Bathroom Remodeling in Longmont, CO

Bathroom remodeling in Longmont is small-footprint work with a lot of code packed into it. Plumbing, venting, electrical, waterproofing, and sometimes gas appliances all meet in one room, and Longmont’s Building Services treats changes to those systems as permit work. Our crew plans Longmont bathrooms around the city’s published clearances, its wiring guidance, its asbestos testing threshold, and the licensing rules that apply to plumbers and electricians.

When a Longmont Bathroom Needs a Permit

Longmont requires a building permit for any alteration inside an existing building, any change to the electrical, gas, mechanical, or plumbing systems, and any repair involving structural members. The city’s examples list interior remodels, drywall installation or removal, insulation, window replacement, water heaters, and relocating electrical receptacles.

In a bathroom, that usually means a permit as soon as the tub comes out, a drain moves, a wall opens, or a fan and new circuit go in. The city does not publish a list of cosmetic bathroom work that is exempt, and it directs owners with questions to Building Services at the Development Services Center.

We define the bathroom scope in writing before anything is removed. The permit application should describe the real work, including existing and proposed layouts, so the inspector is reviewing the bathroom that will actually be built.

Shower and Toilet Dimensions in the City’s Guidance

Longmont’s Basement Finish Guide includes a bathroom section that is useful for any bathroom in the house. It calls for at least 21 inches of clear space in front of a toilet and 15 inches from the toilet’s centerline to any sidewall or other obstruction. Those two numbers decide whether a toilet can stay where it is when a vanity gets wider or a shower wall moves.

For showers, the guide lists a minimum inside area of 900 square inches, room to contain a 30-inch circle, and non-absorbent wall finishes to 70 inches above the drain. That matters when a tub is converted to a walk-in shower or a new shower is carved from a closet.

The guide was published before Longmont moved to the 2024 International Codes on July 1, 2026, so we confirm current figures with Building Services during design. The practical point stays the same: layout decisions need to respect clearances before tile and glass are ordered.

Exhaust Fans and Moisture Control

The same city guidance requires a ventilation fan in any bathroom with a tub or shower and in bathrooms with windows that do not open. The fan must be vented to the exterior of the building using listed vent pipe. A fan that dumps into an attic or a joist bay does not meet that description.

Moisture is where bathroom remodels fail over time, so we treat ventilation and waterproofing as one system. The fan route, the duct termination, the shower waterproofing, and the finish materials above the drain line all get planned together.

Where the fan route crosses framing or requires a new roof or wall penetration, we show it on the drawings. That keeps the rough mechanical inspection clean and avoids reworking a ceiling after drywall.

Bathroom Circuits Under the Longmont Wiring Guide

Longmont’s Residential Wiring Guide requires at least one 20-amp circuit for bathroom receptacle outlets. At least one receptacle must sit within 36 inches of the outside edge of each basin, on a wall adjacent to the basin. Bathroom receptacles must be GFCI-protected, and so must hydro-massage tubs.

The guide also states that electrical panels are not permitted in bathrooms. In older homes where a panel was placed in a space that later became a bathroom, or where a remodel expands a bathroom into a closet that holds a panel, that rule changes the plan.

We lay out vanity lighting, heated floors, fan circuits, and receptacles together so the rough electrical inspection matches the finished room. Electrical contractors in Longmont pull their own permits under State of Colorado requirements, so the electrical scope is coordinated from the start.

Water Heaters, Gas Appliances, and Enclosures

Water heater replacement is on Longmont’s permit list. In bathroom projects, the more important rule is placement. The city’s guidance says fuel-burning furnaces and water heaters cannot be located in a bathroom unless they are in a dedicated enclosure where all combustion air comes directly from outdoors, with a weather-stripped solid door and an approved self-closing device.

That comes up when a bathroom is expanded into a utility space or a basement bath is built next to the mechanical room. The same guidance calls for 30 inches of clear working space in front of furnaces and water heaters and outside combustion air for fuel-burning appliances.

We check mechanical locations before the bathroom layout is finalized, so the design does not depend on moving equipment that cannot legally sit in the new room.

Asbestos Testing and Licensed Plumbing

Longmont requires asbestos testing on single-family homes when disturbance exceeds 50 linear feet on pipes, 32 square feet on other surfaces, or the volume of a 55-gallon drum. Bathroom demolition often removes tile, backer board, drywall, flooring, and old pipe insulation, so testing is part of planning, not an afterthought.

Licensing is the other half. Anyone contracting in Longmont needs a Longmont contractor license, and the city does not offer reciprocity. Plumbers must register with the State of Colorado and with the Division of Building Inspection, and electricians and plumbers submit a current State of Colorado master’s license and contractor’s license. Longmont will not inspect subcontracted work done by an unlicensed subcontractor.

Even a homeowner acting as general contractor on a primary residence must use Longmont-licensed subcontractors for plumbing, electrical, HVAC, and framing work.

How We Sequence a Longmont Bathroom Remodel

We start with layout and clearances, then confirm fan routing, circuits, and any nearby gas appliances. Asbestos testing is scheduled for the materials coming out. The permit application goes in with the scope, existing and proposed layouts, and the licensed trades listed. Plans are reviewed in the order received, and the approved set stays on site for every inspection.

Once work begins, our crew demolishes in line with the testing results, then completes framing changes, rough plumbing, rough electrical, and fan ducting for the rough inspection. Inspection requests go in before 4:00 pm for next-business-day visits. After approval come insulation where needed, backer board, waterproofing, tile, fixtures, trim, and the final inspection.

Common Questions

Does replacing a tub with a shower need a permit in Longmont?
In most cases, yes. Longmont requires a permit for any alteration and any change to plumbing, electrical, or mechanical systems. Moving a drain, changing a valve, or adding a fan circuit falls within that.

What shower size does Longmont’s guidance list?
The city’s Basement Finish Guide lists a minimum inside area of 900 square inches, enough to contain a 30-inch circle, with non-absorbent finishes to 70 inches above the drain. Confirm current figures with Building Services under the 2024 codes.

Is a bathroom exhaust fan required?
The city’s guidance requires a fan in bathrooms with a tub or shower and in bathrooms with windows that do not open. It must vent to the exterior using listed vent pipe.

Does my plumber need a Longmont license?
Yes. Plumbers must register with the State of Colorado and with Longmont’s Division of Building Inspection, and Longmont will not inspect work done by an unlicensed subcontractor.

Talk to Us About Your Project

Tell us what you want to change in the bathroom, including the tub or shower, vanity, toilet location, lighting, and ventilation. We handle the Longmont permit process and coordinate layout, testing, licensed trades, inspections, and closeout.