ONLINE VERSIONStairs and laddersK11.3 In a flight of steps, for all steps use the measurements for rise and going given for the three stair categories in Table 1.1 below. Use any rise between the minimum and maximum with any going between the minimum and maximum, that complies with the relevant note contained in table 1.1. Table 1.1 Rise and goingRise* Going*Minimum (mm)Maximum (mm)Minimum (mm)Maximum (mm)1, 2Private stair 150 220 220 300Utility stair 150 190 250 400General access 150 170 250 4003stairNotes:[1] The maximum pitch for a private stair is 42°.[2] For dwellings, for external tapered steps and stairs that are part of the building the going of each step should be a minimum of 280mm.[3] For school buildings, the preferred going is 280mm and rise is 150mm.* The normal relationship between the dimensions of the rise and going is: twice the rise plus the going (2R + G) equals between 550mm and 700mm.For existing buildings the dimensional requirements in Table 1.1 should be followed, unless due to dimensional constraints it is not possible. Any alternative proposal should be agreed with the relevant building control body and included in an access strategy (refer to Approved Document M).Stepped gangways in assembly buildings1.4 The guidance provided in this document covers stairs or ramps that form part of the means of access within an assembly building such as a sports stadium, theatre or cinema. However, if steps are part of the gangways to areas for spectators, the gangways may need to be at different pitches to maintain sightlines for spectators – this may affect the main stairs. Apply all of the following guidance.a. Ensure that the maximum pitch for gangways to seating areas for spectators is 35°.b. Align the ends of all rows of seats/wheelchair spaces so that the width of the gangway remains the same.c. Provide transverse gangways to give access from the side to storey exits (vomitory exits) within the body of a seating layout.d. Ensure that transverse gangways and radial gangways in auditoria with tiered seating do not cross. Offset the connections between transverse gangways and radial gangways so that the flow of people to the exits is smooth.e. In stepped tiers, use the following measurements for each step in the gangway:(i) minimum height: 100mm(ii) maximum height: 190mm If there are two or more rises to each row of seats, make each step an equal height.f In a tier that is uninterrupted by cross-gangways, and where the pitch exceeds 25°, use a maximum number of steps of 40.Building Regulations 2010 Approved Docu Approved Docu Approved Docu Approved Document K, 2013 edition 5ONLINE VERSIONONLINE VERSIONONLINE VERSION