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Fairfax vs DC Water Heater Permit Fees (2026)

Project-type-specific comparison of water heater permit fees using official fee data from both DMV jurisdictions. For a standalone water heater replacement: Fairfax County charges $346.80 all-in (verified Appendix Q FY2025). Washington DC charges $28.60 (verified DOB schedule, captured April 25, 2026). Fairfax sets a flat $340 floor for any plumbing job of 1 to 5 fixtures, while DC itemizes a single fixture at a low per-fixture rate, so DC is dramatically cheaper for a water heater and stays cheaper at every realistic fixture count. This page covers water heaters only; for all project types see the general DC vs Fairfax permit fee comparison.

Key Takeaways
  • The headline number: a standalone water heater permit is $346.80 all-in in Fairfax County and $28.60 in Washington DC - DC saves $318.20 on the same swap.
  • Fairfax uses a fixture-count plumbing trade permit with a $340 floor (the 1-5 fixture tier), so 1 through 5 fixtures all cost $346.80 all-in. DC itemizes per fixture: $26 first ($28.60 all-in), $20 each additional.
  • There is no crossover in the residential range. Even at 15 fixtures, DC is $336.60 all-in while Fairfax is $475.32 (the 6-15 tier) - DC stays cheaper at every fixture count a home reaches.
  • Fairfax adds Virginia's 2% state levy to the plumbing permit; DC has no state levy but applies a universal 10% DOB Enhanced Fee to its base line items.
  • A DC like-for-like swap can often be filed through DOB's Instant Permit at $28.60. A DC gas conversion or new gas burner is a separate $50.60 line item.
  • Both all-in figures are permit costs only. They do not include the water heater unit, expansion tank, venting, plumber labor, or any gas or electrical work.
Evidence Quality

What Is Verified in This Comparison

Both jurisdictions' water heater data on this page are verified from official sources. No fee amounts are estimated. The Fairfax schedule reflects FY2025 Appendix Q (effective July 1, 2024). The DC schedule is a live page on dob.dc.gov captured April 25, 2026, which states its rates without a stamped effective date.

Data Point Fairfax County Washington DC
Fee schedule source Verified
Appendix Q, LDS Fee Schedule, FY2025 (effective July 1, 2024) 		Verified
DOB Building Permit Fee Schedule (live page, captured April 25, 2026)
Water heater fee method Verified
Plumbing permit by fixture count: $340 for 1-5 fixtures 		Verified
Per fixture: $26 first ($20 each additional)
Add-on fee Verified: 2% levy
Virginia USBC state levy on the permit (Code of Virginia 36-139) 		Verified: 10% Enhanced
Universal DOB Enhanced Fee on base line items
Plan review fee N/A
No plan-review fee on the plumbing trade permit 		N/A
No plan-review fee on a single-fixture plumbing permit
Instant / express option N/A
No instant-permit equivalent in Appendix Q 		Verified: $28.60
Instant Permit per fixture for a like-for-like swap
Standalone water heater all-in Verified: $346.80 Verified: $28.60

Note on schedule currency: The Fairfax Appendix Q data is FY2025 (effective July 1, 2024); an FY2026 schedule may follow around July 2026 - verify with LDS at (703) 222-0801. The DC DOB schedule is a live page without a stamped effective date; PermitPrice captured it April 25, 2026 and re-verifies quarterly - confirm with DOB at (202) 671-3500.

Water Heater Fee Structure Comparison

Head-to-head comparison of how each jurisdiction prices a residential water heater permit. Fairfax sets a flat plumbing-permit floor by fixture count; DC itemizes each fixture at a low per-unit rate.

Fee Component Fairfax County Washington DC
Fee calculation method Plumbing permit by fixture count ($340 for 1-5) Per fixture: $26 first + $20 each additional
Single water heater (1 fixture) $340 permit (flat across 1-5 fixtures) $26 first fixture
Add-on fee 2% Virginia state levy on the permit 10% DOB Enhanced Fee on the base line
Plan review fee None on the plumbing trade permit None on a single-fixture permit
Instant / express option None in Appendix Q Instant Permit per fixture $28.60
Gas conversion / burner Filed as added plumbing scope (confirm with LDS) Separate $50.60 line item
Standalone water heater - all-in total $346.80 Verified $28.60 Verified

Scope note: Both totals are permit costs only. Fairfax's $340 is a flat floor that covers any plumbing job of 1 to 5 fixtures, so a single water heater pays the same as a five-fixture job. DC charges per fixture, so its cost rises with fixture count but starts far lower. Neither figure includes the water heater unit, venting, plumber labor, or any gas or electrical work.

Worked Examples

Three Water Heater Jobs, Two Jurisdictions: Line-by-Line

Each example uses the same job on both sides. Fairfax's flat $340 plumbing floor covers 1 to 5 fixtures, so its cost only changes when the job crosses into the 6-15 tier. DC charges per fixture but starts far lower, so DC is cheaper in all three examples.

Example 1: Standalone water heater replacement (1 fixture)

Fairfax County Verified
Plumbing permit (1-5 fixture tier)
$340.00
2% Virginia state levy
$340 × 2% = $6.80
All-in total
$340 + $6.80 = $346.80
Washington DC Verified
First plumbing fixture (base)
$26.00
10% DOB Enhanced Fee
$26 × 10% = $2.60
All-in total
$26 + $2.60 = $28.60

Result: DC is cheaper by $318.20 on a standalone water heater. A DC like-for-like swap can often use the Instant Permit at the same $28.60.

Example 2: Water heater plus an added utility sink (2 fixtures)

Fairfax County Verified
Plumbing permit (still 1-5 fixture tier)
2 fixtures stays in the 1-5 tier = $340.00
2% Virginia state levy
$340 × 2% = $6.80
All-in total
$346.80
Washington DC Verified
First + one additional fixture
$26 + $20 = $46.00
10% DOB Enhanced Fee
$46 × 10% = $4.60
All-in total
$46 + $4.60 = $50.60

Result: DC is cheaper by $296.20. Fairfax does not change (1-5 tier); DC rises by one fixture but is still far lower.

Example 3: Water heater inside a 6-fixture bathroom remodel

Fairfax County Verified
Plumbing permit (6-15 fixture tier)
6 fixtures crosses into the 6-15 tier = $466.00
2% Virginia state levy
$466 × 2% = $9.32
All-in total
$466 + $9.32 = $475.32
Washington DC Verified
First + five additional fixtures
$26 + (5 × $20) = $126.00
10% DOB Enhanced Fee
$126 × 10% = $12.60
All-in total
$126 + $12.60 = $138.60

Result: DC is cheaper by $336.72 even when the water heater rides inside a six-fixture remodel. The arithmetic for the multi-fixture rows is derived from each jurisdiction's verified per-fixture / per-tier rates.

Does the Gap Ever Close? Fixture-Count Scaling

With a value-scaled fee you would look for a crossover where the cheaper jurisdiction flips. Here there is none in the residential range. Fairfax's flat $340 plumbing floor is higher than DC's per-fixture pricing at every fixture count a home would ever reach, so DC stays cheaper throughout. The table below tracks both at increasing fixture counts (all rows are arithmetic from the verified rates).

Plumbing Fixtures (incl. water heater) Fairfax All-In DC All-In DC Saves
1 (standalone water heater)$346.80$28.60$318.20
2$346.80$50.60$296.20
5$346.80$116.60$230.20
6 (crosses Fairfax tier)$475.32$138.60$336.72
10$475.32$226.60$248.72
15$475.32$336.60$138.72

Even at 15 fixtures - the top of Fairfax's 6-15 tier - DC ($336.60) remains below Fairfax ($475.32). A residential water heater job never approaches the fixture count that would close the gap, so for any homeowner question the practical answer is that DC is cheaper. DC's per-fixture totals are arithmetic from $26 first + $20 each additional, plus the 10% Enhanced Fee.

Why Fairfax and DC Price Water Heaters Differently

The gap comes from two different philosophies of pricing a trade permit, not from one jurisdiction being "expensive" across the board.

Fairfax bundles small plumbing jobs into a single floor. Appendix Q sets the residential plumbing trade permit at $340 for any job of 1 to 5 fixtures. That floor reflects the fixed cost of intake, plan handling, and an inspection regardless of how small the job is. A single water heater pays the same $340 as a five-fixture job, which makes Fairfax's per-job permit relatively high for a one-appliance swap but flat as the job grows within the tier. Virginia's 2% state levy is added on top.

DC itemizes each fixture. The DOB schedule prices plumbing per fixture and appliance - $26 for the first, $20 for each additional - so a single water heater is a small line item ($28.60 with the 10% Enhanced Fee). DC's Instant Permit program lets a like-for-like swap clear at the same $28.60 without a full review. DC has no state levy, but every line carries the universal 10% DOB Enhanced Fee.

The practical takeaway: for a one-appliance job like a water heater, DC's itemized model is far cheaper than Fairfax's flat plumbing floor. The gap narrows only as the fixture count climbs, and even at the top of Fairfax's 6-15 tier DC remains cheaper. For the full single-jurisdiction detail, see the Fairfax water heater guide and the DC water heater guide.

Frequently Asked Questions

Washington DC is much cheaper. A standalone water heater permit is $28.60 in DC versus $346.80 in Fairfax County - a $318.20 difference. DC itemizes a single fixture at a low rate, while Fairfax sets a $340 flat plumbing floor for any job of 1 to 5 fixtures.
Not in the residential range. Fairfax's $340 plumbing floor is higher than DC's per-fixture pricing at every fixture count a home reaches. Even at 15 fixtures - the top of Fairfax's 6-15 tier - DC is $336.60 versus Fairfax's $475.32. A water heater job never approaches the count that would close the gap.
Fairfax's Appendix Q sets the residential plumbing trade permit at a flat $340 for any job of 1 to 5 fixtures. The floor reflects the fixed cost of intake and inspection regardless of job size, so a one-fixture water heater pays the same as a five-fixture job. Virginia's 2% state levy brings it to $346.80.
Often, yes. DOB's Instant Permit prices a plumbing fixture at $28.60, matching the first-fixture rate, and a like-for-like water heater swap is the kind of straightforward scope it is designed for. A gas conversion or added scope may require a standard permit - confirm with DOB.
No. Both the $346.80 and the $28.60 are permit costs only. Neither includes the water heater unit, expansion tank, venting or fittings, the licensed plumber's labor, or any gas-line or electrical work. Those are separate and are usually the larger part of the budget in both jurisdictions.
Fairfax adds Virginia's 2% state levy to the plumbing permit ($6.80 on a $340 permit). DC has no state levy but applies a universal 10% DOB Enhanced Fee to its base line items ($2.60 on a $26 fixture). The add-ons are small relative to the difference in the base permit itself.

Water Heater Guides and Tools

Go deeper on either jurisdiction, run your own numbers, or compare related trade permits.

Official Sources

Official .gov Sources - Verified 2026
Always verify current plumbing permit fees directly with each jurisdiction before budgeting or filing. Fairfax County Appendix Q is FY2025 (effective July 1, 2024); call Land Development Services at (703) 222-0801 or use the PLUS portal. The DC DOB schedule is a live page captured April 25, 2026; call the DC Department of Buildings at (202) 671-3500 or use the DOB permitting portal to confirm the per-fixture rate, Instant Permit eligibility, and any inspection requirements before submitting an application.
Disclaimer: All fee information on PermitPrice is for informational purposes only and is not an official permit quotation. Actual permit fees are determined by Fairfax County Land Development Services and the DC Department of Buildings at the time of application. Fairfax bills the plumbing permit by fixture count plus Virginia's 2% state levy; DC bills per fixture plus the 10% DOB Enhanced Fee. Multi-fixture totals are arithmetic from the verified rates. Permit fees exclude the water heater unit, venting, plumber labor, and any gas or electrical work. Verify directly with each jurisdiction before filing.

Written by: Munib Ur Rehman

Data verified against official fee schedule documents.