Stair Layout Sheet
Work it out before cutting anything, and check the total run against the space you actually have — that is the number that most often kills a design.
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The staircase
- Location
- Date
- Total rise (finished to finished)
- Max riser (LOCAL CODE)
- RISERS
- Actual riser height
- TREADS
- Tread depth
- TOTAL RUN
- Headroom available
Check every riser once built — variation is the hazard
| Riser # | Measured height | Difference from target | OK? |
|---|---|---|---|
The arithmetic
- Risers
- total rise / max riser, rounded UP
- Actual riser
- total rise / number of risers
- Treads
- risers MINUS 1
- Total run
- treads x tread depth
- Comfort rule
- riser + tread ≈ 17-18 in
- Comfort rule
- 2 x riser + tread ≈ 24-25 in
- ⚠ Total rise means
- FINISHED floor to FINISHED floor
- ⚠ All limits are
- LOCAL CODE — the defaults are not permission
Before cutting a stringer
- Local code checked: max riser, min tread, headroom, handrails, landings
- Total rise measured to FINISHED floor at both ends
- Floor finishes decided — they change the top and bottom risers
- Total run checked against the actual space, plus clear space at each end
- Headroom checked along the whole flight, not just at the bottom
- Riser height divided evenly — never let the last one take the remainder
- Tread count confirmed as risers minus one
- Handrail height and graspability planned
- One stringer cut and TEST-FITTED before cutting the rest
The run is what kills the design
Almost everyone works out the rise first and is fine. The total run — nearly eleven feet on the default figures, plus clear space top and bottom — is what turns out not to fit. Work it out before the layout is drawn rather than after, because the only ways to shorten it are a steeper stair, a winder or a landing, and all three are decisions rather than adjustments.
One different riser is the whole hazard
People climb by rhythm. After two steps your body predicts the next tread and commits your weight before your eyes confirm anything, so a riser out by even a fraction breaks that prediction at the worst possible moment. This is why codes limit variation across a flight so tightly, and why the actual riser height is shown here to four decimal places.
Stairs are code work
This sheet does arithmetic. Every limit in it — riser height, tread depth, headroom, handrails, landings — is set by your local building code, varies by jurisdiction, and differs between dwellings, commercial buildings and loft conversions. The defaults are common residential figures, not permission to build.