ISO 21542:2021

Overview

ISO 21542:2021 - Building construction: Accessibility and usability of the built environment - is the Slovenian adoption of ISO 21542:2021. It specifies requirements and recommendations for the design and construction of building elements, assemblies, components and fittings that affect access to buildings, circulation within buildings, egress under normal conditions, and evacuation in fire. The standard applies to new buildings and new work in existing buildings, and covers common spaces in multi‑unit residential buildings (with recommendations for residential units in Annex A). It also addresses outdoor features directly related to building access while excluding unrelated public open spaces.

Key topics and technical requirements

ISO 21542:2021 covers a wide range of accessibility and usability issues, including:

• Approach and entry
  • Accessible parking, drop‑off zones and signage
  • Paths to buildings, ramps, kerb ramps and drainage
• Horizontal and vertical circulation
  • Internal corridors, manoeuvring and turning spaces for wheelchairs
  • Ramps, stair design, handrails, lifts and moving walks
• Entrances and thresholds
  • Space and clearance requirements, vestibules, final fire exits
• Orientation, wayfinding and information
  • Levels of information, tactile walking surface indicators (TWSI), tactile maps
  • Signage, font sizes, placement, luminance contrast and Braille
• Visual and lighting considerations
  • Surface finishes, visual contrast, glare control, light levels for wayfinding
• Acoustics and communication
  • Noise control, hearing enhancement systems and emergency warnings (audible and visual)
• Emergency systems
  • Audible and visual signals and information for evacuation and fire response
• Design assumptions
  • Wheelchair footprint reference (800 mm wide × 1 300 mm long) based on ISO 7176‑5 and ISO/TR 13570‑2
• Existing buildings
  • Concept of “exceptional considerations for existing buildings” to define acceptable, limited accessibility where full compliance is technically or economically infeasible - not to be overused.

Practical applications and who uses it

ISO 21542:2021 is essential for:

• Architects, building designers and engineers specifying accessible layouts
• Accessibility consultants and universal design specialists
• Facility managers and building owners implementing retrofits
• Product manufacturers (doors, lifts, ramps, signage) ensuring usability compliance
• Regulators and code officials aligning national building codes with international accessibility standards

Use the standard to inform building specifications, tender documents, accessibility audits, and inclusive design strategies for the built environment.

Related standards

• ISO 21542:2021 (original international document)
• ISO 7176‑5 and ISO/TR 13570‑2 (wheelchair dimensions and user data)
• National building codes and accessibility legislation (for local compliance)

Keywords: ISO 21542:2021, accessibility, built environment, usability, building construction, ramps, signage, tactile, wheelchair access, wayfinding, universal design.