms, family-room expansions, master-suite bump-outs, kitchen additions), the all-in fee is a flat $402.90. A 200 sq ft mudroom and an 800 sq ft family room both cost the same $402.90 under the published schedule - the bundled-flat structure produces predictable pricing but does not reward smaller additions or penalize larger ones below the 1,000 sq ft threshold.
  • For additions over 1,000 sq ft (large second-story additions, primary-suite over garage, multi-room family-room + bedroom + bath addition), the 1% + $335 path applies. A $150,000 declared 1,200 sq ft second-story addition runs approximately $1,500 building permit + $335 plan review = $1,835 subtotal, plus 2% levy = $36.70, for $1,871.70 all-in. The over-1,000 path scales with declared construction value and adds the separate plan review.
  • The 2% Virginia state levy is required by Code of Virginia Section 36-139 and USBC Section 107.2. Loudoun applies it to the building permit fee subtotal (the $395 flat under the bundled path, or the 1% + $335 combined subtotal under the over-1,000 path). The levy is a state-collected pass-through to the Virginia Department of Housing and Community Development - same statutory authority every Virginia jurisdiction operates under.
  • Trade permits (electrical, plumbing, mechanical) for additions with new circuits, fixtures, or HVAC equipment are filed SEPARATELY in Loudoun on top of the building permit. Loudoun does NOT publish itemized residential trade permit fees in PermitPrice's verified data. A typical mid-range family-room addition might include one electrical permit (range $135-$400 in most DMV jurisdictions), one plumbing permit if a wet bar or half-bath is added (similar range), and one mechanical permit if HVAC ductwork is extended. Each trade permit also carries the 2% Virginia state levy. Verify trade permit costs directly with Loudoun Building and Development at (703) 777-0220.
  • The "declared construction value" field on the Loudoun addition permit application is collected but does not change the bundled fee under 1,000 sq ft. Under the over-1,000 sq ft path, declared value directly drives the 1% building permit fee math, so honest declaration matters significantly. Under-declaring construction value on a large addition can save permit money short-term but can trigger administrative correction requests, re-inspection delays, or downstream property assessment complications. Inspectors typically verify declared value against the as-built scope.
  • Loudoun's bundled flat fee under 1,000 sq ft is jurisdiction-unique in the DMV - no other verified Virginia county or city combines building permit, plan review, AND zoning permit into a single bundled fee at this scale. The structure produces predictable pricing for typical residential additions but lands more expensive than value-based jurisdictions like Henrico County (capped at $693.60 all-in) or Richmond City (uncapped value formula) for low-value additions, and cheaper than Fairfax County (3% formula uncapped) for mid-range additions.
  • For a $50,000 declared family-room addition under 1,000 sq ft, Loudoun's $402.90 sits roughly in the middle of the DMV. Virginia Beach charges approximately $121.70 for a 500 sq ft heated addition with counter plan review. Henrico County charges $377.40 ($100 + 45 x $6 + 2% levy). Chesterfield County charges $456.98 (flat $399 + $50 EE + 2% levy). Fairfax County charges approximately $2,295 ($1,500 + $750 + $45). Richmond City charges approximately $361.45 (uncapped value formula). See the Virginia addition permit guide for the full cross-jurisdiction comparison.
Calculate Your Addition Permit All Loudoun Permit Fees

Loudoun Addition Permit Fee Components

Loudoun's residential addition permit fee splits into two distinct component structures depending on whether the addition is under or over 1,000 sq ft. Under 1,000 sq ft, the bundled $395 flat building permit + plan review + zoning permit is a single line, and the 2% Virginia state levy applies on top - the same $402.90 all-in regardless of declared construction value. Over 1,000 sq ft, the building permit becomes 1% of declared construction value, a separate $335 plan review fee is added, and the 2% levy applies to the combined building permit subtotal. The breakdown below shows component math at both pricing paths.

Component 200 sq ft mudroom ($25k) 500 sq ft sunroom ($50k) 800 sq ft family room ($80k) 1,200 sq ft second-story ($150k)
Bundled building permit (under 1,000 sq ft path) $395.00 $395.00 $395.00 N/A (over-threshold)
1% building permit (over 1,000 sq ft path) N/A N/A N/A $1,500.00
Separate plan review (over 1,000 sq ft only) N/A (bundled) N/A (bundled) N/A (bundled) $335.00
Building permit subtotal $395.00 $395.00 $395.00 $1,835.00
2% Virginia state levy $7.90 $7.90 $7.90 $36.70
All-in addition permit total $402.90 $402.90 $402.90 $1,871.70

Source: Loudoun County Building and Development Residential Fee Schedule (effective July 1, 2022 - most recent published version). The bundled $395 flat fee combines the building permit, plan review, and county zoning permit for residential additions and alterations under 1,000 sq ft; the published schedule lists "addition" under this flat-rate path. The 1%-of-construction-value formula plus the $335 separate plan review applies to additions over 1,000 sq ft. The 2% state levy is required by Code of Virginia Section 36-139 and USBC Section 107.2; Loudoun applies it to the full bundled amount under the under-1,000 path and to the combined building permit subtotal under the over-1,000 path. Trade permit fees (electrical, plumbing, mechanical) are excluded - Loudoun does not publish itemized residential trade permit fees in PermitPrice's verified data.

Worked Examples - Real Addition Projects in Loudoun County

The first three worked examples below all return $402.90 because the bundled flat fee is size-independent and value-independent under the 1,000 sq ft ceiling. The fourth example crosses the 1,000 sq ft threshold and uses the 1% + $335 path. The declared construction value should reflect the honest contractor invoice or materials-plus-labor figure - under-declaring saves nothing under the bundled path and risks administrative complications under the over-1,000 sq ft path where declared value directly drives the math.

Example 1: 200 sq ft mudroom bump-out, $25,000 declared

A homeowner extends the kitchen rear wall by 200 sq ft to add a mudroom with cubbies, a coat closet, and a tile floor. New exterior wall, new roof framing, one window, one exterior door, and minor electrical (two outlets, two overhead lights wired to a switch on existing circuits). Total addition area: 200 sq ft. Contractor invoice: $25,000 (framing, finish work, basic finishes).

  • Addition area: 200 sq ft (well under the 1,000 sq ft bundled threshold)
  • Declared value: $25,000 (recorded but does not change the fee)
  • Bundled building permit + plan review + zoning permit: $395.00
  • 2% Virginia state levy on $395: $7.90
  • Building permit total: $402.90

Note: the electrical work for the mudroom (two outlets, two lights on existing circuits) likely requires a separate residential electrical permit on top of the $402.90 building permit. Loudoun does not publish itemized trade permit tiers in PermitPrice's verified data - verify trade permit cost directly with Loudoun Building and Development at (703) 777-0220 before total project budgeting.

Example 2: 500 sq ft sunroom addition, $50,000 declared

A homeowner adds a 500 sq ft glass-roof sunroom on a slab foundation off the rear of the home. New exterior walls (three sides glass curtain wall), engineered roof structure, four overhead lights with switches, three outlets, and zoned mini-split HVAC. Total addition area: 500 sq ft. Contractor invoice: $50,000 (premium glazing, finish flooring, HVAC, electrical rough-in).

  • Addition area: 500 sq ft (still under the 1,000 sq ft bundled threshold)
  • Declared value: $50,000 (recorded but does not change the fee)
  • Bundled building permit + plan review + zoning permit: $395.00
  • 2% Virginia state levy on $395: $7.90
  • Building permit total: $402.90

Note: this $50,000 sunroom would cost $377.40 in Henrico County ($100 + 45 x $6 = $370 + 2% levy = $377.40), $361.45 in Richmond City ($63 + 48 x $6.07 = $354.36 + 2% levy = $361.45), and approximately $2,295 in Fairfax County ($1,500 + $750 PR + $45 levy). Loudoun's $402.90 lands in the middle of the DMV. Trade permits for the electrical and HVAC scope are not included and would add separately.

Example 3: 800 sq ft family room + bedroom addition, $80,000 declared

A homeowner adds an 800 sq ft single-story addition combining a family room and a bedroom off the rear of the home. New foundation, framed exterior walls, full roof structure, six windows, two exterior doors, full electrical (eight circuits, ceiling fans, overhead lighting, eleven outlets), and zoned forced-air HVAC extension. Total addition area: 800 sq ft. Contractor invoice: $80,000 (full-build addition, finished interior, HVAC, electrical, finish carpentry).

  • Addition area: 800 sq ft (still under the 1,000 sq ft bundled threshold)
  • Declared value: $80,000 (recorded but does not change the fee)
  • Bundled building permit + plan review + zoning permit: $395.00
  • 2% Virginia state levy on $395: $7.90
  • Building permit total: $402.90

Note: this is where Loudoun's bundled approach becomes structurally favorable. The same $80,000 declared 800 sq ft addition would cost approximately $3,672 all-in in Fairfax County ($2,400 + $1,200 PR + $72 levy at the 3% formula). Loudoun's $402.90 is roughly 11% of the Fairfax price for the same project. The structural advantage shrinks for additions just over the 1,000 sq ft threshold (since Loudoun's over-1,000 path uses the 1% formula plus $335 PR), but for any under-1,000 sq ft addition Loudoun is dramatically cheaper than the Fairfax 3% formula. Trade permits not included.

Example 4: 1,200 sq ft second-story addition, $150,000 declared (over 1,000 sq ft path)

A homeowner builds a 1,200 sq ft second-story addition over the existing ranch home - new master suite with sitting room, two secondary bedrooms, a full bath, and a half bath. Structural steel reinforcement of the existing first-floor framing, new staircase, full electrical (twelve circuits), full HVAC second zone with new air handler, full plumbing (two full baths + half bath rough-in). Total addition area: 1,200 sq ft. Contractor invoice: $150,000 (structural retrofit, framing, exterior shell, full mechanical, full plumbing, full electrical, interior framing, drywall, paint, finished flooring).

  • Addition area: 1,200 sq ft (crosses the 1,000 sq ft threshold)
  • Declared value: $150,000 (load-bearing under the 1% formula)
  • 1% building permit: $150,000 x 0.01 = $1,500.00
  • Separate plan review fee: $335.00
  • Building permit subtotal: $1,835.00
  • 2% Virginia state levy on $1,835: $36.70
  • Building permit total: $1,871.70

Note: this is the structural pricing flip when a Loudoun addition crosses the 1,000 sq ft threshold. The same $150,000 second-story addition would cost approximately $6,885 all-in in Fairfax County ($4,500 + $2,250 PR + $135 levy at the 3% formula uncapped), $693.60 in Henrico County (caps at $680 building permit + $13.60 levy - Henrico is structurally cheapest for high-value additions), and approximately $1,599.73 in Richmond City (uncapped $63 + $6.07/$1k formula). Loudoun's over-1,000 path lands competitive with Richmond and well below Fairfax at this scale, but Henrico's $693.60 cap is the structural winner for any high-value addition. Trade permits, plumbing fixture permits, and the HVAC second-zone permit are not included and would add separately on top of the $1,871.70.

Calculate Your Loudoun Addition Permit

The PermitPrice fee calculator supports Loudoun County's bundled flat-fee approach directly for additions under 1,000 sq ft. Pick "Loudoun County, VA" and "Addition" in the calculator dropdowns; the calculator returns $402.90 for any addition under 1,000 sq ft, because the bundled fee does not scale with declared construction value or footprint within the under-1,000 path. The over-1,000 sq ft path (1% of value + $335 PR + 2% levy) is documented in this guide with worked-example math but is not currently wired into the calculator UI as a primary path - confirm pricing with Loudoun Building and Development for any addition that crosses the 1,000 sq ft threshold.

Calculator coverage for Loudoun additions: the bundled $395 flat building permit + plan review + zoning permit, plus the 2% Virginia state levy, is calculator-supported for under-1,000 sq ft additions. The over-1,000 sq ft path (1% + $335 PR) is documented here but not currently wired as a primary calculator path - confirm with Loudoun Building and Development at (703) 777-0220 for additions over 1,000 sq ft.

Open the Permit Fee Calculator

Trade Permits for Additions in Loudoun

Residential additions with electrical, plumbing, or mechanical scope require separate trade permits beyond the building permit in every Virginia jurisdiction. Loudoun is not an exception - most additions include new electrical circuits, light fixtures, and HVAC ductwork, and additions with kitchens, bathrooms, or wet bars also require plumbing permits. Each trade permit is filed separately and carries the 2% Virginia state levy on top of its trade fee.

Itemized residential trade permit fees for Loudoun are NOT in PermitPrice's verified data. Loudoun's residential fee schedule (effective July 1, 2022) bundles the building permit, plan review, and zoning permit for sub-1,000 sq ft additions into the $395 flat fee, but does NOT include itemized electrical, plumbing, or mechanical trade permit tiers for residential work in the source.json record PermitPrice maintains. Verify trade permit costs directly with Loudoun Building and Development at (703) 777-0220 or through the BD Apply Online portal before budgeting any addition with utility scope.

For rough budgeting only (not verified Loudoun-specific trade-permit data), DMV-area residential trade permit fees typically run $135-$400 per trade depending on amperage, fixture count, or zone count. A typical $50,000 sunroom addition with electrical + HVAC trade permits could add $300-$700 on top of the $402.90 building permit. A typical $80,000 family-room addition with electrical + HVAC + minor plumbing could add $400-$900. Treat any trade permit cost as an estimate until confirmed directly with Loudoun. PermitPrice will refresh the Loudoun source.json with itemized trade permit data on the next verification cycle if the published schedule expands its residential trade detail.

Loudoun Addition Permit Cost vs Virginia Neighbors and DC

Loudoun's bundled $395 flat fee under 1,000 sq ft is structurally unique in the DMV. The table below compares the all-in cost of a typical $50,000-$80,000 declared family-room addition under 1,000 sq ft across DMV jurisdictions. Loudoun's predictability favors smaller and mid-range additions but is dramatically cheaper than Fairfax's 3% formula at high declared values.

Jurisdiction Addition Pricing Method $50k-$80k Addition Under 1,000 sq ft
Loudoun County Bundled $395 flat + 2% levy $402.90
Virginia Beach $50 + $7/100 sq ft heated + $25 counter PR + $10 tech + 2% levy $121.70-$203.84
Richmond City $63 + $6.07/$1,000 over $2,000 + 2% levy $361.45-$547.19
Henrico County $100 + $6/$1,000 over $5,000 (cap $680) + 2% levy $377.40-$561.00
Chesterfield County $399 flat + $50 EE + 2% levy $456.98
Norfolk City $0.15/sq ft + tiered PR + $15 + 2% levy $126.50-$625.50
Fairfax County 3% of value + 50% PR + 2% levy $2,295.00-$3,672.00
Washington, DC 4-tier alteration formula + 10% Enhanced + 0.13% GBF $1,233.10-$1,937.36

"$50k-$80k addition under 1,000 sq ft" assumes a typical mid-range residential addition under 1,000 sq ft at $50,000-$80,000 declared construction value. Building permit only - trade permits excluded across all jurisdictions. Virginia Beach's range reflects $121.70 for 500 sq ft heated addition with counter PR up to $203.84 for 800 sq ft heated. Richmond's range reflects $50k-$80k declared at the $63 + $6.07/$1k formula. Henrico's range reflects $50k-$80k declared at the $100 + $6/$1k formula. Norfolk's range reflects 500 sq ft heated ($126.50) up to 800 sq ft heated ($188.60 at the formula) - the $625.50 figure reflects a 3,500 sq ft heated addition for a tier comparison. Fairfax's $2,295-$3,672 reflects $50k-$80k declared at 3% + 50% PR + 2% levy. DC's range reflects the Tier 3 alteration formula ($30 + 2% of value over $1k) plus 10% Enhanced plus 0.13% GBF + 10% Enhanced.

Side-by-Side Math

For a full breakdown of how Loudoun and other Virginia jurisdictions price additions, see the statewide guide.

Frequently Asked Questions

Loudoun bundles the building permit, plan review, and county zoning permit into a single $395 flat fee for residential additions and alterations under 1,000 sq ft. The bundled flat-fee structure does not scale with footprint or declared construction value below the 1,000 sq ft threshold - the same $395 applies whether you are building a 200 sq ft mudroom or an 800 sq ft family room. Adding the 2% Virginia state levy on $395 ($7.90) brings the all-in total to $402.90 for every sub-1,000 sq ft residential addition. This structure is structurally different from value-based jurisdictions like Fairfax County (3% of declared value, scaling with project cost) or square-foot-based jurisdictions like Virginia Beach ($7 per 100 sq ft heated, scaling with footprint). Loudoun's predictability is the main benefit; the trade-off is that small additions in Loudoun cost more than equivalent small additions in lower-fee jurisdictions.
Additions over 1,000 sq ft fall outside Loudoun's bundled flat-fee path. Loudoun's residential schedule applies a 1%-of-construction-value formula plus a separate $335 plan review fee for residential additions and alterations over 1,000 sq ft, with the 2% Virginia state levy on the combined building permit subtotal. A 1,200 sq ft second-story addition at $150,000 declared value runs $1,500 building permit + $335 plan review = $1,835 subtotal, plus 2% levy = $36.70, for $1,871.70 all-in. The pricing difference between the under-1,000 path ($402.90 flat) and the over-1,000 path can be large at higher declared values - a $250,000 declared 1,400 sq ft addition would run $2,335 building permit subtotal + $46.70 levy = $2,381.70 all-in. The 1,000 sq ft threshold is the single most important pricing line for Loudoun additions.
Not for fee math - the declared value field is recorded on the application but does NOT change the bundled $395 fee under 1,000 sq ft. Under the bundled flat-fee path, increasing declared value from $25,000 to $50,000 does not change the fee. Inspectors still record the declared value for permit history, county assessment records, and downstream property tax reassessment when the addition is added to the parcel record. The honest contractor invoice or materials-plus-labor figure should still be filed - under-declaring saves no permit money under the bundled structure (the fee is flat regardless) and may trigger administrative complications if a future inspector or assessor disputes the declared value. Under the over-1,000 sq ft path, declared value directly drives the 1% building permit fee math, so honest declaration matters significantly for budget purposes.
Trade permits are filed SEPARATELY in Loudoun on top of the building permit. The bundled $402.90 building permit fee under the under-1,000 path covers the building permit, plan review, and zoning permit components only - it does NOT cover the electrical, plumbing, or mechanical trade permits required for new circuits, fixtures, or HVAC equipment. Loudoun does NOT publish itemized residential trade permit tiers in PermitPrice's verified data set. Expect a separate residential electrical permit (range $135-$400 in most DMV jurisdictions depending on amperage tier), a separate plumbing permit if the addition includes a bathroom, kitchen, or wet bar (similar range), and a separate mechanical permit if HVAC ductwork is extended. Each trade permit also carries the 2% Virginia state levy. A typical $80,000 family-room addition with electrical + HVAC + minor plumbing could add $400-$900 in trade permits on top of the $402.90 building permit. Verify trade permit costs directly with Loudoun Building and Development at (703) 777-0220.
For any sub-1,000 sq ft residential addition, Loudoun is dramatically cheaper than Fairfax. A $50,000 declared 500 sq ft sunroom in Loudoun costs $402.90; the same project in Fairfax County costs approximately $2,295 ($1,500 + $750 PR + $45 levy at the 3% formula). A $80,000 declared 800 sq ft family-room addition in Loudoun costs $402.90; the same project in Fairfax costs approximately $3,672 ($2,400 + $1,200 PR + $72 levy). The Loudoun bundled path saves $1,892-$3,269 vs Fairfax for typical residential additions under 1,000 sq ft. For additions over 1,000 sq ft, the comparison narrows - a $150,000 1,200 sq ft second-story addition is $1,871.70 in Loudoun vs approximately $6,885 in Fairfax, but the Loudoun price climbs with declared value while Fairfax has no addition cap. Above approximately $400,000 declared, the Loudoun over-1,000 path becomes comparable to Fairfax at the same scale.
The July 1, 2022 Loudoun residential fee schedule is the most recent published version on Loudoun's Building and Development site as of April 2026 - it is over three years old. Loudoun has not posted a newer published PDF version, but the county may have updated internal rates without a new public posting, or may have a draft schedule pending publication. PermitPrice's source.json lists the confidence level for the Loudoun addition fee as "medium with caveats" specifically because of the schedule age. Before filing a load-bearing budget decision for a Loudoun addition permit, confirm the current bundled rate and the 1% + $335 over-1,000 sq ft formula with Loudoun Building and Development at (703) 777-0220 or through the BD Apply Online portal. PermitPrice will refresh the Loudoun verification on the next cycle (due July 15, 2026). If the schedule has changed, the bundled flat fee or the 1% rate may differ from the figures in this guide.
Per Loudoun's published schedule, the 1,000 sq ft threshold is the square footage of the addition itself, not the resulting full home post-addition. A 300 sq ft mudroom added to a 2,800 sq ft existing home stays in the bundled under-1,000 path because the addition itself is 300 sq ft. An 1,100 sq ft second-story addition to the same 2,800 sq ft existing home crosses the threshold because the addition itself is over 1,000 sq ft. Verify with Loudoun Building and Development at (703) 777-0220 if your project is borderline or includes both ground-floor and second-floor scope - bundled vs over-1,000 classification can shift the all-in fee by thousands of dollars on large projects.
Per the Loudoun residential fee schedule (effective July 1, 2022), the $395 bundled flat fee for additions under 1,000 sq ft explicitly includes the county zoning permit alongside the building permit and the plan review. This is structurally unique in the DMV - no other verified Virginia jurisdiction in PermitPrice's data set bundles the zoning permit into the building permit fee. In most jurisdictions, zoning approval is either an upstream entitlement process (handled by a separate Planning department) or is folded into a separate land-disturbance or site-development permit. Loudoun's bundling of the zoning permit into the $395 is a real cost savings vs jurisdictions where zoning is a separate filing - though for additions that require a special use permit, variance, or rezoning approval (beyond the standard residential zoning permit), those higher-order entitlement processes are NOT covered by the bundled $395 and are filed and paid separately under the Loudoun Planning and Zoning fee schedule. The $402.90 figure covers only the standard residential building + plan review + zoning permit bundle for a by-right addition under 1,000 sq ft.

Sources

Official .gov Sources - Verified April 2026
  • Loudoun County Building and Development - Residential Fee Schedule Effective July 1, 2022 (FY2023) - Loudoun County Government - Primary source for the bundled $395 flat fee covering building permit, plan review, and county zoning permit for residential additions under 1,000 sq ft, and for the 1%-of-construction-value formula plus the $335 separate plan review fee for additions over 1,000 sq ft. Source schedule is the most recent published Loudoun residential version as of April 5, 2026 verification - source-age caveat applies; this schedule is over three years old as of 2026. Caveat
  • Loudoun BD Apply Online - Permit Portal Accessed April 5, 2026 - Loudoun County Building and Development - Official online portal for submitting building, electrical, plumbing, and mechanical permits in Loudoun; the destination for verifying current bundled-flat vs over-1,000 sq ft pricing classification and for confirming trade permit costs not itemized in PermitPrice's source data
  • Code of Virginia Section 36-139 - USBC State Levy Authority Current - Virginia General Assembly - Authorizing statute for the statewide 2% building permit surcharge applied in Virginia jurisdictions, including the $7.90 levy applied to the Loudoun bundled $395 addition permit fee under the under-1,000 path and the levy on the combined building permit subtotal under the over-1,000 path
Next Step

Calculate your specific Loudoun addition permit cost, see all Loudoun fee categories, or compare against Virginia neighbors.

Always verify current addition permit fees, the under-vs-over 1,000 sq ft pricing classification, and trade permit costs directly with Loudoun County Building and Development before budgeting or filing. The Loudoun residential fee schedule effective July 1, 2022 is the most recent published Loudoun version and is the source of truth for this guide - but it is over three years old as of 2026 and may not reflect current rates. Call Loudoun Building and Development at (703) 777-0220 to confirm the bundled $395 flat fee is still in effect for additions under 1,000 sq ft, to confirm the 1% + $335 plan review formula is still in effect for additions over 1,000 sq ft, and to get itemized trade permit costs if your addition includes electrical, plumbing, or mechanical scope.
Disclaimer: All fee information on PermitPrice is for informational purposes only and is not an official permit quotation. Actual permit fees are determined by Loudoun County Building and Development at the time of application. The bundled $395 flat fee plus $7.90 state levy ($402.90 all-in) for additions under 1,000 sq ft, and the 1% building permit + $335 plan review + 2% state levy formula for additions over 1,000 sq ft, are both sourced from Loudoun's published residential fee schedule effective July 1, 2022 - the most recent published version on Loudoun's Building and Development site as of April 2026, over three years old. Loudoun may have updated rates internally without a new published PDF. Trade permit fees (electrical, plumbing, mechanical) for residential additions in Loudoun are not itemized in PermitPrice's verified data. Special use permits, variances, rezoning, BMP stormwater approvals, well/septic upgrades, and other higher-order entitlement processes are NOT covered by the bundled $395 and are filed and paid separately under Loudoun Planning and Zoning fee schedules. Zoning compliance (setbacks, lot coverage, conservation district overlays) is part of the by-right zoning permit included in the bundled $395 but does not cover special exceptions or variances.

Written by: Munib Ur Rehman

Data verified against official fee schedule documents.