Adding a bathroom to a house can sound like a project that demands more square footage. But sometimes the space is already there — hiding in a closet, a storage room, an oversized bathroom, or another part of the floor plan that could be working harder for you.
At Century City Baths, we’ve spent years helping Chicagoland homeowners discover usable square footage they didn’t know they had. In a region full of bungalows, two-flats, Victorians, split-levels, and mid-century ranches, “no room for another bathroom” is rarely the final answer. More often, it’s a matter of looking at the floor plan with fresh eyes.
Here are seven of our favorite approaches to finding space for a bathroom inside the home — no addition required.
1. The Oversized Bathroom That Became Two
One of the most common opportunities we see is a primary bathroom that’s larger than it needs to be. Homes built in the late ’90s and early 2000s often feature enormous master baths with a corner soaking tub nobody uses, acres of tile, and a dead zone of floor space between fixtures.
By reconfiguring the layout — swapping a rarely used garden tub for a well-designed walk-in shower and tightening up the vanity wall — it’s often possible to carve out a second bathroom that serves adjacent bedrooms or a hallway.
Why it works in Chicagoland: Suburban homes in Naperville, Schaumburg, and Arlington Heights frequently have generous primary suites paired with a single hall bath serving two or three bedrooms. Rebalancing that square footage improves daily life far more than an oversized tub ever did.
2. The Linen Closet Turned Powder Room
A half bath needs surprisingly little space. With a compact toilet, a wall-mounted or corner sink, and a door that swings out rather than in, a powder room can fit into roughly 11 to 18 square feet.
Deep linen closets, coat closets near an entry, or a closet under a staircase are prime candidates — particularly when they back up to an existing wet wall, which keeps plumbing costs down.
What to watch for: You’ll need adequate clearance in front of the toilet (typically 21 inches minimum, with 24 inches preferred) and proper ventilation. In older Chicago homes with cast iron drain lines, we’ll evaluate whether a macerating or upflush system makes more sense than cutting into existing stacks.
3. The Basement Storage Room Becomes a Full Bath
Chicagoland basements are full of potential. Whether it’s a Berwyn bungalow with a partially finished lower level or a Hinsdale colonial with a sprawling unfinished basement, there’s usually a storage area, a former coal room, or an awkward corner near the utility closet that can become a full bathroom.
Adding a basement bath instantly makes the lower level usable as a guest suite, a teen hangout, an in-law space, or a rental unit.
The technical reality: Basement bathrooms often sit below the sewer line, which means an ejector pit or upflush toilet system. It’s an added cost, but it’s a well-established solution — and far cheaper than building an addition. We also pay close attention to moisture management, proper vapor barriers, and insulation, which matter enormously in our freeze-thaw climate.
4. The Hallway Nook Nobody Used
Many homes have dead circulation space — a wide hallway, an alcove, a landing that’s larger than it needs to be, or a built-in desk nook from a previous renovation. These areas are often perfect for a powder room, especially in homes where guests currently have to walk through a bedroom to reach a bathroom.
Borrowing even 20 inches of hallway width across a short run can be enough. The hallway still functions perfectly well, and the home gains a bathroom.
5. Stealing Square Footage From an Adjacent Bedroom
This one makes people nervous, but it’s often the smartest move in the house. A fourth bedroom that measures 14 by 12 feet can give up three or four feet along one wall and still function as a comfortable bedroom — while enabling a full en suite bath for the room next door.
In many Chicagoland neighborhoods, converting a bedroom from “generic” to “en suite primary” adds more value than keeping the extra floor space. Appraisers and buyers both reward bathroom count.
Our approach: We model the “after” dimensions carefully and walk you through them in person before any wall moves. You should be able to picture exactly how the bedroom will feel.
6. The Attic Conversion With a Tucked-In Bath
Chicago’s story-and-a-half bungalows and Cape Cods often have attic space that’s partially finished or begging to be. The challenge is almost always the sloped ceiling — but a bathroom is actually the ideal use for low-headroom areas.
A toilet, a vanity, or a soaking tub can all live comfortably under a slope where a bed or dresser can’t. Placing the shower under the ridge where headroom is tallest, and tucking lower fixtures beneath the eaves, makes efficient use of every inch.
Don’t skip this step: Attic bathrooms require careful attention to floor framing, plumbing vent routing through the roof, and insulation detailing. Done right, it’s one of the most transformative upgrades a bungalow can get.
7. Mudroom and Back Entry Reconfiguration
Rear entries, enclosed back porches, and mudrooms often hold more square footage than they need — or they’re being used inefficiently with oversized built-ins. Reworking this zone can produce a half bath that’s genuinely useful for a family with kids, pets, or a backyard that sees heavy use.
Bonus: these spaces are frequently near existing plumbing runs from the kitchen, and they already have access to exterior walls for venting.
How to Tell If Your Home Has Hidden Bathroom Space
Before you assume you’re out of room, consider these questions:
Where is your existing plumbing? Stacking a new bathroom above, below, or directly beside existing plumbing dramatically reduces cost and complexity. Walk your home and note where kitchens, baths, and laundry hookups sit in relation to each other.
What’s the smallest footprint you actually need? A powder room can work in 11 to 18 square feet. A three-quarter bath with a shower typically needs 30 to 40. A full bath with a tub generally wants 40 or more. Many homeowners are surprised how little space a well-planned half bath requires.
Which rooms are underperforming? Formal dining rooms, oversized closets, double-wide hallways, and seldom-used dens are all candidates. If a space isn’t earning its square footage, it’s a candidate for conversion.
Can you go up or down? Attics and basements represent the largest pools of untapped space in most Chicagoland homes.
What Chicagoland Homeowners Should Know About Permits
Adding a bathroom almost always requires a permit, and requirements vary significantly across our service area. The City of Chicago has its own code and inspection process, while suburbs like Evanston, Oak Park, Wilmette, Naperville, and Elmhurst each maintain their own building departments and timelines.
Plumbing work in Illinois must be performed by a licensed plumber, and new bathrooms trigger requirements around ventilation, GFCI protection, egress considerations in basements, and fixture clearances.
Century City Baths handles permitting as part of our process. We know the local departments, we know what inspectors look for, and we build realistic timelines around municipal review periods rather than promising dates we can’t control.
What It Typically Costs
Costs vary widely based on scope, but here’s a general framework for the Chicagoland market:
- Powder room in existing space near plumbing: This is the most affordable path, since demolition is minimal and plumbing runs are short.
- Full bathroom carved from existing interior space: Moderate cost, driven largely by how far plumbing has to travel and whether structural work is needed.
- Basement bathroom requiring an ejector system: Higher cost due to pump installation, concrete cutting, and moisture detailing.
- Attic bathroom: Variable, depending on framing, access, and whether the attic is already conditioned space.
The biggest cost drivers are almost always distance from existing plumbing, structural modifications, and fixture selections. We provide detailed, itemized estimates so you understand exactly where your budget is going.
Why Finding Space Beats Building New
An addition means excavation or foundation work, new exterior walls, roofing, siding, windows, and often a zoning review. Converting interior space skips nearly all of it.
You keep your yard. You keep your setbacks. You typically keep your project timeline measured in weeks rather than months. And in many cases, you add the same functional value — and the same resale appeal — at a fraction of the cost and disruption.
Let’s Find Your Hidden Bathroom
Every home has a floor plan with assumptions baked into it, and those assumptions were made by someone who didn’t know how you live. Century City Baths specializes in looking past them.
We serve homeowners throughout Chicago and the surrounding suburbs, and we’d be glad to walk your home with you, identify the realistic options, and give you honest guidance on what’s possible — including when the answer is “this one isn’t worth it.”
Ready to see what’s hiding in your floor plan? Contact Century City Baths to schedule a consultation. Bring your questions, your frustrations with your current layout, and your wish list. We’ll bring the experience to turn them into a plan.
