Fit a handrail at the wrong height and it stops doing its job — too low and it offers nothing on the way down, too high and anyone leaning on it for balance overbalances instead. For older or disabled households retrofitting a staircase, the numbers matter more than the finish. Here is what the UK’s Building Regulations actually say about handrail height, second rails, and how a grab rail should be fixed — set out plainly, without the sales pitch.
The core height range: 900mm to 1000mm
Approved Document K (Protection from falling, collision and impact) and Approved Document M (Access to and use of buildings) both govern handrail height, and between them they set a working range rather than one fixed figure. For stairs and landings generally, the top of the handrail should sit between 900mm and 1000mm — measured from the pitch line of the stairs (the imaginary line touching the front edge, or nosing, of each step) or from the finished floor level on a landing.
Approved Document M narrows this slightly for what it calls a "grippable" handrail — one a hand can actually close around, rather than a wide balustrade cap rail — specifying 850mm to 1000mm above the pitch line. Approved Document K, meanwhile, is more specific for ordinary homes: internal stairs should have their handrail at 900mm from the pitch line, and landings at 1000mm. Where a stair runs alongside an external balcony or a roof edge, the minimum rises to 1100mm, reflecting the greater fall risk.
Why a second, lower handrail is often the missing piece
Most retrofits stop at one handrail fitted to the standard height range above — which suits an adult of average height reasonably well, but leaves shorter adults, wheelchair users transferring on a stairlift, and anyone who needs a lower grip point for balance with nothing to hold. Approved Document M addresses this directly: it recommends a second, lower handrail positioned between 600mm and 700mm from the pitch line, originally framed around children and people of shorter stature but equally relevant to many older or disabled users. (Approved Document K applies the same idea in primary schools, setting a second handrail at 600mm.)
This is worth raising explicitly with whoever quotes for the work, because a single-handrail fit that technically satisfies the main height range can still leave a genuine gap in usability. If balance on the stairs is the actual problem being solved, a second rail at the lower height is often the change that makes the difference — not a taller or thicker version of the rail that’s already there.
One side or both: what the regulations require by stair width
The regulations also settle a common point of dispute: does a straight staircase need a handrail on both sides, or is one enough? Approved Document M sets the rule by width. Any stair with three or more risers needs a handrail on at least one side as a baseline. Once the stair is wider than 1000mm, handrails are required on both sides. The same both-sides logic applies to ramps longer than two metres. For a narrower domestic staircase, one continuous, correctly-heighted handrail can be compliant — but it’s worth checking the actual width before assuming a single rail is sufficient, particularly in older properties with unusually wide flights.
Grab rails are a different fitting — and a different fixing job
It’s easy to treat "handrail" and "grab rail" as interchangeable, but the regulations and the products themselves distinguish them. A handrail is a continuous run designed to be held while moving along a stair or ramp. A grab rail is shorter — typically 30 to 60cm — and provides targeted support for a specific movement, such as steadying a sit-to-stand transition. Councils and occupational therapists routinely reference Approved Document M and the related British Standard (BS 8300) when assessing where a grab rail should go and how it should be fixed, which is why an OT assessment is worth having before any grab rail is installed, not just before a full stairlift or ramp goes in.
The fixing standard is the part that gets skipped most often on DIY jobs. A support rail needs to be anchored into a structural substrate capable of taking real pulling force from any direction — not simply screwed into plasterboard. Baseline safety standards require that a correctly anchored rail withstand at least 113kg of static load. That figure only means anything if the installer has actually identified what’s behind the wall and used fixings rated for it; a rail that looks solid but is fixed into the wrong substrate can fail exactly when someone puts their full weight on it in a fall.
The smaller details that get inspected
A handful of secondary specifications turn up repeatedly in Approved Document M guidance and are worth checking on any quote:
- Wall clearance: at least 50mm between the handrail (or grab rail) and the adjacent wall surface, so a hand can wrap fully around it.
- Profile: circular, 40mm to 50mm in diameter, or oval with a 50mm width — thin enough for an arthritic or weaker hand to close around securely.
- Contrast and touch: the rail should contrast visually against the wall behind it, and shouldn’t be cold to the touch — both practical points for anyone with reduced vision or sensation.
| Location | Height requirement | Source |
|---|---|---|
| Internal stairs (domestic) | 900mm from pitch line | Approved Document K |
| Internal landings | 1000mm from floor level | Approved Document K |
| Grippable handrail, general | 850–1000mm above pitch line | Approved Document M |
| Balconies / roof edges | 1100mm minimum | Approved Document K |
| Second, lower handrail | 600–700mm from pitch line | Approved Document M |
Ask the right question before you commission the work
The regulations exist so that a handrail or grab rail actually does its job under load, at the right height, for the person using it — not so that a fitter can tick a box. Before signing off any quote, it’s reasonable to ask directly: what height will the main handrail sit at, is a second lower rail being fitted, and what is it being fixed into? A tradesperson working to Approved Document K and M standards should be able to answer all three without hesitation. If they can’t, that’s the moment to get a second opinion — not after the rail is on the wall.