The rise and run of a stairway makes it comfortable (or not).
Running the numbers shows a run of 280mm and a rise of 180mm is a good starting point.
The minimum head height is 2000mm. See below (from https://www.tkstairs.com). Assume some tolerance, so use 2100mm. Add in 200mm for joists, and we need to drop 2300mm before we can ‘cover’ the stair. This is 13 rises or 3600mm in run.
Where steep stairs are required:
- NCC maximum rise is 190
- 200 rise / 250 run seems reasonable
- 220 rise / 240 run seems a reasonable upper limit.