Menu
(773) 681-5011 Get matched

Basement Bathroom Additions in Chicago

Basement bathroom with a glass shower, vanity and a high window

A basement bathroom adds a room where the plumbing has the hardest job. When basement fixtures sit below the house drain, waste has to be pumped up rather than drained out. Angi puts a professionally installed sewage ejector pump at $850 to $3,500, and that is only one line in the project. Your own price depends on what is already in the floor, so tell us about the project and we will match you with up to three independent licensed remodelers who can give you a written scope and price to compare.

Updated October 21, 2026. Every figure and code reference links to its source at the end of this page. This is general information, not legal or engineering advice.

Gravity or pump: the first decision

A toilet, sink or shower drains by gravity only if its drain can slope down into the sewer line. The Chicago Plumbing Code says building drains that cannot discharge to the sewer by gravity must run into a tightly covered, vented sump, with automatic pumping equipment lifting the liquid into the building drainage system (section 18-29-712.1). In plain terms, that is a sewage ejector pit set into the basement floor.

Ask every remodeler which system they are pricing, where the pit and its access cover will be, and who services the pump later. A pump runs on electricity, so ask what happens during a power outage.

Permit guide (4 WSFU)

Flooding and sewer backup

A new basement bathroom puts a toilet at the lowest point of the house. The City of Chicago’s Department of Water Management says that during intense storms, sewer mains fill and push water into basements through private drains, and that nobody can promise you will never flood. WBEZ describes the common fixes for Chicago homes: a check or backwater valve, a standpipe in the floor drain, or an overhead sewer, which pumps basement wastewater up to a pipe at the basement ceiling or first floor.

The Chicago Plumbing Code limits where backwater valves can be used: only for fixtures whose overflow rim is below the next upstream manhole in the public sewer (18-29-715.1). So the right answer depends on your block and your pipes. Tell each remodeler about any past backup, and ask how the new bathroom, the floor drain and any backwater valve will work together. The City also recommends disconnecting roof downspouts from the drain system where practical.

Ceiling height

Ceiling height is where many basement plans run into trouble, because ducts, beams and pipes hang low. The City’s minimum standards for existing residential buildings (14X-4-402.1) set a clear ceiling height of 7 feet for bathrooms, allow 6 feet 8 inches within dwelling units, and allow pipes, ducts or beams covering up to 25% of the ceiling to hang down to 6 feet. Which rule applies to your basement, and whether a new bathroom counts as an alteration under a different code, is something to confirm with the remodeler and the City. Measure your lowest point before you sketch a layout.

Other rules to ask about

Habitable space and egress. A bathroom is not a bedroom. If your plan also adds a bedroom or finished living space, ask each remodeler which City rules for habitable basement rooms apply, including windows and exits. We do not summarize those rules here.

Ventilation and electrical. The Chicago Building Code calls for a mechanical exhaust system in bathrooms, and the NKBA guidelines suggest a fan rated at 60 cubic feet per minute or more and ground-fault (GFCI) protection for all bathroom outlets. A licensed electrical contractor is needed for new circuits.

Two-flats and shared basements. In a two-flat, ask who owns or uses the basement and whether the new drain ties into plumbing that serves both units.

Permits and licenses in Chicago

Adding a bathroom needs a City of Chicago permit. The Express Permit Program lists adding a private bathroom as 4 water supply fixture units, under its limit of 5, but it is not open to work in a space that has never been legally occupied or to converting unheated space into living space. An unfinished basement may therefore fall outside the Express path. Ask the remodeler or the Department of Buildings which permit applies. Adding or moving walls or doors needs drawings from an Illinois-licensed architect or structural engineer.

Chicago requires a licensed and bonded plumbing contractor for most plumbing work. The one exception is an owner, occupant or lessee of a detached single-family residence doing the work personally, and that exception does not let anyone hire an unlicensed plumber. Illinois law is similar: plumbing is done only by licensed plumbers, with a narrow exception for owner-occupants of single-family homes. Electrical work needs a licensed electrical contractor and the project needs a licensed general contractor, with limited owner exceptions. The remodelers we match you with are independent companies, so verify each license.

Houses, two-flats and condos

If you own a house or two-flat, see the neighborhood notes for Portage Park and North Center. Condo basements and garden units have their own association rules, covered in remodeling a condo bathroom in Chicago. For costs beyond the pump, see how much a bathroom remodel costs in Chicago, or return to all services.

How to get a fair comparison

  1. Ask for a written scope and price from each remodeler that names the drainage method, the pit and pump, venting, electrical, permit and an allowance for what the slab reveals.
  2. Ask who holds the permit and which licensed plumbing and electrical contractors will do the work.
  3. Share your flood history and your measured ceiling height with every remodeler.
  4. Read the contract. Illinois law requires a written contract for home remodeling work over $1,000.

Frequently asked questions

Do I need a sewage ejector pump for a basement bathroom?

If the fixtures sit below where the house drain can accept gravity flow, the Chicago Plumbing Code requires a covered, vented sump with automatic pumping equipment. A licensed plumber has to confirm what your house needs.

How much does an ejector pump cost?

Angi puts professional installation of a sewage ejector pump at $850 to $3,500, with an average of $2,300. That is only one part of a basement bathroom project, and breaking the slab, venting and electrical work are priced separately.

Do I need a permit to add a basement bathroom in Chicago?

Yes. The Express Permit Program lists adding a private bathroom as 4 water supply fixture units, but it does not cover space that was never legally occupied. Ask the remodeler or the Department of Buildings which permit applies to your basement.

Does the plumber have to be licensed?

In Chicago, a licensed and bonded plumbing contractor is required for most plumbing work. The only exception is an owner or occupant of a detached single-family residence doing the work personally, and that exception does not let you hire an unlicensed plumber.

Will a basement bathroom make my basement flood?

It does not cause flooding, but it puts a toilet at the lowest point of the house. Chicago's Department of Water Management says storms can push water into basements through private drains. Ask how the new bathroom, floor drain and any backwater valve will work together.

How high does a basement ceiling need to be?

The City's minimum standards for existing residential buildings set 7 feet for bathrooms, allow 6 feet 8 inches within dwelling units, and allow obstructions over up to 25% of the ceiling at 6 feet. Confirm which rule applies to your project before you plan.

Does a basement bathroom need an egress window?

A bathroom is not a bedroom, and we do not summarize the habitable-basement rules here. If you are also adding a bedroom or living space, ask each remodeler which City rules for windows and exits apply.

Is this service a contractor?

No. Chicago Bathroom Remodeling Experts is a free referral service. We do not remodel, plumb or do electrical work. We connect you with independent, licensed remodelers, who are responsible for their own licenses, permits, insurance and contracts.

Sources

Related

Get matched with licensed Chicago remodelers

Tell us about your bathroom and we will connect you with independent, licensed Chicago remodelers so you can compare a written scope and price for the same work.

Permit guide (4 WSFU)

Free and no obligation. We only share your request with the remodelers you are matched with.

Get matched