The main private-stair dimensions
For a private stair, the standard guidance in Table 1.1 gives a rise between 150mm and 220mm and a going between 220mm and 300mm. It also gives a maximum pitch of 42 degrees. 'Rise' is the vertical step height; 'going' is the horizontal distance between consecutive nosings, not necessarily the full depth of the tread material. [1]
The dimensions work together. The guidance checks twice the rise plus the going against a range of 550mm to 700mm. Choosing values independently at opposite ends of their ranges does not automatically produce a compliant stair. The completed flight also needs the consistency and safe layout addressed by the document. [1]
These are guidance parameters for the relevant stair type, not a complete manufacturer-ready design. Different rules and considerations apply to stairs serving more than one dwelling, and constrained existing-building situations need specific assessment. [1]
Measure headroom after construction
The normal 2-metre clearance is measured above the stair pitch line and above landings. The reduced loft detail is intended for the sloping roof situation illustrated in Diagram 1.4. It does not permit the entire width of the stair to have only 1.8 metres of headroom. [1]
The section should include the finished floor, stair, plasterboard and roof lining. The space between existing bare timbers can be misleading once the new construction is included. Fixing the stair opening and finished floor levels early helps prevent this clash. [1] [2]
Landings, handrails and guarding
Show the top and bottom landings and nearby door swings, not just the flight. The design also needs suitable handrails and protection at open edges and around the stairwell. These are part of the same safety assessment, rather than optional joinery details to choose after installation. [1]
Where a door is needed for fire protection, its position must work with the landing and escape route. A fire-compliant enclosure and a stair-compliant geometry must be achievable simultaneously. [3] [1]
Can a compact stair or ladder be used?
Approved Document K includes restricted alternatives such as alternating-tread stairs in certain loft situations. Their presence in the document does not make them a general replacement for an ordinary stair serving any number or type of rooms. Ask the designer to establish the scope of the proposed alternative before choosing it. [1]
A retractable access arrangement for storage should not be assumed suitable for a habitable conversion. The proposed use, means of escape and everyday access need a joined-up building-regulations assessment. [1] [4]
What to approve before manufacture
Review the final floor-to-floor height, number of rises, goings, pitch, headroom section, landings and guarding on one coordinated drawing. Check it against the structural opening and fire layout before placing the order. The aim is a stair that fits the completed building, not merely a product that meets a dimension in isolation. [1] [3] [2]