Many stair railing articles mix up handrails, balustrades, guard rails and decorative banisters. For a home renovation, the useful question is simpler: can someone grip the rail, is it at the right height, are open edges protected, and are the gaps safe for children?
Stair railing height quick table
| Check | Practical UK guide | What to do before fitting |
|---|---|---|
| Handrail height | 900mm to 1000mm to the top of the handrail, measured from the pitch line or floor | Measure the finished stair line, not the old rail bracket holes. |
| Stair width | If the stairs are 1000mm or wider, provide a handrail on both sides | Measure the clear width after plaster, strings, panelling and any trims. |
| Guarding on domestic stairs | Guard the sides of flights and landings where the drop is more than 600mm | Do not treat a low decorative rail as guarding if the open edge is a fall risk. |
| Openings in guarding | Where children under five may use the stair, a 100mm sphere should not pass through openings | Check spindle gaps, side gaps at strings and the space under any bottom rail. |
| Handrail grip | The rail should give firm support, a firm grip and should not snag clothing at the ends | Choose a profile people can actually hold, not only a style that photographs well. |
Stair railing compliance checker
Use this as a pre-survey check before replacing handrails, spindles or guarding.
What changes during a renovation
Small jobs can accidentally create compliance problems. Replacing a handrail with a chunkier profile can move the top height outside the 900mm to 1000mm zone. New cladding can reduce stair width. Replacing spindles can leave a larger opening near the string. A landing that felt safe before may become a clearer fall risk once walls, doors or furniture are changed.
Keep the pitch line in mind
On a flight of stairs, the measurement is not taken vertically from one tread at random. The useful reference is the pitch line of the stair. If the stair is uneven, old or partly rebuilt, take several measurements before fixing brackets.
Do not ignore landings
A landing rail is judged from the finished floor, not from the sloped stair line. Landings also raise the guarding question if there is an open edge and a drop.
Children change the detail
The 100mm sphere rule is there because small gaps can trap or allow children through. Check between spindles, below the bottom rail and beside posts.
Grip beats decoration
A wide flat cap can look tidy but may be poor as a handrail. The rail should offer a comfortable grip and secure fixing into suitable structure.
Common mistakes we see
- Measuring from the front of a tread instead of using the stair pitch line.
- Copying the old handrail height even though new flooring or stair work has changed the finished level.
- Fitting stylish spindles with gaps that are too large for a child-used stair.
- Stopping the handrail short of the useful part of the flight.
- Fixing brackets into weak plasterboard without proper timber or masonry support.
FAQ
What height should a stair handrail be?
Approved Document K gives 900mm to 1000mm to the top of the handrail from the pitch line or floor. Check the correct local building standards for your project.
Do domestic stairs need a handrail on both sides?
If the stair is 1000mm or wider, handrails are expected on both sides. Narrower domestic stairs commonly have one handrail, but the full layout and risk still matter.
What is the 100mm sphere rule?
Where children under five may use the building, openings in guarding to a flight of stairs should not allow a 100mm sphere to pass through.
When is guarding needed on stairs at home?
For dwellings, Approved Document K points to guarding at the sides of flights and landings where there is a drop of more than 600mm.
