Hobless shower

A hobless (or level-entry) shower is a shower with no step or hob at the threshold. The bathroom floor flows continuously into the shower zone, with the entire floor area falling to a floor waste inside the shower. Hobless showers are mandatory under NCC Volume Two Part H8 (Livable Housing, Silver Level) for new Class 1a dwellings from May 2023, and they are the default in any AS 1428.1-compliant accessible bathroom.

Why builders need to know:

• Mandatory NCC requirement for new Class 1a from May 2023 (with state-by-state adoption , see NCC Livable Housing Silver for the adoption status).
• Coordination starts at frame: the set-down in the floor structure (typically 35-50 mm) must be designed in at the slab or floor-joist stage. Retrofitting at tile stage is expensive.
• Multiple trades affected: chippy (floor frame set-down), plumber (floor waste position and depth), waterproofer (fall design, membrane lap), tiler (screed-to-fall, tile bedding).

Construction approach (slab-on-ground):

1. Slab set-down in the shower zone: 35-50 mm below the surrounding bathroom floor level.
2. Floor waste pre-cast at the deepest point of the set-down, with falls of 1:80 (1.25%) minimum from all edges to the waste per AS 3740.
3. Bathroom floor finished height must be ≥ 5 mm above the perimeter of the shower set-down at all points, OR the entire bathroom is treated as wet area with continuous fall toward the floor waste.
4. Waterproof membrane: full-bay membrane to AS 3740, with lap onto walls and step-down zone. Hobless construction is higher-risk for water escape than hobbed, so membrane quality is critical.
5. Screed-to-fall: tilers run mortar bed at 1:80+ to the floor waste.
6. Tile: laid on the screed, finished with a flush transition at the shower-entry line.

Construction approach (timber floor):

1. Joist deepening or bearer adjustment in the shower zone to create a 50 mm set-down at the floor sheeting level.
2. Floor sheeting (compressed sheet flooring or fibre cement) cut to the set-down profile.
3. Floor waste routed through the joist space.
4. Falls and waterproofing as for slab.

Common builder errors:

• Forgetting the set-down at slab stage: discovered at tile stage. Fix is to grind the slab (expensive, risk of damaging slab), build up bathroom floor with screed (raises threshold; may need door re-trim), or accept a hobbed design (and rebrief the client and certifier).
• Floor waste set too high: tiles never fall to the waste; water pools.
• Bathroom floor not falling to the shower waste: the bathroom develops its own water-pooling zones outside the shower.
• Door threshold at floor level without a transition strip or seal: water can escape the bathroom.
• Membrane lap inadequate: water tracks under the membrane at the set-down step.

Cost band (residential, 2026 AUD ex-GST):

Item	Hobbed shower (baseline)	Hobless shower
Slab set-down	nil	$200-$500
Waterproofing	$600-$1,200	$800-$1,800
Tiling labour	$80-$120/m²	$90-$140/m² (more fall work)
Floor waste relocation	nil	nil (just position planning)
Total premium	(baseline)	~$500-$1,500 if designed-in; $3,000-$8,000+ if retrofitted

For builders:

1. Design hobless from concept on any Class 1a build subject to NCC H8 (and on any future-proof brief from the client). Don’t try to retrofit.
2. Brief every wet-area trade at the start: chippy on set-down, plumber on waste position, waterproofer on membrane, tiler on fall.
3. Confirm the threshold detail at design lock-in: is the transition flush, with a seal, or with a slot drain at the door?
4. Spec a 100 x 100 floor waste minimum (some designs use a linear slot drain at the rear or one side of the shower zone , cleaner aesthetic, requires careful planning).

Also known as: level-entry shower, step-free shower, level-access shower, wheelchair-accessible shower.

Category: Wet area / accessibility / NCC compliance.

Related

• NCC Livable Housing Silver
• AS 1428
• AS 3740

See also

• Wet area waterproofing

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Last updated: 2026-05-15. Verified: 2026-05-15.