Written by Amanda Casteel · COO Reviewed by Johnny Casteel · CEO · Master Plumber Updated July 2026 VA Plumbing Lic. 2710075081 · Contractor Lic. 2705180998
Quick answers
- NoVA (2021 USBC): gas/oil appliance replacement always needs a permit; identical electric like-for-like usually doesn’t.
- DC: homeowners can’t pull trade permits — Instant Permits ~$29 WH plumbing / $29 gas; unpermitted work risks $2,000/infraction.
- Montgomery & PG: WSSC permits plumbing/gas (Short Form ~$180 as of July 1, 2026); county handles electrical/mechanical.
- Unpermitted prior work is fixable but expensive at sale — we handle retroactive permits, including closing deadlines.
When to use this guide
Use this before a water heater, gas, panel, EV circuit, repipe, or sewer project — or when an inspection finds unpermitted prior work.
The one rule that covers most of Northern Virginia
Gas or oil appliance replacement always requires a permit — even exact like-for-like. Identical electric replacement in the same location usually doesn’t. Anything that changes the system (new EV circuit, panel upgrade, repipe, moving equipment, gas-to-electric) needs a permit everywhere.
Washington, DC
Everything needs a permit; homeowners can’t pull trade permits — only licensed, bonded masters. Instant Permits issue online for common jobs (~$29 water heater plumbing, ~$29 per gas appliance, ~$22 small electrical, ~$65 heavy-up to 200A). Working without one risks $2,000 per infraction. Sewer work in public space needs a separate DDOT permit.
Montgomery & Prince George’s — the two-agency trap
Plumbing and all gas work = WSSC Water permits, not the county. Electrical/mechanical = county (DPS / DPIE). A gas furnace swap can need three permits. WSSC Short Form replacements ~$180 pre-paid (July 1, 2026). Homeowners: limited plumbing after affidavit + exam; gas work never allowed for homeowners. PG after-the-fact: $500 per discipline per first offense.
Fairfax, Arlington, Alexandria, Loudoun, Prince William
Fairfax: gas always permitted; electric like-for-like exempt; A2L refrigerant cert on new heat pump/AC. Arlington: gas swap + vent/chimney inspection; outdoor equipment may need zoning. Alexandria: APEX portal, min fee $95 (July 1, 2025 schedule). Loudoun: some residential gas permits need plan review as of Oct 1, 2025. PWC: clearest homeowner exemptions for identical electric swaps and fixture-only plumbing — still permits gas/oil, new circuits, alterations; formal process to legalize unpermitted work.
Unpermitted prior work — and what we do
Finding unpermitted work at inspection is routine. Current owner inherits it. Retroactive permits exist (PG $500/discipline; DC can fine $2,000 if reported). Practical cost is often opening walls for inspectors. Agents call us for 48-hour close deadlines — doable more often than you’d think, but the most expensive time to fix a $30 permit decision. We pull permits, schedule inspections, bake fees into quotes; on no-water jobs we can restore service same/next day and finish after the permit issues.
Failure modes to avoid
Skipping the permit to “save a week”
Sale discoveries and forfeited rebates (e.g. DCSEU verifies permits) cost far more than the fee.
Hiring a NoVA-only plumber for WSSC gas work
Ask who holds WSSC credentials before you book Montgomery or Prince George’s gas jobs.
Proof & methodology
- · Written by Amanda Casteel (COO), reviewed by Johnny Casteel (CEO · Master Plumber) — Cherry Blossom Plumbing (VA Plumbing Lic. 2710075081).
- · Sources verified July 16, 2026: DC DOB, WSSC, Montgomery DPS FY27, PG DPIE, Fairfax LDS, Arlington, Alexandria, Loudoun, PWC, Virginia DHCD.
Last updated July 2026
Starting prices (NoVA)
These are Cherry Blossom Plumbing’s actual installed ranges for the DC metro area (July 2026) — not national averages or teaser rates. Low end = straightforward access; high end is real too. Every range includes the permit when one is required. Final flat-rate is confirmed after on-site diagnosis.
Virginia daytime diagnostic $75 — waived with repair. DC & Maryland daytime $150. After-hours: $150 VA / $250 DC-MD. Free while-we’re-in-the-neighborhood estimates; free second opinions with a written competitor quote.
- Gas line repairfrom $350
- Gas line installfrom $750
- PRV / main shutoff valve$650 – $1,400
- Daytime diagnostic (VA)$75 — waived with repair
FAQs
Will Cherry Blossom pull the permit?
Yes — including WSSC-plus-county combinations. Fees are included in the quote you approve (exception: tagging onto a GC’s existing building permit).
How long do permits take?
Most Virginia counties: 2–8 days for our trade permits; Alexandria and Falls Church often 3–14. We can restore water/sewer before final inspection when needed.
Can you fix unpermitted work before closing?
Often yes — assess what’s behind the walls and run the retroactive permit path. Call (703) 214-2551 with the deadline.
Next step
Ready for help in Arlington or Northern Virginia? We diagnose first, explain options in flat-rate terms, and never upsell what you do not need.