How to Draw Stairs in ArchiMaster 3D: Tread & Riser Settings

To draw a custom staircase in ArchiMaster 3D, open the Staircase Generator from the Build menu, choose a stair type, enter the overall rise and run, then set tread depth and riser height to code. The tool recalculates the flight automatically and gives you landing, stringer, and nosing controls in one panel. This is faster than modeling steps as individual boxes, and it keeps every riser, tread, and landing tied to the same dimension set. The same tool is available across the ArchiMaster 3D product line, so the workflow below applies whether you are planning a full remodel or a single deck stair.

• Open the Staircase Generator from the Build panel. Selecting the stair type first matters, because switching from Straight to U-Shaped resets landing and stringer parameters.
• Set residential riser height no higher than 7.75 in (196 mm) and tread depth no less than 10 in (254 mm) to meet IRC 2021 rules. Check local amendments.
• Use the Auto-Adjust toggle before changing total rise. It keeps every riser identical and prevents uneven steps, the most common code rejection.
• Check Stringer Offset and Nosing Projection before exporting. Misaligned handrails in CAD usually trace back to these two fields.

“A stair that passes inspection and walks well starts with two numbers: a riser no higher than 7.75 inches and a tread no shorter than 10 inches.”, ArchiMaster 3D Journal

Open the Staircase Generator and Choose a Stair Type

In ArchiMaster 3D, the fastest path is not to draw individual treads. Select Build, then Staircase, then Staircase Generator. The generator opens a settings panel with a live 3D preview on the right. The first field to set is Type. Straight stairs are the default, but L-Shaped, U-Shaped, and Spiral types are available from the same control. Changing the type after you have entered dimensions resets most landing and stringer logic, so choose the type before entering numbers. If you need a deck stair or a short exterior run, the same tool works after selecting the exterior wall or deck edge. For a full tour of the toolset, see the ArchiMaster 3D features overview.

• Open a plan and set the floor height between levels, including finish floor thickness.
• Click Build > Staircase > Staircase Generator.
• Set Type to Straight, L-Shaped, U-Shaped, or Spiral.
• Pick the start point by clicking the floor or deck edge.
• Enter Total Rise as the finished floor to finished floor dimension.
• Set Width in the Dimensions group, usually 36 in for residential and 42 in for comfortable two-way traffic.
• Leave the advanced fields for the next step, then click Generate to see the base stair.

Set Tread Depth and Riser Height Correctly

The two numbers that decide whether a stair walks comfortably and passes inspection are tread depth and riser height. In the generator, these sit under the Treads and Risers group. Tread depth is the horizontal distance from the face of one riser to the face of the next, not including the nosing. Riser height is the vertical distance between two consecutive tread tops. ArchiMaster 3D opens with a common starting set, often around a 10-inch tread and a 7-inch riser, but these are only starting values. The correct pair for your project depends on the total rise and the available run. A shallower riser and deeper tread make the stair easier to climb, at the cost of more floor space.

Code-Compliant Residential Numbers

For a straight residential stair under the 2021 International Residential Code, the maximum riser height is 7.75 inches and the minimum tread depth is 10 inches, measured nose to nose. Nosing projection must be between 0.75 inch and 1.25 inches. Spiral and winder stairs have different rules: winder treads must be at least 6 inches at the narrow edge and 10 inches at the 12-inch walk line. In the ArchiMaster 3D settings panel, set the riser value in the Riser Height field and the run in the Tread Depth field. Then open the Nosing group and set the projection. If a local code requires a 7.5-inch maximum riser, use that number instead of the IRC limit.

Use Auto-Adjust to Keep Risers Equal

The most common stair mistake is a first or last riser that is shorter than the rest. That happens when the total rise does not divide evenly by the chosen riser height. ArchiMaster 3D has an Auto-Adjust toggle in the Treads and Risers group. When it is on, the software recalculates the riser height across the full flight so every step is identical. Turn it on after entering the total rise, then lock the result. If you need a specific riser height, adjust the total rise or the number of treads instead of editing one riser manually. Manual overrides create the exact uneven edge that inspectors flag.

Add Landings, Stringers, and Handrails

After the flight geometry is set, the generator adds landings and structural members from the same control. For an L-Shaped or U-Shaped stair, set the Landing Length and Landing Width in the Landing group. The landing depth should match the stair width, so a 36-inch-wide stair gets a 36-inch landing. For a straight stair, you can still add a mid-flight landing by inserting a break point in the flight path. Stringers are controlled under the Stringers group. The Stringer Offset field moves the structural cut line from the edge of the tread, and the Stringer Count sets one, two, or three supports depending on stair width. Handrail and guardrail appear as 3D objects after you check the Railings box.

• Set landing depth equal to stair width; a 36-inch stair gets a 36-inch landing.
• Use three stringers for stairs wider than 36 inches to reduce bounce under load.
• Keep nosing projection between 0.75 and 1.25 inches so the tread edge is safe but not a trip hazard.
• Check the Railings box before generating the 3D view; handrails update only when the box is on.

Check Headroom, Clearances, and Export Notes

Before you finish the stair, check headroom and clearance in the 3D view. The IRC requires 6 feet 8 inches of headroom measured vertically from the sloped plane of the stair nosings to the ceiling or landing above. In ArchiMaster 3D, rotate the camera to a side elevation and use the dimension tool to confirm the clearance. Stair width measured between handrails must be at least 31.5 inches for exterior egress stairs if the total rise exceeds 30 inches. When the model looks correct, export the plan view to DWG or PDF for permit review. The same generator data feeds material and cut lists, so your builder gets matching tread, riser, and stringer counts. If you are still comparing software, download the free trial and build this exact stair in your own plan. For regional renovation cost context, see the 2026 home design statistics roundup.