SIST EN ISO 10551:2020

Overview

EN ISO 10551:2019 - Ergonomics of the physical environment: Subjective judgement scales for assessing physical environments provides principles and examples for constructing valid, reliable subjective judgement scales used to assess indoor and outdoor physical environments. Published by ISO and adopted by CEN (EN ISO 10551:2019), the standard does not prescribe specific scales; instead it guides scale construction and use across environmental components such as thermal, visual, air quality, acoustic and vibration conditions.

Key Topics

• Principles of scale construction: guidance on wording, structure (including unipolar and bipolar forms), and presentation to reduce bias and improve validity and reliability.
• Types of subjective scales: perceptual, evaluative, preference, acceptability, tolerance and expressions of judgement.
• Instructions for administration: standard recommendations for instructions, repeat enquiries and format to ensure consistent data collection.
• Data handling and analysis: guidance on applying results from subjective ratings for evaluation and comparison.
• Annexed examples: commonly used scales and worked examples for thermal, acoustic, visual, vibration and air quality environments (informative annexes).
• Scope limits: explicitly excludes scales related to reading/display performance, manual performance, psychological mood, pain, injury-inducing stimuli and does not cover questionnaire design (see ISO 28802 for environmental survey procedures).

Applications

EN ISO 10551 is intended for professionals who need to assess human responses to physical environments, including:

• Ergonomists and human factors specialists conducting comfort and satisfaction studies.
• Building designers, architects and facility managers performing post-occupancy evaluations and indoor environmental quality (IEQ) assessments.
• HVAC and lighting engineers, acoustic and vibration consultants integrating occupant feedback with physical measurements.
• Occupational health & safety practitioners and researchers investigating environmental stressors and human perception. Practical uses include occupant surveys, field studies, laboratory experiments, diagnostic assessments of problematic environments, and supporting decisions to improve comfort, acceptability and performance.

Related standards

• ISO 28802 - Environmental surveys (complements EN ISO 10551 by covering survey procedures and includes scales based on the principles in this document).
• Part of the ISO series on assessment of comfort, stress and strain in physical environments (ISO/TC 159 ergonomics).

Using EN ISO 10551 helps create consistent, comparable subjective data on thermal comfort, noise annoyance, air quality perception, lighting satisfaction and vibration disturbance - improving evidence-based decisions for healthier, more comfortable environments.