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ISO 28564-3: Location Identification — Part 3: Signs
Design principles, graphical symbols, and placement requirements for location identification signage
1. Scope and Design Principles of ISO 28564-3
ISO 28564-3 specifies the design principles, graphical symbols, and placement requirements for location identification signage in public buildings, transportation hubs, commercial facilities, and industrial complexes. This standard harmonises sign layouts, colour coding, typography, and pictogram styles to create a universally understandable wayfinding system that serves diverse populations including international visitors, elderly persons, and people with visual or cognitive impairments.
When selecting typefaces for signage, use humanist sans-serif fonts (e.g., Frutiger, Myriad, or Clearview) rather than geometric sans-serifs. Studies show humanist fonts improve legibility for dyslexic readers by 30–40 % due to more distinctive character shapes.
| Parameter | Minimum Requirement | Recommended Best Practice |
|---|---|---|
| Pictogram height (indoor) | 75 mm | 100–150 mm (dependent on viewing distance) |
| Text character height | 15 mm (per 10 m viewing distance) | 20 mm + 2 mm per additional 10 m |
| Luminance contrast ratio | 3:1 (background to text/symbol) | 5:1 minimum; 7:1 recommended |
| Illuminance at sign face | 50 lx | 150–300 lx (uniformity ≥ 0.6) |
| Letter spacing (tracking) | −5 % to +10 % of font width | +5 % tracking for enhanced legibility |
| Maximum text line length | 60 characters | 40–50 characters per line |
| Mounting height (floor to centre) | 2.0 m (indoor corridors) | 2.2–2.5 m (consistent throughout facility) |
2. Sign Categories and Placement Strategies
ISO 28564-3 classifies location identification signs into three functional categories: directional signs (wayfinding arrows with destination names), locational signs (identifying rooms, departments, or functional areas), and informational signs (hours of operation, services available, accessibility features). Each category uses a distinct visual hierarchy: directional signs use a blue background with white text and arrows (as defined in ISO 28564-3 §6.2), locational signs use white backgrounds with dark text, and informational signs use green backgrounds for general information or yellow for cautionary information.
A common compliance failure is placing directional signs at decision points (junctions, corridor intersections) that are already visible from more than 20 m away but lack adequate advance warning. Install advance directional signs at 10–15 m before the decision point, not at the point itself.
Wayfinding cognitive load theory underpins the placement strategy. Research cited in the standard indicates that a person can process a maximum of 3–5 destination names on a single directional sign before experiencing decision paralysis. For complex facilities (hospitals, airports), implement a hierarchical wayfinding system: primary signs list major zones only, secondary signs list sub-destinations within each zone, and tertiary signs provide room-level identification.
3. Material Selection and Engineering Design
Sign durability and maintainability are critical in high-traffic environments. The standard specifies minimum performance requirements for sign substrates, including impact resistance (IK07 for indoor, IK10 for outdoor per IEC 62262), UV stability (≥ 5 years outdoor exposure without significant fading), and fire rating (class B-s1,d0 per EN 13501 for indoor installations).
- Illuminated signs: Edge-lit acrylic panels with LED strips (colour temperature 4000–5000 K, CRI ≥ 80) provide uniform luminance with 30–50 % lower power consumption than fluorescent backlit panels. LED lifetime should exceed 50,000 hours to ≥ 70 % lumen maintenance.
- Tactile elements: For accessibility compliance, signs at accessible heights (900–1100 mm from floor) must include tactile characters and Braille per ISO 28564-3 Annex A. Braille dots must have a base diameter of 1.5–1.6 mm, height of 0.6–0.8 mm, and interdot spacing of 2.3–2.5 mm.
Using photoluminescent materials (strontium aluminate SrAl₂O₄:Eu,Dy based) for exit and safety signage eliminates the need for emergency backup wiring while maintaining ≥ 60 minutes of visible luminance after power loss, satisfying most building code requirements.
Never use mirrored or highly reflective surfaces as sign substrates. Reflections can create glare that renders the sign unreadable for elderly persons and can completely obscure information for people with contrast sensitivity losses — a condition affecting over 30 % of adults aged 65+.
4. Frequently Asked Questions
Q: Are the sign specifications in ISO 28564-3 legally enforceable?
A: ISO 28564-3 is a voluntary international standard. However, many national building codes (e.g., IBC in the US, Building Regulations Part M in the UK) reference this standard as an approved method of compliance for accessible wayfinding.
A: ISO 28564-3 is a voluntary international standard. However, many national building codes (e.g., IBC in the US, Building Regulations Part M in the UK) reference this standard as an approved method of compliance for accessible wayfinding.
Q: How does the standard address multilingual signage?
A: The standard recommends stacking languages vertically rather than horizontally, with the local language in the top position. A maximum of three languages per sign is advised to maintain legibility. Pictograms should be used as the primary communication method with text as secondary support.
A: The standard recommends stacking languages vertically rather than horizontally, with the local language in the top position. A maximum of three languages per sign is advised to maintain legibility. Pictograms should be used as the primary communication method with text as secondary support.
Q: What is the recommended contrast ratio for signage in heritage buildings where mounting bracket modifications are restricted?
A: In heritage settings where physical sign modifications are constrained, achieve the required 3:1 luminance contrast ratio through LED task lighting directed at the sign face rather than modifying the sign substrate itself. Ensure the lighting does not exceed 300 lx on the sign surface to avoid glare.
A: In heritage settings where physical sign modifications are constrained, achieve the required 3:1 luminance contrast ratio through LED task lighting directed at the sign face rather than modifying the sign substrate itself. Ensure the lighting does not exceed 300 lx on the sign surface to avoid glare.
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