The detail that costs you — #01: Why your stairs might fail final inspection

A staircase can be built well and still fail inspection. Here's the 30-second check.

For a private stair in a home, the code sets three numbers. Each riser: between 115 and 190 millimetres.

Each going — the flat part you step on: between 240 and 355.

And the relationship between them: two times the riser plus the going must land between 550 and 700. Around 620 is the comfortable sweet spot.

Two more that catch people: risers in a flight have to be near-equal — no more than a few millimetres of variation. And past 18 risers, you need a landing.

Where it goes wrong on site: the top or bottom riser ends up different after the floor finish goes down. Tiles, overlay, screed — they change the first riser height, and that's the one certifiers measure.

That's the check. You can do it off this video. When the answer's buried in your own plans and specs, AskThePlans finds it and cites the drawing and page. You keep the judgement — it does the finding.

Prefer watching? The full video is embedded above.