Sanitary Fixture Counts: Getting the Numbers Right
What You Need to Know
Every building needs a set number of toilets, urinals, and washbasins. The NCC sets those numbers based on building class, how many people use the space, and what they use it for. Get the count wrong, and the certifier will send you back to the drawing board. Get the accessible provisions wrong, and you fail the Premises Standards too.
The rules sit in NCC 2025 Part F4 (Tables F4D4a through F4D4l). Before NCC 2025, these lived in Part F2. If you are still using F2 references for fixture counts, you are reading the wrong section.
The Rules
- Fixture counts for employees in Class 5 offices, Class 6 shops, and Class 9 buildings come from Table F4D4a (NCC 2025, F4D4)
- Class 7 and 8 buildings (car parks, factories, warehouses) use Table F4D4b (NCC 2025, F4D4)
- Restaurants and cafes need patron toilets on top of staff toilets, per Table F4D4d (NCC 2025, F4D4)
- Work out occupant numbers using Table D2D18, which divides floor area by a density factor for each use type (NCC 2025, D2D18)
- Assume a 50/50 male-to-female split unless the building is predominantly single-sex (NCC 2025, F4D3)
- Provide at least 1 accessible unisex toilet on every storey that has sanitary facilities. If a storey has more than one bank, put accessible compartments at no fewer than 50% of banks (NCC 2025, F4D6)
- Provide at least 1 ambulant cubicle per sex at every bank of standard toilets (NCC 2025, F4D5)
- Accessible unisex compartments count toward both the male and female totals (NCC 2025, F4D3(3))
What This Means in Practice
Take a 3-storey Class 5 office building. Each floor has 1,200 m² of net lettable area. Table D2D18 assigns a density factor for each use type. For a general office, this is commonly around 15 m² per person, giving about 80 occupants per floor (40 male, 40 female). Check D2D18 for the exact figure that matches your use description.
For males on each floor, Table F4D4a requires 2 closet pans (1 for the first 20, plus 1 for the next 20), 1 urinal (1 for 11–25 persons, none extra until you pass 50), and at least 1 washbasin. For females, you need 3 closet pans (1 for the first 15, plus 1 for each additional 15).
Now add the accessible and ambulant provisions. Each floor needs 1 accessible unisex compartment (which counts toward both sexes) and 1 ambulant cubicle in the male block and 1 in the female block. The accessible toilet takes roughly 2,300 mm × 1,900 mm of clear floor space (AS 1428.1, Cl 12). Each ambulant cubicle needs a width of 900 to 920 mm and grab rails on both sides (AS 1428.1, Cl 16).
Miss the ambulant cubicles at design stage and you will lose standard cubicle space later. Miss the accessible compartment on one floor and the whole building fails certification.
Key Design Decisions
Count Occupants Before You Count Fixtures
The fixture numbers flow from the occupant count, not from the number of desks or tenancies. Use Table D2D18 to work out the occupant density for each use type. A Class 5 office (commonly around 15 m² per person) gives a very different count to a Class 6 restaurant with its much higher density. Lock in the occupant numbers at concept design. If they change, the fixture count changes too.
Plan Accessible and Ambulant Facilities Early
Accessible unisex toilets need a clear floor area of at least 2,300 mm × 1,900 mm (AS 1428.1). They are much larger than a standard cubicle. If you do not reserve this space at concept stage, it will not fit later without re-planning the core.
Ambulant cubicles at 900–920 mm wide with grab rails are only slightly wider than standard cubicles. But they need an outward-opening or sliding door with a 700 mm clear opening (AS 1428.1, Cl 16). Plan for this door swing in the corridor or circulation space.
Check Both Employee and Patron Tables
In Class 6 buildings (shops, restaurants), staff and patrons need separate counts from separate tables. Staff facilities come from Table F4D4a. Patron facilities come from Table F4D4c (retail) or F4D4d (food and drink). The patron numbers are often much higher because of the occupant density.
Consider All-Gender and Unisex Options
The NCC allows unisex facilities in certain situations under F4D4(3) and (4). Some projects, like co-working spaces or small tenancies, benefit from unisex toilets that serve everyone. Each unisex cubicle counts toward both male and female totals, so the total number of fixtures can drop. But check with your certifier: not all consent authorities accept this approach for every building class.
Who Needs to Know What
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References
- National Construction Code 2022, Volume One, Part F4 — Sanitary and other facilities
- National Construction Code 2022, Volume One, Tables F4D4a–F4D4l — Fixture count tables by building class
- National Construction Code 2022, Volume One, D2D18 — Determination of number of persons
- AS 1428.1:2021, Design for access and mobility — General requirements for access — New building work
- AS 1428.1:2021, Clause 16 - Sanitary facilities for ambulant persons with disability
- AS 1428.1:2021, Clause 12 - Sanitary facilities (accessible compartments)
- ABCB Sanitary Facilities Calculator (NCC 2025 Volume One)