City of Boulder
Plumber Boulder CO
Boulder treats water heaters as mechanical permits. Clearing a stoppage or swapping a toilet without moving pipes can be exempt. Replacing a concealed drain is new work and needs a permit.
What is exempt
The city's permit page says you may stop a leak or clear a stoppage in drains, water, soil, waste, or vent piping without turning that into a permit, unless a concealed trap or pipe has to be removed and replaced. Replacing that concealed pipe is new work. Replacing a toilet is exempt if you do not rearrange valves or pipes. Water heaters, furnaces, and fireplaces are listed under mechanical permits. Plumbing is its own permit. Right-of-way permits are separate for wet utilities and for dry utilities. A fixture-count form is required when the number, type, or location of fixtures changes, including fixtures on an existing rough-in, and it must count every fixture on the water meter, including a detached building.
Not a fee quote
The city publishes a 2026 fee schedule. This guide does not copy those dollar amounts into a repair price. Work started without a permit can be assessed a higher fee under that schedule. Ask the city. Boulder is not Louisville, Lafayette, or Aurora. A remodel that adds a bathroom needs the fixture count. A clog that you clear without new pipe may be the exemption.
Questions to settle first
Does Boulder require a permit to replace a water heater?
The permit list puts water heaters, furnaces, and fireplaces under mechanical permits. That is not the plumbing exemption for clearing a stoppage. Ask whether your replacement is the mechanical permit. Do not use Aurora's same-day rule. Right-of-way work, if you open a street, is another permit.
Can I replace a toilet without a permit?
The city says yes if you do not replace or rearrange valves or pipes. If the flange or the shutoff has to be redone, you are past that sentence. Concealed drain replacement is new work and needs a permit and an inspection.
What is the fixture-count form for?
Any project that changes the number, type, or location of fixtures, including a fixture set on an existing rough-in. Count every fixture on that water meter, even in a detached building. The city uses it for meter and plant-investment questions. It is not a sewer-ownership map.
A slow drain is drain cleaning until a camera shows a broken sewer line. A tank swap is water heater replacement. Confirm the permit office and the utility for this address before the work is closed up.
