ONLINE VERSIONK1 Section 1: Stairs and laddersSteepness of stairs – rise and goingDiagram 1 Measuring rise and going1.1 The requirement will be satisfied if, in a See paras 1.3–1.5flight, the steps all have the same rise and the same going to the dimensions shown in 1.3 or comply with 1.4 and 1.5.1.2 Three categories of stairs are considered in this Approved Document: ‘Private’ intended to be used for onlyone dwelling. ‘Institutional and assembly’ serving a place where a substantial number of people will gather. ‘Other’ in all other buildings.1.3 Indication of the practical limits for rise and going, for each category of stair which 1.5 The normal relationship between the satisfies the requirements, is given below.dimensions of the rise and going is that twice the a. Private stair: Any rise between 155mm and rise plus the going (2R + G) should be between 220mm used with any going between 245mm 550mm and 700mm.and 260mm; orDiagram 1 shows how to measure the rise and Any rise between 165mm and 200mm used going (for steps with tapered treads, see also with any going between 223mm and 300mm.paragraphs 1.18–1.20).b. Institutional and assembly stair: Any rise 1.6 In assembly buildings, the gangways may between 135mm** and 180mm** used with need to be at different pitches to maintain any going between 280mm and 340mm.sightlines for spectators and this may affect the main stairs, etc.c. Other stair: Any rise between 150mm** and 190mm** used with any going between The maximum pitch for gangways for seated 250mm and 320mm.spectators is 35º.1.4 Table 1 gives the maximum rise and Alternative approachminimum going for the three stair categories.1.7 The requirement for steepness of stairs can be met by following the relevant recommendations in BS 5395-1:1977 Stairs, Table 1 Rise and goingladders and walkways. Code of practice for the design of straight stairs.Maximum Minimum rise going Construction of steps(mm) (mm)1.8 Steps should have level treads. Steps1.Private stair 220† 220†may have open risers, but treads should then overlap each other by at least 16mm. For steps 2.Institutional and 180** 280*in buildings providing the means of access for assembly stairdisabled people reference should be made to 3.Other stair 190** 250Approved Document M, Access and facilities for disabled people.1.9 All stairs which have open risers and are Note:likely to be used by children under 5 years should be constructed so that a 100mm diameter sphere † The maximum pitch for private stair is 42º.cannot pass through the open risers.* If the area of a floor of the building is less 2than 100m, the going may be reducedto 250mm.** For maximum rise for stairs providing the means of access for disabled people, reference should be made to Approved Document M: Access and facilities for disabled people.Stairs, ladders and ramps Approved Document K6ONLINE VERSION