Handrail height by code
Every major code measures handrail height vertically from the line through the tread nosings, not from the tread surface. The limits:
| Code | Height | When required |
|---|---|---|
| US IRC 2021 R311.7.8 / 2024 R320.2[1][2] | 34 to 38 in (864–965 mm) | one side of every flight with 4 or more risers |
| US IBC 1014.2[3] | 34 to 38 in | commercial stairs |
| England, Approved Doc K 1.34[4] | 900 to 1,000 mm | both sides where the stair is 1 m wide or more |
| Scotland 4.3.15[5] | 840 mm to 1.0 m | per the handbook |
| Canada NBC 9.8.7.4[6] | 865 to 1,070 mm | not on interior stairs of 2 risers or fewer, or exterior stairs of 3 or fewer |
| Australia NCC 11.3.5[7] | at least 865 mm (no maximum) | not where the stair rises less than 1 m |
Handrail vs guard height
A handrail is the rail you hold; a guard is the barrier that stops a fall. On a stair the same rail can do both if it meets both rules: under the IRC a guard on the open side of a stair must be at least 34 in high, and a combined guard and handrail must be 34 to 38 in[1]. At landings and decks the guard must be at least 36 in, which the deck railing height page covers.
Grip size, clearance and continuity
- Grip: a round rail 1-1/4 to 2 in across; a non-round rail with a 4 to 6-1/4 in perimeter and at most 2-1/4 in cross-section (Type I)[1][2].
- Clearance: at least 1-1/2 in between the rail and the wall.
- Projection: at most 4-1/2 in into the stair width on each side.
- Continuity: the full length of the flight, ending in a return to the wall or a newel post. The 2024 edition allows a return gap of up to 1/4 in.
Setting the handrail on site
Snap a line on the wall at 34 to 38 in plumb above two nosings, one at the bottom and one at the top, and mount the brackets to it. Check that the brackets land in studs; the IRC requires handrails and guards to resist a 200 lb load in any direction[1]. The stair's own geometry comes from the stair calculator, and the full set of stair rules is on the stair code page.
Frequently asked questions
What is the code height for a handrail?
34 to 38 in above the stair nosings under the IRC and IBC.
When is a handrail required on stairs?
Under the IRC, on at least one side of any flight with four or more risers.
How is handrail height measured?
Vertically from the sloped line that joins the front edges (nosings) of the treads to the top of the rail.
What is the handrail height in the UK?
900 to 1,000 mm above the pitch line under Approved Document K in England.
Sources
- 2021 International Residential Code, Chapter 3: Building Planning (R301.5, R311.7 stairways, R312 guards)
- 2024 International Residential Code, Chapter 3 (R318.7 stairways, R320 handrails, R321 guards)
- 2021 International Building Code, Chapter 10: Means of Egress (1011.5.2, 1015.3)
- Approved Document K: Protection from falling, collision and impact (2013 edition, for use in England)
- Building Standards Technical Handbook 2022: Domestic, 4.3 Stairs and ramps
- National Building Code of Canada 2020, Division B, Part 9, Section 9.8 Stairs, ramps, handrails and guards
- ABCB Housing Provisions, Part 11.3 Barriers and handrails (NCC 2022)