Our Bendigo design has the laundry door opening straight onto a four-riser external stair down to the yard. The building surveyor wants a landing at the door. When is a threshold landing required, and how big does it need to be?

The building surveyor is right. Four risers is more than 3 risers, so the laundry door needs a threshold landing, and it must be at least 750 mm long, extend across the full width of the doorway, and have a gradient not steeper than 1:50. [1]

The trigger has two limbs, and you only need to hit one. A landing must be provided where the sill of a threshold of a doorway opens onto a stairway or ramp that provides a change in floor level or floor to ground level greater than 3 risers or 570 mm. [1] Figure 11.2.5b puts it plainly: a maximum of 3 risers or 570 mm, landing not required; more than 3 risers or more than 570 mm, landing required. [1] Your stair has four risers, so the landing is triggered on the riser count alone, whatever the total drop works out to be.

How big it has to be. Once triggered, clause 11.2.5(1) sets the landing's size and fall: [1]

• Length: not less than 750 mm. Where the landing involves a change in direction, the length is measured 500 mm from the inside edge of the landing (Figure 11.2.5a).
• Gradient: not steeper than 1:50. The Standard's explanatory information notes this keeps the landing as level as possible while still allowing a slight fall for drainage, which matters on an external landing. [4]
• Width: it must extend across the full width of the doorway.

The 600 mm concession does not apply to a laundry. Clause 11.2.5(2) allows a shorter landing of not less than 600 mm, but only for a stairway serving only non-habitable rooms, such as attics, storerooms and the like, that are not used on a regular or daily basis. [1] A laundry is used routinely and this stair is the path to the yard, so plan on 750 mm.

Do not confuse the landing with the threshold rule. Clause 11.2.6 is a separate test: where the threshold of a doorway is more than 230 mm above the adjoining surface, it must incorporate steps with riser and going dimensions complying with 11.2.2. [2] So set the landing level so the step down from the door sill onto it is not more than 230 mm, or that drop becomes a step in its own right.

The landing edge needs slip resistance too. Where the edge of the landing leads to the flight below, it must have either a surface meeting the Table 11.2.4 slip-resistance classification for not less than 190 mm from the stair nosing, or a nosing strip meeting that table. [3] The table gives separate dry and wet values, so check which applies to an exposed landing.

Practical next step. Redraw the back door detail with a landing of at least 750 mm by the full door width, show its fall at 1:50 or flatter, dimension the sill to landing drop, and note the landing edge treatment. That answers the surveyor's request on paper.

Victorian edition note. NCC 2025 has been the sole operative edition in Victoria since 1 May 2026. A project may remain on NCC 2022 only where the relevant building surveyor certified substantial design progress before that date under s10(2) of the Building Act 1993. Either way the answer is the same: NCC 2022 carries identical landing and threshold wording and figures. [5]