Plumbing in Loudoun County

What you need to know about permits, published fees and inspections. Plus the plumbing problems Loudoun's water providers and Health Department actually document.

We've included a source and gathering date for every figure. Published targets are still only targets. Where we could not settle something, we say so.

Do you actually need a permit?

You generally need a permit to change the plumbing system. Replacing a fixture without changing the system can be exempt. Virginia's permit rule covers installing or altering water distribution, sanitary drainage, and vent systems. A repipe or a relocated bathroom crosses that line.

You can replace plumbing fixtures and well pumps under the ordinary-repair exemption without altering the supply, distribution, drainage, or vent systems. Replacing a toilet on its existing connections is different from moving its drain. Exempt work must still meet the code. In a special flood hazard area, the building official can require a permit for otherwise exempt work.

You can start emergency construction, alterations, or equipment replacement before applying for a permit. You must apply by the end of the next working day. That deadline does not let you leave emergency work undocumented.

Check what your water-heater job needs. Loudoun's plumbing application lists water heaters, water lines, sewer lines, and sewer/sump pumps. Its gas application also lists water heaters. Those forms list the kinds of work that need permits. They do not explain every replacement exemption.

We could not settle this replacement detail. The state separately exempts certain replacement mechanical appliances that do not burn gas or oil. We found no Loudoun ruling applying that exemption to every like-for-like electric water-heater replacement. Check before treating yours as exempt. Building and Development can tell you which category your work falls into at 703-777-0220, option 1. Describe the fuel, location, and piping changes.

Source: Virginia DHCD, 13VAC5-63-80, Section 108, effective 2024-01-18; Loudoun County Building and Development, Plumbing Permit Application, dated 2017-07-13, Gas Permit Application, dated 2017-07-16, and Building Inspections, undated. Gathered 2026-09-22.

What the permit costs

Loudoun's current fee page still links to the schedule effective July 1, 2022. These are the listed county plumbing charges. They do not estimate what a contractor charges to handle your permit.

The plumbing permit fee includes two inspections. These are separate entries in the schedule. Do not automatically add every row if your job involves interior and exterior work. The county decides which permits and charges apply from your application. New-building fees include the associated trade permit fees under a separate system based on value.

Gas work has a newer rule. Since October 1, 2025, residential gas alterations and additions needing plan review cost $70 base fee plus $65 review fee: $135. The notice waives plans for replacement permits with no increase in BTU input or change in appliance location. You still need a permit. For a higher-input tankless conversion, have the gas work checked against these requirements.

Paying by credit card adds a published 2.65% convenience fee. You can also pay by cash or cheque. Keep the county invoice separate from any contractor charge for preparing applications or attending inspections.

The payment instructions conflict. The general fee page says payment is due at intake, before review. The finished-basement page says you pay after review. We have used the general fee page's intake instruction. The residential processing dashboard backs that up. Follow your actual LandMARC invoice. If the timing is unclear, check at 703-777-0220.

Source: Loudoun County Building and Development, Application Fee Schedule, effective 2022-07-01, pages 9–12; Fee Schedules and Payment Options, undated; Residential Fuel Gas Permit Notice, posted and effective 2025-10-01; Finished Basements and Residential Permits Processing Dashboard, undated. Gathered 2026-09-22.

How long the permit actually takes

The county publishes expected processing times. These do not promise when your plumber can start.

Incomplete paperwork can hold up your application. So can unpaid fees. Intake takes place before review. The trade review target alone does not cover the whole time from applying to approval.

Two things remain unclear. The dashboard gives intake times in business days. It calls review times simply days. We have kept those units as published. The general trade target also differs from the gas-specific notice. For gas work needing plans, we have used the more specific gas notice. Check your schedule through the dashboard's permit-status inquiry or Building and Development.

We could not verify Loudoun's actual median time from application to issuance for residential plumbing permits. Do not treat the targets as measured turnaround times. They leave out the wait for your contractor. They also leave out the time needed to book inspections.

Source: Loudoun County Building and Development, Residential Permits Processing Dashboard, undated; Residential Fuel Gas Permit Notice, posted and effective 2025-10-01. Gathered 2026-09-22.

The inspections

For residential additions and alterations, Loudoun lists plumbing inspections at rough-in and final. The order depends on the permitted work. An exposed equipment replacement needs different inspection arrangements from new pipes behind basement walls.

For a finished basement, plumbing rough-in that will be concealed must pass before the building-framing inspection. Get framing approved before you cover anything up. Keep the approved plans or accepted county basement details on site. The county says the inspection will not proceed without them. Settle the inspection schedule before you book drywall installation.

Book inspections through LandMARC. You can request the following working day or a later date. Weekends and county holidays are excluded. The next-working-day cutoff is midnight. Published inspection hours are 8:30 a.m.–3 p.m., Monday–Friday.

The portal shows your inspection date, time, inspector, and results. You can also cancel there. You can reach inspectors in the office 8–8:30 a.m. and 3–4 p.m. on weekdays at 703-777-0220, option 1. Those are contact hours, not a promised arrival window.

You may face a reinspection charge if the work is not ready when you request an inspection. Keep the result with your job records. Running water alone does not mean your permitted job has passed final inspection.

Source: Loudoun County Building and Development, Residential Additions and Alterations, Finished Basements, and Building Inspections, undated live guidance. Gathered 2026-09-22.

What the inspector is actually going to check

These Virginia residential-code rules apply to household plumbing. We are not claiming they are Loudoun's most common inspection failures:

• Water-heater leak protection: a storage tank needs a pan where a leak would cause damage. Virginia expressly bans plastic pans beneath gas-fired water heaters.
• Replacement gas equipment: the connected vent or chimney must be checked for correct sizing, blockages, deterioration, and whether it works. If the local building department does not inspect it, the installer must certify to the building official that it complies.
• A replacement plastic water service connected to a public system: the pipe must be locatable. The rule calls for insulated copper tracer wire of at least 18 AWG, or an equivalent product. The wire must be suitable for burial. It must run in the same trench, within 12 inches of the pipe. Its end must be accessible as the code specifies.
• Quick-closing valves: you need a water-hammer arrestor unless otherwise approved. Have it installed to the manufacturer's specifications.

Make sure your quote covers these details. For a tank or underground pipe, check whether it includes the relevant vent checks, protection, and tracing. These checks do not cover the full inspection standard.

Source: Virginia DHCD, 13VAC5-63-210, Virginia residential amendments, provisions M1801.1.1/G2425.1.1, P2602.3, P2801.6, and P2903.5; current amendment effective 2024-01-18. Gathered 2026-09-22.

Who is allowed to do the work, and which code applies?

Loudoun requires contractors to hold a valid Virginia contractor license and Loudoun County business license. If a contractor is doing your work, the county recommends naming them as the responsible party on the permit. That lets the county pursue them over code defects.

Check what the licence covers. Virginia's PLB classification covers plumbing systems and water heaters. It does not itself authorise gas piping. A general residential-building classification does not itself authorise plumbing or gas fitting either. If your job includes new gas piping, check that the firm is authorised to do it. You can search Virginia DPOR's licence lookup by business name or licence number. Match the result to the business you are hiring.

The contractor-licensing law gives owners a limited exemption. You may perform or supervise work on no more than one primary residence owned for your own use in a 24-month period. You must still follow the statewide building code. Your hired contractor cannot use that exemption to avoid licensing.

Loudoun's Health Department requires its own contractor licences for well drilling, well-pump installation, and onsite-sewage installation. Do not treat an ordinary plumbing credential as proof of those separate qualifications.

The county currently lists the 2021 Virginia Uniform Statewide Building Code. That includes the 2021 Virginia Residential, Plumbing, and Fuel Gas Codes. It also lists the 2020 National Electrical Code. Its live page says all building applications must comply with the 2021 Virginia code. Use the Virginia editions and amendments if you need to settle a dispute about specifications.

Source: Loudoun County, Residential and Commercial Construction Permits, permit-applicant FAQ, Wells & Onsite Septic Systems, and Building Codes and Regulations, undated; Virginia Board for Contractors, 18VAC50-22-20, effective 2025-09-01; Virginia General Assembly, Code §54.1-1101(A)(7), (C), current text; Virginia DPOR, License Lookup. Gathered 2026-09-22.

What Loudoun County houses are, and what goes wrong in them

Loudoun's draft FFY 2026–2030 Consolidated Plan breaks down housing by age. Its table uses 2016–2020 CHAS data, not a count of houses standing today:

In that dataset, 52% of owner-occupied units were built from 2000 onward. Loudoun has plenty of newer homes alongside older ones. Those figures cannot tell you what pipes a house has. They cannot tell you how old its replacement equipment is either. We found no primary countywide count of polybutylene installations, copper pinhole leaks, or recurring plumbing failures. We cannot infer those from the year a house was built.

If you use Loudoun Water, its troubleshooting advice is more useful than guessing how long a pipe should last:

• White particles in aerators: the utility says calcium building up in the water heater is a possible cause. Another is the heater's plastic dip tube breaking down. Similar-looking debris can need different repairs.
• Black particles: possible sources include rubber seals breaking down or carbon filter cartridges. Where seals are the problem, the utility recommends chloramine-resistant replacement gaskets and O-rings.
• White deposits on showers and kitchenware: dissolved minerals can leave residue. They can also build up in the water heater. Deposits alone do not prove your whole house needs new pipe.

These are the water provider's possible causes, not measured county failure rates. Before agreeing to replace equipment, ask your plumber to identify the debris and where it comes from.

Loudoun Water says the pressure-reducing valve near your main shutoff is there to limit household pressure. That helps limit stress on the pipes. If you have knocking or pressure trouble, include that valve in the checks. Do not assume every symptom starts at the water heater. The age of your subdivision cannot tell you the valve's condition.

Source: Loudoun County Department of Housing and Community Development, Draft FFY 2026–2030 Five-Year Consolidated Plan, Table 30, printed page 96, data vintage 2016–2020 CHAS; draft status retained. Loudoun Water, Drinking Water Quality FAQs and Protect Your Pipes, undated. Gathered 2026-09-22.

A rural well or septic system changes the job

The county says most of rural Loudoun uses private wells and onsite wastewater systems. Town utilities serve incorporated towns and some adjoining areas. Loudoun Water serves designated areas outside the towns. Check which system serves your address before following utility advice.

Limestone geology can affect well water. The Health Department says sediment or changes in clarity after heavy rain may mean surface activity is affecting your well. Bacteria and nitrates may be present without visible warning. It recommends testing for bacteria at least annually. It also recommends testing after rain if you suspect surface activity is affecting your well. You can use the county's geology maps to check whether your property is in a limestone area.

Keep this in mind if a problem seems to come from a fixture but follows a storm. Replacing a tap does not tell you what is happening to the source water. We could not verify a primary-source hardness figure covering both private wells and the different public supplies. We cannot give you a single countywide number.

The county says to have conventional septic tanks pumped at least every five years. Have alternative onsite systems inspected at least annually, or more often if their operating manual requires it. If sewage surfaces or backs into your house, the county says to stop using the system. Have a licensed septic professional assess it. Report the failure to the Health Department.

Health permits have their own published fees:

No fee does not mean no permit. The county treats replacing a component differently from repairing a system. Its component category includes items such as the building sewer, conveyance line, and distribution box. That category applies when the broader construction permit is not required.

The category decides the charge. Knowing a line has failed is not enough to choose between free component replacement and paid system repair. We cannot choose a category without seeing the system. You can confirm with the Health Department at 703-777-0234. Its online fee table gives no effective date. These are the charges it displayed when we gathered the information.

Source: Loudoun County, Utilities; Loudoun County Health Department, Private Water Wells in Limestone Geology Regions FAQ, Wells & Onsite Septic Systems, and Environmental Health Fee Schedule, undated live guidance and fee table. Gathered 2026-09-22.

When a sewer problem belongs to the utility

If you are a Loudoun Water customer, its handbook says to tell the utility about a sewer stoppage. It can check whether the blockage is in the public sewer. The utility handles a public-main stoppage. You need your plumber for a building-sewer stoppage.

Its more specific Sewer Lateral Guidance explains who repairs which part. Your plumber may find a defect between the public right-of-way and the public main. In that case, the utility wants photographs or camera footage with measurements showing the location. Loudoun Water says it will repair its portion at no extra cost to you. You are responsible for defects in your building sewer between the building and public right-of-way.

Locate the defect before agreeing to excavation. A report saying only “bad sewer line” does not tell you whose portion is defective. Make sure the camera record shows the location clearly enough for you and the utility to understand. The guidance lists 571-291-7880 for questions.

A gurgling toilet also needs context. Loudoun Water says sewer-main cleaning can sometimes cause gurgling when cleaning pressure meets inadequate house venting. Gurgling does not prove a collapsed lateral. Record whether utility cleaning was underway. Have persistent symptoms investigated.

Source: Loudoun Water, Customer Handbook, December 2023 edition; Sewer Lateral Guidance and Sewer Cleaning, undated. Gathered 2026-09-22.

What the work is worth

We could not verify county-specific installed prices from a primary source for a water-heater replacement, repipe, drain clearing, or sewer excavation. The published permit charges are government fees, not installed prices. We have not used national cost ranges or regional wages as substitutes for Loudoun job prices.

Ask for a quote that spells out the work. Which equipment and connections does it cover? Does it include gas-piping work? Who handles permits? Who handles inspections? What gets put back after walls are opened or ground is dug up? For a sewer job, attach the defect location. Include the proposed repair limits. For a replacement heater, ask what vent work is included. Check what leak protection it covers too.

Use those details to compare quotes, not calculate a price. Without them, a lower total may simply mean less work. A larger “permit” allowance may include the contractor's paperwork costs. Keep those separate from the county invoice.

Source: Published-fee comparison uses Loudoun County Building and Development's Application Fee Schedule, effective 2022-07-01. No primary-source Loudoun installed-price dataset was verified; quote-comparison suggestions are editorial guidance. Gathered 2026-09-22.