4 x 5 Bathroom Layout Ideas: Small Space, Smart Design

A 4 x 5 bathroom (20 square feet) may seem extremely small, but with the right layout, it can still be functional, stylish, and surprisingly comfortable. Whether you’re remodeling a guest bath, adding a powder room, or designing for an ADU or mobile home, this compact size demands thoughtful space planning.

Key Design Considerations for a 4 x 5 Bathroom

Before you look at layout options, make sure you factor in these space-saving essentials:

1. Use Wall-Mounted Fixtures – Wall-hung sinks and toilets free up floor space and make cleaning easier.
2. Choose a Pocket Door – A standard swing door takes up to 9 sq ft of clearance—switching to a sliding pocket door frees up layout possibilities.
3. Go Vertical – Install shelving, towel bars, and even a mirrored cabinet above the sink or toilet.
4. Compact Fixtures Only – Use a 15–16" deep sink, a 24" vanity, and a 25–28" round toilet to maintain comfort.
5. Maximize Light – Use light tile, glass partitions, or even a skylight to make the space feel larger.

Layout Option 1: Linear Layout (Sink–Toilet–Shower in Line)

Best For: Minimalist, long narrow rooms

1. All fixtures arranged along one wall
2. Walk-in shower at the far end (with curtain or half glass panel)
3. Wall-mounted sink and toilet in line

Experience Insight: This layout works best in narrow bathrooms where visibility and lighting come from one end. Keeping all plumbing on one wall simplified installation in several urban remodels I've worked on.

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Layout Option 2: Corner Shower with Floating Sink

Best For: Guest baths or studio apartments

1. Corner shower with curved or neo-angle door
2. Floating sink centered on short wall
3. Compact toilet on opposite end

Experience Insight: The curved shower saved crucial inches in a recent ADU conversion. Clients appreciated the openness it gave to the floor while still feeling like a "real" bathroom.

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Layout Option 3: Shower Opposite Sink & Toilet

Best For: Balanced look and easier plumbing

1. Sink and toilet share one long wall
2. Shower stall (30" x 30") across from toilet with glass door
3. Great for symmetrical layouts

Experience Insight: I used this setup for a downtown loft bathroom where the owner wanted a symmetrical layout. Framing the shower with glass helped maintain balance without sacrificing usability.

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Layout Option 4: Wet Room Style

Best For: Ultra-compact or accessible bathrooms

1. Entire room is waterproofed
2. Toilet, sink, and shower all share open space
3. No separate shower enclosure needed

Experience Insight: In a tiny cabin project, this layout made the space feel twice as big. Just be sure the floor is perfectly sloped and drainage is carefully planned—it’s the biggest challenge but totally worth it.

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Urban Loft Powder Room

Interior designer Sarah Lin converted a 4 x 5 space in a San Francisco loft into a fully functional guest bath:

"We used a floating vanity, large mirror, and walk-in shower with a half-glass wall. It felt small, but not cramped—light and airflow were everything."

Features used:

1. 12" x 24" subway tile in vertical stack
2. Brushed brass fixtures for contrast
3. Wall-mounted toilet with recessed shelving above

FAQs

Q: Can you fit a full shower in a 4 x 5 bathroom?

A: Yes, but it needs to be a compact stall—ideally 30" x 30" with sliding or curved doors.

Q: Can this size bathroom be ADA compliant?

A: Not fully. Most ADA bathrooms require more clearance, but a 4 x 5 space can be made more accessible with no-threshold showers and support bars.

Q: Is a bathtub possible in 4 x 5?

A: Very unlikely—there’s rarely enough space for a standard 5-ft tub unless it’s a Japanese-style soak tub.