Measurement Categories (BS 5489-9:1996 & BS 8300-1:2018)
Critical (<2 lux): Dangerous - cannot see obstacles or people
Dangerous (2-5 lux): Below minimum for safe navigation
Poor (5-10 lux): Below 1996 urban standard
Sub-standard (10-20 lux): Below current BS 8300 requirement
Adequate (≥20 lux): Meets modern accessibility standards
Critical Failures
135
60.5% of area <2 lux
Sub-standard
80
35.9% below standards
Adequate
8
3.6% meets standards
Average Illuminance
4.4
lux (1996 minimum: 10 lux)