What Is the Minimum Shower Size in Florida? Area, Narrowest Side, Door Opening — and Remodels

What is the minimum shower size in Florida?

At least 900 square inches of floor inside the finished walls, and no side shorter than 30 inches. The Florida Building Code, Residential says shower compartments shall have not less than 900 square inches of interior cross-sectional area and shall be not less than 30 inches in minimum dimension [1]; the Florida Building Code, Plumbing sets the same two numbers [2].

Both rules have to be met at once. A 30 × 30 inch shower has exactly 900 square inches and no side under 30, so it is the smallest square shower that passes. A 32 × 32 shower has 1,024 square inches and passes with room to spare. A 28 × 36 shower has 1,008 square inches — more than 900 — but fails, because one side is under 30 inches.

The code sets a minimum, not a comfortable size. Where the toilet and vanity go around the shower is a separate set of rules; our article on how much space a toilet needs covers the 15-, 30- and 21-inch clearances.

Does a shower have to fit a 30-inch circle?

Not in the Florida text. The 2023 Florida Building Code, Residential and Plumbing both write the rule as a 30-inch minimum dimension, and neither shower section uses the word circle [1][2]. If you read about a 30-inch circle, that wording comes from somewhere other than the Florida sections cited here.

In a plain rectangular shower the two come to the same thing: if no side is under 30 inches, a 30-inch circle fits inside. The difference shows in odd shapes — a neo-angle corner or a shower with a bench along one wall — where the narrowest point is what has to be checked against 30 inches.

How is shower size measured — to the studs or to the tile?

To the finished surface. Both codes measure the area and the minimum dimension from the finished interior of the compartment, at a height equal to the top of the threshold [1][2]. Fixture valves, shower heads, soap dishes and grab bars or rails are not counted against it [1][2].

So the framing has to be bigger than the number. Trade practice is to add the thickness of the wall board, the waterproofing and the tile on each side before the studs go up; a framed opening of exactly 30 inches will finish under 30.

The same sections also say the finished, water-resistant wall continues to at least 70 inches above the shower drain outlet [1][2]. The drawing shows three floors at the same scale: one that meets the minimum, one that uses the narrow-shower exception, and one that fails.

Can a shower be narrower than 30 inches?

Yes, down to 25 inches — but only if it is long enough to make up the area. Both codes have the same exception: a shower with a minimum dimension of not less than 25 inches is allowed when it has at least 1,300 square inches of cross-sectional area [1][2].

That means a 25-inch-wide shower has to be at least 52 inches long (25 × 52 = 1,300). A 26 × 40 shower has 1,040 square inches: more than 900, but its narrow side is under 30 and its area is under 1,300, so it meets neither the main rule nor the exception. Nothing narrower than 25 inches is allowed under either.

A fold-down seat does not shrink the shower in the code’s eyes as long as the 900 square inches is still there with the seat folded up; that exception is written in the Residential code [1].

How wide does a shower door or opening have to be?

At least 22 inches clear. Both codes require the shower’s access and egress opening to have a clear and unobstructed finished width of not less than 22 inches [1][2]. That is the clear width you can walk through, not the size of the glass panel.

The Residential code adds that hinged shower doors shall open outward [1]. A door that swings into the bathroom needs room to swing, which is one more reason to plan the shower together with the toilet and vanity rather than after them.

Which code applies — a house or a condo?

A house or townhouse goes by the Residential code; most other buildings by the Plumbing code. The Florida Building Code, Residential covers detached one- and two-family dwellings and townhouses not more than three stories above grade plane with a separate means of egress [3], and the Florida Building Code, Building sends those same dwellings to the Residential code [4]. Its shower rule is §P2708 [1].

Buildings outside that scope — a condominium or apartment building, for example — are built to the Florida Building Code, Building, whose plumbing is the Florida Building Code, Plumbing, where showers are §421 [2][4]. For the size of a shower it makes no difference: 900 square inches, 30 inches, the 25-inch exception with 1,300 square inches, and a 22-inch opening appear in both [1][2]. The fold-down seat exception and the outward-opening hinged door are written in the Residential section [1].

Does an old shower have to be brought up to the minimum size in a remodel?

Not just because it exists, but new work is held to the new-work rules. The shower sections themselves have no exception for existing or remodelled showers; their only exceptions are the 25-inch one and, in the Residential code, the fold-down seat [1][2].

The Residential code’s general rule is that additions, alterations, renovations or repairs to a plumbing system shall conform to what is required for a new system, without requiring the existing system to comply with the code [5]. It also allows minor alterations and repairs in the same manner and arrangement as the existing system, provided they are not hazardous and are approved [5]. And it says existing buildings undergoing repair, alteration, additions or change of occupancy are to follow the Florida Building Code, Existing Building [3].

Our reading: keeping an old, small shower where it is when you replace the tile or the valve is the existing arrangement; building a new shower, or moving and re-framing one, is new work and should be laid out to 900 square inches and 30 inches. Where the line falls on a particular job is the building official’s call, not ours.

What about the curb and the shower pan liner?

They have their own rules, and we cover them in a separate article. On a tiled shower built on site, the liner under the floor is what keeps water in the shower; its turn-up above the finished threshold, its slope and its flood test are explained in what is under your shower floor, and what a failing one looks like in signs of a leaking shower pan.

The photograph shows a 40 mil PVC shower pan liner installed across a wide shower base in St. Petersburg, before the mortar bed and tile.

How big is an accessible (ADA) shower?

Bigger than the code minimum. The 2010 ADA Standards for Accessible Design set a transfer-type shower at 36 × 36 inches clear inside with a 36-inch-wide entry, a standard roll-in shower at 30 inches wide by 60 inches deep with a 60-inch-wide entry, and an alternate roll-in shower at 36 × 60 inches with a 36-inch entry at one end of the long side [6]. A roll-in shower’s threshold is half an inch high at most [6].

Those Standards are written for state and local government facilities and for public accommodations and commercial facilities [6]. In a private house they are a reference you can choose to build to — for example, a curbless shower for someone who uses a wheelchair.

What this means in Clearwater and across Tampa Bay

The Florida Building Code is the state’s code, so the 900-square-inch and 30-inch minimums are the same in Clearwater, St. Petersburg and Tampa [1][2]. The sections on this page are from the 8th edition (2023).

The photograph at the top of this page is ours, in Clearwater: a 40 mil PVC shower pan liner in a framed alcove with PEX supply lines above. If you are planning a new shower or moving one, call 727-470-7126 with the measurements of the room and we will tell you whether the shower you want fits the code before the wall is framed.

FAQ

Sources

We review and cite. We do not reproduce a paper or a manual — follow the links for the originals.

1. [1]2023 Florida Building Code, Residential, 8th Edition — Chapter 27, Plumbing Fixtures (§P2708.1 Showers, §P2708.1.1 Access) — International Code Council / Florida Building Commission · 2023Law / code · §P2708.1: not less than 900 sq in of interior cross-sectional area; not less than 30 in in minimum dimension, measured from the finished interior dimension at a height equal to the top of the threshold, exclusive of fixture valves, shower heads, soap dishes and safety grab bars or rails; finished wall continued to not less than 70 in above the shower drain outlet; hinged shower doors shall open outward; exception 1: fold-down seats permitted if the 900 sq in is maintained with the seat folded up; exception 2: not less than 25 in minimum dimension with not less than 1,300 sq in of cross-sectional area; the word “circle” does not appear; no exception for existing or remodelled showers; §P2708.1.1: access and egress opening clear and unobstructed finished width not less than 22 in; read on up.codes 2026-11-09 because codes.iccsafe.org returns 403 to our fetcher
2. [2]2023 Florida Building Code, Plumbing, 8th Edition — Chapter 4, §421.4 Shower compartments and §421.4.2 Access — International Code Council / Florida Building Commission · 2023Law / code · §421.4: not less than 900 sq in interior cross-sectional area; not less than 30 in in least dimension measured from the finished interior dimension, exclusive of fixture valves, showerheads, soap dishes and safety grab bars or rails; measured at a height equal to the top of the threshold and continued to not less than 70 in above the shower drain outlet; exception: not less than 25 in minimum dimension with not less than 1,300 sq in; §421.4.2: clear and unobstructed finished width not less than 22 in; the word “circle” does not appear; showers are §421 in this edition, not §417; read on up.codes 2026-11-09 because codes.iccsafe.org returns 403 to our fetcher
3. [3]2023 Florida Building Code, Residential, 8th Edition — Chapter 1, §R101.2 Scope — International Code Council / Florida Building Commission · 2023Law / code · applies to detached one- and two-family dwellings and townhouses not more than three stories above grade plane with a separate means of egress; exception 3: existing buildings undergoing repair, alteration, additions or change of occupancy follow the Florida Building Code, Existing Building; read on up.codes 2026-11-09 because codes.iccsafe.org returns 403 to our fetcher
4. [4]2023 Florida Building Code, Building, 8th Edition — Chapter 1, §101.2 Scope — Florida Building Commission (read on UpCodes) · 2023Law / code · applies to the construction, alteration, relocation, enlargement, replacement, repair of buildings; exception 1: detached one- and two-family dwellings and townhouses not more than three stories above grade plane with a separate means of egress shall comply with the Florida Building Code, Residential; read 2026-11-09
5. [5]2023 Florida Building Code, Residential, 8th Edition — Chapter 25, §P2502.2 Additions, Alterations or Repairs — International Code Council / Florida Building Commission · 2023Law / code · additions, alterations, renovations or repairs conform to that required for a new plumbing system without requiring the existing system to comply; shall not make an existing system unsafe, insanitary or overloaded; minor additions, alterations, renovations and repairs permitted in the same manner and arrangement as the existing system, provided not hazardous and approved; read on up.codes 2026-11-09 because codes.iccsafe.org returns 403 to our fetcher
6. [6]2010 ADA Standards for Accessible Design — §608 Shower Compartments — U.S. Department of Justice, ADA.gov · 2010Government or standards body · §608.2.1 transfer type: 36 x 36 in clear inside, 36 in wide minimum entry, clearance 36 x 48 in; §608.2.2 standard roll-in: 30 in wide x 60 in deep minimum, 60 in wide minimum entry; §608.2.3 alternate roll-in: 36 x 60 in, 36 in entry at one end of the long side; §608.7: roll-in thresholds 1/2 in high maximum; the standards apply to state and local government facilities (title II) and public accommodations and commercial facilities (title III); read 2026-11-09