Staircase building regulations: Wales
Written by Scott Jones, The Stair Guys, independent staircase measuring and sourcing specialists·Last updated
Wales has run its own suite of Approved Documents since April 2017, published by the Welsh Government. For everyday stair geometry, the good news is simple: the Welsh Approved Document K (2017) mirrors the England Approved Document K, so the rise, going, pitch, width, headroom, handrail and guarding figures are the same as England's. The real difference between the two nations is not the shape of the stair. It is accessibility.
The geometry: the same as England
Because the Welsh Approved Document K follows the England document, the figures are the ones set out in our main guide: a private stair with a rise up to 220mm, a going of at least 220mm, a maximum pitch of 42 degrees, and the general access and utility categories for shared and public buildings. For the full numbers see private staircase dimensions and the UK staircase building regulations guide, which hold for Wales as well as England.
The real difference: accessibility and M4
England has, since 2015, split its accessibility rules into three tiers, M4(1), M4(2) and M4(3), where a planning condition can require the higher tiers. The higher tiers bring in things like a minimum 850mm stair width to allow a future stairlift. Wales did not adopt that system. Welsh Approved Document M remains the single, earlier accessibility standard (the 2004 edition with 2010 and 2022 amendments), with no M4(2) or M4(3) optional categories. So there is no automatic 850mm stairlift-width rule and no through-floor lift reservation built into the Welsh building regulations for an ordinary dwelling.
Where accessible-housing rules do come from in Wales
That does not mean accessibility is ignored in Wales. Where accessible or adaptable homes are required, it comes through the planning system, from a Local Development Plan policy imposed as a planning condition, rather than through the building regulations. If your project is subject to such a condition, the local planning authority will set the standard it wants (often referencing accessible-housing criteria comparable to M4(2)), and building control enforces against that condition. So in Wales the question to ask is not just "does it meet the building regs" but "is there a planning condition on accessibility", because that is where any stairlift-width or adaptability requirement will sit.
Frequently asked
Are the staircase building regulations different in Wales?+
For stair geometry, no in practice: the Welsh Approved Document K (2017) mirrors England's, so rise, going, pitch, width, headroom, handrails and guarding are the same. The real difference is accessibility, where Wales follows a different, earlier Approved Document M to England.
Does Wales use England's M4(2) and M4(3) accessibility standards?+
No. Wales never adopted England's M4(2)/M4(3) optional requirements. Welsh Approved Document M remains the single earlier accessibility standard (2004 edition with 2010 and 2022 amendments), so there is no built-in 850mm stairlift-width rule or through-floor lift reservation in the Welsh building regulations for an ordinary dwelling.
Is there an accessible-housing requirement for stairs in Wales?+
Where one applies, it usually comes through the planning system rather than the building regulations, as a Local Development Plan policy imposed by planning condition. The local planning authority sets the standard and building control enforces against that condition, so it is worth checking whether your project carries such a condition.
Sources
Primary sources we used and reconciled before publishing.
Related guides
- UK Staircase Building Regulations, ExplainedThe building regulations for stairs in England, Wales, Scotland and Northern Ireland, in plain English. Rise, going, pitch, headroom, guarding and handrails, every figure sourced.
- Staircase headroom: how much you need and how to check itHow much headroom a staircase needs under UK building regulations: the 2 metre rule, the reduced loft-conversion allowance, where headroom is tightest, and how to check it properly.
- Staircase handrail requirements: height, sides and gripWhat UK building regulations require of a staircase handrail: the 900mm to 1000mm height, when you need one side or both, and why a wall-mounted rail needs proper clearance and grip.
- Staircase guarding and balustrade: height and the 100mm ruleWhat UK building regulations require of staircase guarding and balustrade: where it is needed, the 900mm height, the 100mm sphere gap rule, and why it must not be easy for a child to climb.
- Private staircase dimensions: rise, going and pitchThe rise, going and pitch rules for a private (domestic) staircase in the UK, the 2R+G formula, why every rise must be equal, and the simple going = rise divided by 0.9 rule of thumb that keeps a stair within 42 degrees.
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