The following are key terms used in this document:
An entrance which is accessible to people regardless of disability, age or gender.
Alternating tread stair
A stair with paddle-shaped treads where the wide portion is on alternate sides on consecutive treads (see paragraphs 1.29 and 1.30).
A structure – either a raised rail or a solid wall – that denies access to another area.
Serving more than one dwelling.
The perception of a visual difference between two elements of the building, or fittings within the building, so that the difference in light reflectance value is of sufficient points to distinguish between the two elements.
A continuous series of steps or a continuous slope (ramp) between landings. (For the widths and lengths of flights see paragraphs 1.14–1.24.)
General access stair
A stair intended for all users of a building on a day-to-day basis, as a normal route between levels.
For stairs: the depth from front to back of a tread, less any overlap with the next tread above (see paragraphs 1.2 and 1.3). (For the measurement of the going on tapered treads see paragraphs 1.25– 1.27.)
For ramps: the length of the ramp between landings.
A barrier that denies pedestrians or vehicles access to another area, for example the floor below (see Diagrams 3.1 and 3.2).
A rail, at hand height or a little higher, for people to hold for support. (For handrails for stairs, see paragraphs 1.34–1.37; for handrails for ramps, see paragraphs 2.11–2.12.)
A stair in a helix around a central void (see paragraph 1.28).
A means of access to another level, formed by a series of rungs or narrow treads. People normally ascend or descend facing the ladder. (See paragraphs 1.31–1.33.)
Light reflectance value (LRV)
The total quantity of visible light reflected by a surface at all wavelengths and directions when illuminated by a light source.
The leading edge of a stair tread.
The angle of inclination (slope) between the horizontal and a line connecting the nosings of a stair.
A stair intended to be used for only one dwelling.
An entrance which a visitor not familiar with the building would normally expect to approach.
A gangway at an angle to the rows of seats/wheelchair spaces or a stepped gangway in tiered seating.
A slope steeper than 1:20, on which a pedestrian or wheelchair user can move from one level to another (see Section 2).
The height between consecutive treads (see paragraphs 1.2 and 1.3).
For ramps: the vertical distance between each end of the ramp flight.
A stair in a helix around a central column (see paragraph 1.28).
The clear width between the walls or balustrades. Tapered tread
A step in which the going reduces from one side to the other (see paragraphs 1.25–1.27).
A flat gangway parallel to the rows of seating/wheelchair spaces.
A stair used for escape, access for maintenance, or purposes other than as the usual route for moving between levels on a day-to-day basis.
Storey exits provided within the body of a seating layout.