Semi-Cylindrical Illuminance in CJJ 45, JGJ/T 163 and GB/T 50034
Summary: Esc is now embedded in Chinese road, nightscape and building lighting standards. This article maps definitions, evaluation metrics and example limit values from CJJ 45-2015, JGJ/T 163-2008 and GB/T 50034—2024, and links them to measurement standards such as GB/T 5700. Always verify against the official text.
CJJ 45-2015: why sidewalks require Esc
Pedestrian and non-motorized lanes shall be evaluated using average/min horizontal illuminance, vertical illuminance, semi-cylindrical illuminance and glare limits.
Example maintained values from Table 3.5.1-1 (lx): Level 1 Esc,min 3; Level 2: 2; Level 3: 1.5; Level 4: 1. Measurement height: 1.5 m above pavement on the road centre line.
JGJ/T 163-2008: nightscape plazas and parks
Outdoor public spaces such as walkways and plazas should use Eh plus Esc at 1.5 m. Park examples include Esc,min of 2 / 3 / 4 lx for walkways, courtyards and children’s play areas respectively (see official tables).
GB/T 50034—2024
The 2024 building lighting design standard adds Esc terminology and minimum Esc requirements for outdoor public areas of residential and public buildings.
Measurement standards
Pair design limits with GB/T 5700 (field methods), GB/T 39388 / CIE S 023 (meter characterization) and appropriate calibration practice. See the calibration article and solution page.
FAQ
Q: What Esc limits does CJJ 45 give for sidewalks?
A: Example maintained Esc,min values: Level 1 = 3 lx, 2 = 2 lx, 3 = 1.5 lx, 4 = 1 lx at 1.5 m on the centre line. Always verify against the official text.
Q: Is horizontal illuminance alone enough for acceptance?
A: No—where Esc is a listed evaluation metric (sidewalks, nightscape walkways/plazas), acceptance must include Esc.
Q: What does GB/T 50034—2024 add for Esc?
A: It adds Esc terminology and minimum Esc for outdoor public areas of residential/public buildings, so outdoor lighting acceptance increasingly checks Esc.
