Staircase Compliance Checker UK

The tool checks the dimensional requirements set by UK Approved Document K Table 1.1 for each stair category: maximum rise, minimum going, maximum pitch, minimum width, headroom, maximum risers per flight, the 2R+G comfort rule, and open riser provisions. It also references Approved Document M for general access stairs in buildings other than dwellings (1200mm minimum width, 12 risers maximum per flight, both-side handrails). It does not check guarding height, handrail extensions, structural calculations, or visual contrast — for these, see the complete regulations guide.

Private: stair within a single dwelling — including loft conversion access. Most domestic projects.

Utility / General Access: common stairs in blocks of flats serving multiple dwellings, escape routes, and access for maintenance.

General Access (Doc M): day-to-day routes in buildings other than dwellings — typically subject to Approved Document M accessibility requirements. Wider treads, lower rise, both-side handrails.

Public / Assembly: places of public assembly — theatres, sports stadiums, cinemas. Strictest dimensional requirements.

No — the tool returns guidance based on Approved Document K dimensional rules. Final compliance is determined by the relevant Building Control body on a project-by-project basis, taking into account site-specific factors that the tool cannot assess: existing structure, host building condition, conservation area constraints, listed building status, fire safety strategy, and so on. The tool is highly accurate for the dimensional checks it performs, but a passing result here does not replace Building Control sign-off. For complex projects, engage a qualified building inspector or structural engineer at design stage.

The "rule of 18" — a comfort guideline within Approved Document K. The formula 2 × Rise + Going should fall between 550mm and 700mm for stairs to feel comfortable to climb and descend. A staircase with 200mm rise and 240mm going gives 2(200) + 240 = 640mm, comfortably within range. A staircase with 220mm rise and 220mm going gives 660mm — at the limit. Outside this range, stairs feel either cramped (low value) or tiring (high value). The rule applies universally regardless of category and is one of the most commonly missed compliance checks.

Open riser stairs (no vertical panel between treads) trigger two additional Doc K rules: (1) the gap between treads must not allow a 100mm sphere to pass through (child safety) and (2) each tread must overlap the one below by 16mm minimum. The tool flags open risers because the user needs to confirm both rules separately — the tool checks dimensions but cannot verify the physical overlap and sphere clearance. For modern floating staircases and central spine designs with open risers, the 100mm sphere rule and 16mm overlap rule are the two requirements that determine Building Control sign-off. Continox open-riser staircases are designed to satisfy both as standard.

Loft conversions have specific exceptions under Doc K: (1) reduced headroom may be permitted (1800mm minimum at the low-ceiling side, 1900mm in the centre), provided the conversion is into a previously non-habitable loft and the staircase is the only practicable option; (2) alternating tread stairs (paddle stairs / space saver stairs) may be used in single-room loft access where there is insufficient space for a normal stair. These exceptions are subject to Building Control approval. The tool flags headroom below 2000mm as a warning rather than an outright fail because of the loft exception. See the full regulations guide for detail on loft conversions, alternating tread stairs and BS 5395-2 spiral stairs.

Yes — Approved Document K applies to internal and external steps and stairs that are part of the building. For external staircases, the same rise / going / pitch limits apply, with additional considerations for external tapered treads (going measured at the pitch line, minimum 280mm), corrosion protection, drainage, and slip resistance. For external fire escape staircases specifically, Approved Document B and BS 9991 add further requirements on width, enclosure and means of escape — covered in our fire escape staircase price calculator and the external staircase cost guide.