When planning a bathroom remodel, most homeowners focus on the exciting parts — the custom tile patterns, the elegant vanity, the perfectly placed lighting. But before a single tile is set, there’s another essential step that shapes the quality and longevity of your project: securing the right permits.
Permits are more than just paperwork. They’re the assurance that your remodel meets the structural, plumbing, and electrical safety standards set by the City of St. Louis, St. Louis County, or your local municipality. They safeguard your investment, protect your home’s resale value, and ensure that every detail — visible and hidden — is built to last.
At Morganco Design Build, we’ve navigated the permit process for decades. As third-generation builders, we see permits not as a hurdle, but as a foundation — a step that confirms we’re delivering craftsmanship that stands the test of time.
Why Bathroom Remodeling Permits Matter
Protecting Your Investment and Home Value
A bathroom remodel is a significant investment, often involving structural work, plumbing rerouting, or electrical upgrades. Without proper permits, those improvements can become a liability. If you decide to sell, unpermitted work may cause delays in closing or force costly tear-outs to bring the space up to code. By securing permits from the start, you ensure your remodel is recognized as safe, legal, and up to professional standards — giving buyers, appraisers, and inspectors confidence in the work.
Meeting St. Louis County and City Building Codes
Each jurisdiction in the Greater St. Louis area has its own building codes and permit requirements. For example, moving a bathroom wall in Clayton requires different documentation than adding a vent fan in Kirkwood. Building codes are designed to ensure safety — from proper electrical grounding near water sources to plumbing venting that prevents sewer gas backflow. As builders, we see these codes not as restrictions, but as a benchmark for quality craftsmanship.
Avoiding Costly Delays and Penalties
Working without permits can stop your project in its tracks. Municipal inspectors have the authority to halt unpermitted work, issue fines, and require demolition of completed work. In our experience, a well-prepared permit application keeps the project moving smoothly. We plan every detail — from detailed drawings to material specifications — so the approval process is efficient, keeping your remodel on schedule.
Common Bathroom Remodel Work That Requires a Permit
Not every bathroom update requires a permit — but the moment you make changes that affect a home’s structure, plumbing, electrical system, or ventilation, local building departments get involved. In St. Louis, these rules exist to ensure that every hidden component of your remodel is as durable and safe as the beautiful finishes you see on the surface.
Structural Changes (Walls, Doors, and Windows)
If your remodel involves moving or removing a wall — even a non-load-bearing one — you’ll likely need a permit. The same applies to creating a new doorway, enlarging a window for more natural light, or changing the room’s layout in a way that affects the building’s framing.
For example, in a recent Webster Groves project, we reconfigured a cramped bathroom by removing an interior wall to create a larger shower space. Because that wall carried plumbing supply lines, we coordinated the structural changes and plumbing modifications under the same permit application. The result: a smooth inspection process and a perfectly proportioned, code-compliant space.
Plumbing Modifications and Fixture Relocations
Anytime you move a toilet, shower, or sink, you’re altering the plumbing system. Even a few inches of change can require new water supply lines or drain placements, both of which must meet code to prevent leaks, backflow, or pressure issues.
In Clayton, for example, relocating a shower to the opposite side of the bathroom triggers a plumbing permit and inspection. This ensures that proper slope and venting are in place, and that water pressure is balanced for optimal performance.
Electrical Upgrades and Lighting Changes
Bathrooms demand special attention to electrical safety because of their high moisture environment. Permits are required for adding or moving outlets (especially GFCI outlets), rewiring light fixtures, or installing new heated flooring systems.
In a recent Ladue remodel, our team added LED recessed lighting, a lighted vanity mirror, and radiant heat flooring — all requiring electrical permits. The inspections confirmed that wiring was moisture-protected and breakers were appropriately rated, ensuring years of safe operation.
Ventilation, HVAC, and Waterproofing Systems
Proper ventilation prevents mold growth and maintains indoor air quality — a necessity in bathrooms. Installing or upgrading a vent fan that exhausts to the exterior requires permitting in most St. Louis jurisdictions. If you’re adding ductwork or adjusting existing HVAC systems, an additional mechanical permit may be required.
We also treat waterproofing as seriously as ventilation. While not every waterproofing upgrade requires a permit, when it’s part of a larger permitted remodel, inspectors will check to confirm moisture barriers are correctly installed before tile work begins
The Bathroom Remodeling Permit Process in Greater St. Louis
Every municipality in the St. Louis area handles permits slightly differently, but the process follows a general sequence: confirm jurisdiction, prepare and submit plans, and pass inspections at specific stages of construction. Knowing these steps in advance helps prevent delays and ensures that each stage of your remodel meets the highest standard of safety and craftsmanship.
Determining Jurisdiction – City, County, or Municipality
Your first step is identifying which authority issues permits for your home. A homeowner in Kirkwood will apply through the city’s Building Department, while a property in unincorporated St. Louis County will go through the county’s Public Works office. Each has its own forms, fees, and requirements — and in some cases, even neighboring streets can fall under different jurisdictions.
At Morganco Design Build, we verify this before design work begins. This early step avoids last-minute surprises and allows us to tailor plans to the exact code requirements of your area.
Submitting Plans and Drawings
Once your remodel design is finalized, we prepare detailed plans that meet your jurisdiction’s submittal standards. For a bathroom remodel, this often includes:
A floor plan showing existing and proposed layouts
Plumbing and electrical diagrams
Material specifications for fixtures and finishes
Ventilation details, including fan size and exhaust route
These aren’t just basic sketches. Our drawings are precise and scaled, with every measurement and material clearly labeled — the same level of documentation we use on high-end custom builds. This ensures reviewers can quickly verify compliance with local codes, speeding up the approval process.
Inspection Stages and What Inspectors Look For
Once your permit is approved and work begins, the building department will schedule inspections at specific milestones. In a typical bathroom remodel, these include:
Rough-in Plumbing Inspection – Ensures water supply and drainage lines are correctly installed before walls are closed.
Rough-in Electrical Inspection – Verifies wiring, outlets, and breaker connections are code-compliant.
Framing Inspection (if applicable) – Confirms any structural changes meet engineering and safety standards.
Insulation and Vapor Barrier Check – For bathrooms with exterior walls, inspectors confirm insulation and moisture barriers are correctly installed.
Final Inspection – Reviews the completed work for safety, functionality, and code compliance.
Because we coordinate directly with inspectors, our projects rarely face delays at this stage. Our crews understand exactly what inspectors expect to see, and we prepare each phase of work to exceed those standards — not just meet them.
Costs and Timelines for Bathroom Remodel Permits
Bathroom remodeling permits are an investment in your project’s safety, value, and long-term performance. While the cost is a fraction of the overall remodel budget, it’s important to understand how fees are calculated and how they influence the schedule.
Typical Permit Fees in St. Louis
Permit costs vary depending on the jurisdiction, scope of work, and whether structural, plumbing, mechanical, or electrical permits are required individually. In the Greater St. Louis area, you can expect:
Basic remodel permits (minor plumbing/electrical updates, no structural changes): $75–$200
Comprehensive remodel permits (structural modifications, multiple trades involved): $200–$500
Separate trade permits – Some municipalities require individual permits for plumbing, electrical, or HVAC work, each with its own fee, typically $50–$150 per trade.
For example, in a University City remodel involving a new walk-in shower, relocated toilet, and updated lighting, the combined permit fees totaled around $350. That covered all necessary trade permits and final inspections.
How Permits Affect Your Project Timeline
Permit reviews can take anywhere from a few business days to several weeks depending on your municipality and the complexity of the remodel.
Straightforward bathroom updates (no structural changes) are often approved within 3–5 business days.
Full bathroom overhauls involving multiple trades or structural adjustments may require 1–3 weeks for review, especially if plan revisions are requested.
The most efficient remodels are the ones where permit applications are submitted early in the design process. At Morganco Design Build, we prepare permit-ready plans alongside your design selections so that while you’re finalizing materials, your permits are already in review. This parallel process means the approval window doesn’t add unnecessary delays to your start date.
We also schedule inspections as soon as each stage is ready — never after the fact — so the project moves seamlessly from one phase to the next.
Work That Typically Does Not Require a Permit
Not every update to your bathroom needs to go through the permitting process. In St. Louis, purely cosmetic improvements — changes that don’t alter the structure, plumbing, or electrical systems — can usually be completed without formal approvals. These projects still demand the same level of craftsmanship, but they won’t require city or county inspectors to sign off.
Cosmetic Updates and Surface-Level Changes
Examples of no-permit work include:
Replacing an existing vanity without moving plumbing connections
Updating faucets or showerheads without altering supply lines
Installing new tile or flooring over an existing subfloor
Painting walls or cabinets
Swapping out mirrors, towel bars, or light fixtures (if no rewiring is involved)
Adding storage solutions such as shelves or freestanding cabinetry
These upgrades can transform the look and feel of a bathroom without touching the underlying systems that trigger permits.
How Morganco Streamlines the Permit Process
While permits can seem like a hurdle, in skilled hands they become an integrated, predictable part of the remodeling process. At Morganco Design Build, our team has spent decades refining a system that takes the burden off homeowners while ensuring every aspect of the remodel meets — and often exceeds — St. Louis code requirements.
Detailed Planning to Avoid Delays
Every successful remodel starts with precise, complete plans. We develop construction drawings that go beyond what most contractors submit — including structural details, exact fixture specifications, and finish materials. By anticipating the questions plan reviewers are likely to ask, we minimize back-and-forth requests for clarification, which keeps your project moving forward.
In-House Expertise in Local Building Codes
We’ve worked in historic neighborhoods like Lafayette Square, contemporary homes in Chesterfield, and everything in between. This range of experience means we know the nuances of each municipality’s permitting requirements — from the special considerations for historic districts to the specific plumbing venting rules in St. Louis County. We use that knowledge to design smarter from the start, avoiding revisions that cost time and money.
Coordinating with Inspectors for a Smooth Build
Our relationship with local inspectors is built on mutual respect and trust earned through consistent, high-quality work. We schedule inspections at the ideal time — never too early, never after the fact — so that the inspector sees each stage exactly as it should be. When minor adjustments are needed, we handle them immediately on-site, preventing delays and ensuring the project moves seamlessly into the next phase.
For homeowners, this means you don’t have to worry about phone calls, forms, or scheduling with the city. We manage it all, so you can focus on design decisions and look forward to the finished space.
A bathroom remodel isn’t just about beauty — it’s about building a space that functions flawlessly, stands up to daily use, and enhances your home’s value for years to come. Permits play a crucial role in that process. They confirm that every hidden pipe, wire, and structural element meets the same high standard as the finishes you see every day.
At Morganco Design Build, we view permitting as part of our craftsmanship. It’s not a bureaucratic step to get past; it’s an opportunity to prove — on paper and in practice — that your bathroom is built to last. From detailed plan preparation to coordinating inspections, we handle the entire process so you can enjoy a smooth, stress-free remodel.
Whether you’re reimagining a master suite in Town and Country, upgrading a historic bath in Soulard, or modernizing a guest bath in Ballwin, our team treats each project with the care and precision of a third-generation builder who takes personal pride in every detail. The result is more than a finished room — it’s a space worthy of your home’s story, built to serve for decades to come. Contact us today!