Bathroom Remodel Permit in Brentwood, TN (2026)

Research by DoINeedAPermit Research Team · Updated May 2026

The Short Answer

You need a permit if you're moving fixtures, adding electrical circuits, changing ventilation, converting tub-to-shower, or moving walls. Surface-only work (tile, vanity swap in place, faucet replacement) is exempt.

Brentwood Building Department enforces the 2020 International Building Code with Tennessee amendments, which means full bathroom remodels involving fixture relocation, electrical upgrades, or waterproofing system changes trigger the permit requirement. What makes Brentwood different from neighboring cities like Franklin or Nashville: Brentwood maintains a relatively streamlined plan-review process for residential bathrooms if the scope is clearly defined upfront — submitting a plumbing diagram showing trap arm lengths and vent-stack routing, plus electrical layout with GFCI/AFCI callouts, often gets you over-the-counter approval or quick turnaround rather than multi-week review cycles. The city also requires explicit identification of shower waterproofing systems (cement board + membrane specification) before rough plumbing inspection, which some jurisdictions leave to the contractor's discretion. Brentwood's permit portal allows initial submittal by PDF if you're an owner-builder, but plan review still happens in-person or by phone callback. Karst geology (limestone cavities and sinkhole risk) is noted in the city's flood maps, so if your property sits in a mapped flood zone or karst area, the building department may flag additional drainage or foundation issues during permit review — this is less common in adjacent municipalities.

What happens if you skip the permit (and you needed one)

Brentwood Building Department can issue a stop-work order, halting construction until you file retroactively; fines range from $500–$1,500 depending on scope and your cooperation.
Unpermitted work voids your homeowner's insurance claim for that bathroom if water damage or injury occurs; insurers routinely deny payouts on work completed without permits.
When you sell, the buyer's lender will likely require a permit history or engineer's affidavit ($1,500–$3,000 cost); Brentwood's Title/Disclosure rules flag unpermitted remodels as a material defect.
If a neighbor complains or an inspector spots the work during a routine visit, the city requires removal and rebuilding to code at your expense, potentially $5,000–$15,000 in rework depending on what was hidden.

Brentwood bathroom remodel permits — the key details

Cost and fees: Brentwood's permit fee for a full bathroom remodel typically ranges from $250–$800, calculated as a percentage of the estimated construction cost (usually 1.5–2% of the total project valuation). If you estimate your remodel at $15,000–$25,000, the permit fee will be around $300–$500. Inspection fees are rolled into the permit; there's no separate per-inspection charge. Contractor licensing is also checked — if you're hiring a plumber or electrician, they must hold a valid Tennessee state license (HVAC and plumbing require state licensing; electrical work requires either state licensing or a licensed contractor permit). Brentwood does not require separate mechanical or plumbing permits beyond the main bathroom permit, so you file one permit and coordinate all trades under it. If your project timeline is tight, Brentwood does not offer expedited permit review, so plan for standard 5–10 day turnaround.

Three Brentwood bathroom remodel (full) scenarios

Scenario A

Shower valve and tile replacement in existing tub alcove — Brentwood 1970s colonial, no fixture relocation

Your 1970s colonial has an original cast-iron tub in the master bath. You're replacing the old moen valve with a new pressure-balanced Moen 1224 and re-tiling the entire alcove with new cement board and porcelain tile. No walls are moving, the shower head and drain stay in the same location, and you're not adding or moving any plumbing lines. This work does not require a permit in Brentwood because IRC P2706 and R702.4.2 only mandate permit review when you relocate fixtures or change the waterproofing system assembly fundamentally. Since you're replacing the valve in-place and using standard cement board plus a liquid-applied membrane (the same waterproofing strategy as the original), the building department classifies this as a cosmetic bathroom permit-exempt repair. You do not file with the city. You can hire a plumber or do this yourself; Tennessee does not restrict DIY plumbing if it's repair-and-replace in-kind on an owner-occupied home. However, if the old tile and waterproofing assembly are visibly moldy or deteriorated, and the inspection reveals the original cement board is compromised, you may end up removing more material than expected — at that point, the scope creeps toward a full remodel, and if you've already started work, calling the city becomes awkward. Best practice: inspect and scope carefully before starting, and call Brentwood if you discover unexpected issues.

No permit required | Valve + tile swap in place | Cement board + membrane | $3,000–$5,000 project cost | $0 permit fees

Scenario B

Tub-to-shower conversion with relocated drain and new exhaust duct — Brentwood mid-century ranch, karst-zone property

Your 1950s ranch bathroom has a small soaking tub in the corner; you're tearing it out and installing a walk-in tile shower 4 feet to the left. The drain must be relocated (old trap was 2 feet from the vent stack; new shower pan needs the drain moved closer to the stack to maintain proper slope). You're also adding a new Panasonic WhisperGreen exhaust fan because the original exhaust runs straight into the attic (code violation per IRC M1505.2 — must terminate outside). You'll need a permit for this scope. Your plumbing plan must show the new trap arm length (likely 4–5 feet, within the 6-foot max per IRC P3005.1), vent routing, and the shower pan location with a specification for waterproofing (you're using a pre-fabricated acrylic shower base with cement board walls and a Kerdi-Fix waterproofing membrane system). Your electrical plan shows the new exhaust fan circuit with GFCI protection via a dedicated GFCI breaker. The duct routing is critical: the building inspector will verify the exhaust termination is through an exterior wall with a damper, not into the attic. Since your property is in Brentwood's karst zone (check your tax map or email the building department to confirm), the city may also ask whether your existing septic or sewer tile field is stable, especially if the new drain will route toward the foundation. This is a secondary review — usually just a phone call to confirm no sink holes or known subsidence. Plan review: 1–2 weeks for initial feedback; you'll resubmit once (likely 'Show exhaust duct termination detail' or 'Confirm trap arm length'). Rough plumbing and electrical inspections happen back-to-back. Total timeline: 3–4 weeks from filing to final inspection.

Scenario C

Full gutting with new wall relocation, two new circuits, and AFCI-protected lighting — Brentwood historic-district bathroom, owner-builder

You own a Craftsman bungalow in Brentwood's historic district (check if your property is listed on the National Register or local historic overlay; if so, you may need a Certificate of Appropriateness before permitting). You're completely gutting the bathroom: removing the old lavatory and tub, moving the toilet to the opposite wall (new 3-foot vent stack and 5-foot trap arm required), installing a vessel sink on the original sink wall, and adding a spacious walk-in shower where the old tub was. You're also removing a load-bearing wall (the one separating the bathroom from the hallway) and adding a beam to support the second floor. Two new electrical circuits are needed: one for heated tile flooring under the shower base, one for upgraded lighting with AFCI breakers per IRC E3906 (AFCI protection required for all bathroom lighting circuits as of 2020 IBC adoption). This scope requires a structural engineer's stamp because of the beam, plus full mechanical and electrical plans. You file for a permit in Brentwood and provide: (1) structural engineer's drawing of the beam sizing and removal details; (2) plumbing plan with new vent stack, trap arms, and drain routing; (3) electrical plan showing AFCI breaker locations and heated-floor mat thermostat wiring; (4) shower waterproofing spec (likely a pre-fabricated shower system given complexity, e.g., Schluter Kerdi board system or equivalent); (5) if in historic district, a completed historic-design review form (Brentwood's planning department reviews this alongside building permits). Plan review: 2–3 weeks because of structural and historic components. If historic, you may get comments about tile color, fixture finishes, or wall framing visibility (some historic districts care about interior character). You'll schedule rough inspections in sequence: framing (for the beam and wall removal), rough plumbing, rough electrical, rough HVAC (if relocating vent), then drywall, then final plumbing/electrical/mechanical. Total timeline: 5–6 weeks from filing to final inspection. The owner-builder exemption applies (Tennessee law allows owner-builders on owner-occupied homes), but you'll still need to hire licensed electricians for the AFCI circuits and likely a licensed plumber for drain relocation; homeowner labor is allowed for demolition, framing, drywall, and tile.

Every project is different.

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Waterproofing and shower assembly — why Brentwood inspectors care about details

Lead paint consideration: If your Brentwood home was built before 1978, the shower walls may contain lead paint in the original plaster or drywall. Tennessee follows EPA RRP (Renovation, Repair, and Painting) Rule, which requires certified lead-safe contractors for renovations disturbing lead paint. If you're tearing out the old shower and walls, you must assume lead is present (it likely is). You can hire a lead-certified contractor or request a lead inspection and abatement before you start. This is separate from the building permit but must be done before work begins — the city won't inspect until you can confirm lead-safe work practices. Cost: $500–$1,500 for a lead inspection; abatement or certified renovation adds $1,000–$3,000 depending on square footage.

Exhaust fan ducting and ventilation — Brentwood code enforcement specifics

CFM sizing rule: A bathroom exhaust fan must move at least 50 CFM (cubic feet per minute) per IRC M1505.1; if the bathroom is over 100 square feet, it's 1 CFM per square foot. A typical master bath (60–80 sq ft) needs a 50–80 CFM fan. Oversizing (e.g., a 150 CFM fan) is fine and actually desirable for humid climates, but make sure your ductwork is sized accordingly — a 50 CFM fan can use 3-inch duct; a 100+ CFM fan needs 4-inch or larger duct to avoid excessive noise and restriction. Brentwood does not require CFM calculations on the permit plan, but the inspector may ask during rough inspection if the fan size seems undersized for the duct diameter. Panasonic WhisperGreen, Broan, and Nutone make reliable residential bathroom fans in the 50–150 CFM range; avoid ultra-cheap big-box fans that are noisy and fail quickly.

City of Brentwood Building Department
5300 Maryland Way, Brentwood, TN 37027
Phone: (615) 371-0060 | https://www.brentwood-tn.org/ (check city website for permit portal link)
Monday–Friday, 8:00 AM – 5:00 PM (closed holidays)

Common questions

Do I need a permit to replace my bathroom vanity and faucet in Brentwood?

No, if the vanity and faucet are installed in the same location as the original fixture. This is a surface-level swap exempt from permitting. However, if you're moving the vanity to a new wall location, that's a plumbing fixture relocation and requires a permit because the drain must be re-routed and inspected for proper slope and vent stack distance per IRC P3005.1. Call the Brentwood Building Department if you're unsure about your specific scope.

What if my bathroom is in a 1960s Brentwood home with asbestos drywall or flooring?

Homes built before 1980 may contain asbestos in drywall, joint compound, flooring, or pipe insulation. Tennessee law requires that asbestos-containing material (ACM) be identified and safely removed by a licensed abatement contractor before demolition. This is separate from the building permit process, but must be completed before work begins. Get an asbestos survey ($300–$600); if ACM is found, hire a licensed abatement firm ($1,500–$5,000 depending on quantity). Do not disturb or remove ACM yourself — it's illegal and dangerous.

Can I do the bathroom remodel myself, or do I need to hire contractors in Brentwood?

Tennessee law allows owner-builders to perform work on owner-occupied homes without a contractor's license, but plumbing and electrical work require state-licensed contractors (or supervisor permits, which are rare). You can do demolition, framing, drywall, tiling, and painting yourself; you must hire a Tennessee-licensed plumber for any drain relocation or new rough-in, and a licensed electrician for new circuits or AFCI/GFCI installation. The Brentwood Building Department will verify contractor licenses during permit review and inspections.

How long does a full bathroom remodel permit take in Brentwood?

Simple remodels (surface-only, no fixture relocation) are exempt and need no permit. Fixture-relocation remodels typically take 5–10 days for initial plan review, plus 3–5 days for resubmittals if comments are needed. Once approved, rough and final inspections add 2–3 weeks depending on your contractor's schedule. Total time from filing to final inspection: 3–5 weeks for a straightforward remodel, 5–6 weeks if walls are moved or historic review is required.

What's the difference between a bathroom permit and a mechanical or plumbing permit in Brentwood?

Brentwood issues a single 'bathroom remodel' or 'residential interior alteration' permit that covers plumbing, electrical, and mechanical work for the bathroom. You don't file three separate permits. The building department coordinates all three trades under one permit number, and you schedule inspections in sequence (rough plumbing, rough electrical, rough HVAC, framing/drywall, final). This simplifies permitting and inspection logistics compared to jurisdictions that separate trades.

Does Brentwood require a Certificate of Appropriateness for a historic-district bathroom remodel?

If your home is in Brentwood's local historic district or on the National Register of Historic Places, yes — the Planning Department must approve the design before building permits are issued. This is called a Certificate of Appropriateness (COA) and focuses on exterior visibility and character. Interior bathrooms are usually approved without fuss, but if your remodel affects visible exterior features (roofline, fenestration, addition), the Planning Department may comment on materials, colors, or scale. Coordinate with Planning early; their review adds 1–2 weeks. Check the City of Brentwood website or call Planning at (615) 371-0060 to confirm whether your property is in a historic district.

What does 'trap arm length' mean, and why does Brentwood's inspector care?

The trap arm is the horizontal pipe section between your fixture (toilet, sink, or shower drain) and the main vent stack. IRC P3005.1 limits trap arm length to 6 feet for a standard bathroom fixture — this ensures waste drains properly (slope 1/4 inch per foot minimum) without air-lock or slow drain. If you relocate a fixture more than 6 feet from the vent stack, you either need a longer vent stack, a separate vent for the new fixture, or a cheater vent (air admittance valve). Brentwood inspectors will check trap arm length during rough plumbing inspection to ensure code compliance. Your plumber should know this rule and plan accordingly.

Do I need separate GFCI outlets and AFCI breakers for a new bathroom in Brentwood?

Yes. IRC E3902 requires all bathroom receptacles (outlets) within 6 feet of a sink or tub to be protected by GFCI (ground-fault circuit interrupter). This can be done via a GFCI outlet or a GFCI breaker. Additionally, per 2020 IBC adopted in Tennessee, all bathroom branch circuits (including lighting circuits) must be AFCI-protected via an AFCI breaker. Brentwood's electrical inspector will verify GFCI protection at all outlets and AFCI protection on the main bathroom circuit. This is a common code requirement in modern bathroom permits.

What if I discover mold or structural damage during my bathroom demo — can I still proceed?

If you uncover mold, black mold growth, or structural rot/decay, stop work immediately and call the Brentwood Building Department or a licensed mold remediation company. Mold remediation must be done before continuing the remodel because it poses health and safety risks. Similarly, if you discover rotted framing, water-damaged joists, or structural issues, your contractor should notify the building department — the permit inspector will assess whether the damage can be repaired as part of the remodel or requires additional structural work. Do not cover up mold or rot with new materials; the inspector will discover it during final inspection and require removal and remediation, adding weeks and cost.

How much does a Brentwood bathroom remodel permit cost?

Permit fees are typically 1.5–2% of the estimated project cost. For a $15,000–$25,000 remodel, expect a permit fee of $250–$500. For a larger remodel with structural work ($35,000–$55,000), fees are $600–$900. If you hire a structural engineer for beam or wall relocation, add $800–$2,000 for the engineer's stamp. Inspection fees are included in the permit fee; there's no additional charge per inspection. Brentwood does not offer expedited permit review, so plan for standard 5–10 day turnaround at no additional cost.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current bathroom remodel (full) permit requirements with the City of Brentwood Building Department before starting your project.

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