3.1 Minimum Fixture Counts, Separate Facilities, and Toilet Room Location

The eight-item content area

Fixtures and Equipment supplies 8 scored items on the Journeyworker exam. Most of them come from four places: Table 403.1 counts, the 405.3.1 clearances, the fixture-specific outlet sizes in Sections 419 through 425, and the temperature-limiting requirements of Section 412. This section covers the first of those.

How the count is calculated — IPC 403.1.1

Getting the arithmetic right matters more than memorizing the table, because the table is open in front of you on exam day.

1. Determine the occupant load from the International Building Code. The IPC does not set occupant load.
2. Divide the total occupant load in half to get the load of each sex.
3. Apply the ratio for each fixture type from Table 403.1 to the load of each sex.
4. Round every fractional result up to the next whole number.
5. For multiple occupancies, sum the fractional numbers for each occupancy first, then round up.

Three exceptions to the divide-in-half rule:

• Approved statistical data showing a distribution other than 50/50.
• Multiple-user facilities designed to serve all genders, where the count is based on 100 percent of the total occupant load, each fixture type complies with ICC A117.1, and each urinal provided is located in a stall.
• Where single-user water closet and bathing rooms are provided under 403.1.2.

IPC 403.1.2 counts single-user toilet and bathing rooms — including family or assisted-use rooms — toward the total required fixtures, and requires them to be identified as available to all persons regardless of sex. IPC 403.1.3 requires lavatories to be distributed proportionately to the required water closets where two or more toilet rooms serve each sex.

Worked count: a business occupancy

An office building has an occupant load of 180.

• Load per sex: 180 / 2 = 90 each.
• Water closets, business: 1 per 25 for the first 50, then 1 per 50 for the remainder.
  • First 50 -> 50 / 25 = 2. Remainder 40 -> 40 / 50 = 0.8. Total 2.8 -> round up to 3 per sex.
• Lavatories, business: 1 per 40 for the first 80, then 1 per 80 for the remainder.
  • First 80 -> 80 / 40 = 2. Remainder 10 -> 10 / 80 = 0.125. Total 2.125 -> round up to 3 per sex.
• Drinking fountains: 1 per 100 -> 180 / 100 = 1.8 -> 2 total.
• Service sink: 1 (not required at an occupant load of 15 or fewer, per footnote e).

Result: 3 water closets and 3 lavatories per sex, 2 drinking fountains, 1 service sink.

Substituting urinals: business is not assembly or educational, so urinals may replace not more than 50 percent of the male water closets (424.2). Three male water closets means 1 may be replaced by a urinal, since 50 percent of 3 is 1.5 and you cannot exceed 50 percent.

Reading Table 403.1

The table is organized by the eight IBC occupancy groups. Ratios you should recognize on sight:

Footnotes worth knowing:

• a. One fixture is the minimum required for the stated number of persons or any fraction of that number.
• b. Employee toilet facilities must be separate from facilities for inmates or care recipients.
• d. The occupant load for seasonal outdoor seating and entertainment areas counts toward the minimum.
• e. Business and mercantile with an occupant load of 15 or fewer do not require a service sink.

Apartment houses additionally require 1 kitchen sink per dwelling unit and 1 automatic clothes washer connection per 20 dwelling units; one- and two-family dwellings require 1 kitchen sink and 1 clothes washer connection per dwelling unit.

Separate facilities and the six exceptions

IPC 403.2: where plumbing fixtures are required, separate facilities shall be provided for each sex — unless one of six exceptions applies:

1. Dwelling units and sleeping units.
2. Structures or tenant spaces with a total occupant load of 15 or fewer, employees and customers combined.
3. Mercantile occupancies with a maximum occupant load of 100 or fewer.
4. Business occupancies with a maximum occupant load of 25 or fewer.
5. Where single-user toilet rooms are provided under 403.1.2.
6. Where rooms with both water closets and lavatories are designed for both sexes with water closet privacy per 405.3.4; urinals must be visually separated or each in a stall.

The three numeric thresholds — 15 total, 100 mercantile, 25 business — are a favorite exam target because they are easy to transpose.

Where the facilities must be

IPC 403.4 requires signs designating the sex, readily visible near the entrance, with accessible-facility signs per IBC Section 1111, and 403.4.1 requires directional signage readable from the main entrance of the building or tenant space.

Accessible fixtures

IPC 404.1 sends the question of where accessible facilities are required to Chapter 11 of the International Building Code, and 404.2 sends how they are installed to ICC A117.1. The IPC itself does not contain accessible stall dimensions. Note that IPC 405.3.1 contains a single accessibility-flavored exception of its own: an accessible children's water closet may be set as close as 12 inches from its center to the required partition or wall on one side.

Group wash fixtures and urinal substitution

• IPC 419.1: for determining the number of lavatories required by Table 403.1, every 20 inches of rim space on a group wash fixture counts as one lavatory. A 100-inch circular wash fountain therefore counts as five lavatories.
• IPC 424.2: urinals may substitute for not more than 67 percent of required water closets in assembly and educational occupancies, and not more than 50 percent in all other occupancies.

Colorado field note (not exam-scored): Board Rule 1.2(E)(1)(r) adds a sentence to 403.1 requiring the lavatory-to-water-closet-or-urinal ratios in Table 403.1 to be maintained in all restrooms, and Rule 1.2(E)(1)(s) requires new or remodeled state, county, city and municipal buildings (excluding K-12 schools) to provide an ADA-compliant single-user or multi-user non-gendered restroom under C.R.S. 9-5.7-103. Rule 1.2(E)(1)(t) excludes classroom toilet rooms and their lavatories from the Table 403.1 count.