In order to facilitate orientation and to ensure safe use of an environment, adjacent surfaces, information and potential hazards shall provide a discernible visual contrast.
A minimum difference in LRV shall be provided in relation to the visual task in accordance with Table 11. Additionally, one of the two surfaces should have an LRV value of minimum 30 points for door furniture, 40 points for large area surfaces and 70 points for potential hazards and text information.
The minimum difference in the LRV shall be achieved and maintained throughout the life of the building elements. Deterioration and maintenance shall be considered at installation.
For lighting conditions lower than specified in this Code, the difference in LRVs should be higher.
NOTES
1 The LRV, sometimes also called the luminance reflectance value, or CIE Y value, is expressed on a scale of 0-100, with a value of 0 points for pure black and a value of 100 points for pure white.
2 The perception of visual contrast increases with better lighting conditions.
3 Reflections and glare from shiny surfaces can reduce visual contrast and can confuse people with vision impairments.
NOTE — Fig. 118 is a combination sign which combines a safety sign and one or more associated supplementary signs on the same rectangular carrier. The signs used in the figure are the following:
a) Running man (centre of the combination sign) — Emergency exit (right hand).
b) Arrow (right) — Supplementary arrow sign used with the emergency exit sign to indicate its location in the right direction.
c) Supplementary sign (opposite to the arrow) — Full accessibility or toilets accessible.
FIG. 118 ACCESSIBLE EMERGENCY EXIT ROUTE
PART 3 DEVELOPMENT CONTROL RULES AND GENERAL BUILDING REQUIREMENTS
| Sl No.(1) | Visual Task(2) | Difference on the LRV Scale(3) | Approximate Examples of Colour Contrasting(4) |
|---|---|---|---|
| i) | Large surface areas (that is, walls, floors, doors, ceiling), elements and components to facilitate orientation (that is, handrails, switches and controls, tactile walking surface indicators, and visual indicators on glazed areas) | ≥30 points | |
| ii) | Potential hazards and self contrasting markings (that is, visual indicator on steps) and text information (that is, signage) | ≥70 points |
For door hardware (that is, the elements and components to facilitate opening and closing doors) a difference in LRV between the product and its background of at least 15 points and a minimum light reflectance value of 30 points for one of the two surfaces is acceptable.
NOTE — Door hardware is normally positioned at the same height on a door and is either on the left or right side. This makes the location of door hardware easier than other features. In addition, the three-dimensional features of door hardware create shadows and bright spots, which further enhance their location.
Floor patterns should have a visual contrast of less than 20 points difference on the LRV scale.
NOTE — Highly contrasted floor patterns can be perceived as differences in floor level, which may confuse people with vision impairments or cognition capacity. Highly contrasted floor patterns may trigger an attack of vertigo.