Arrêté 27/12/2018

Light pollution law

The French government, with the law decree of 27 December 2018, has adopted a legislative provision for the reduction and limitation of light pollution, aimed at night skies preservation, intrusive light limitation, protection of biodiversity and increase of energy savings. These goals are reached through the regulation of four features of lighting fixtures and systems, which are: ULR (Uplight Lighting Ratio), CIE flux code n°3, colour temperature and light flux density.
In addition, specific requirements are prescribed for astronomical observation areas, national parks and nature reserves.

ULR

ULR (Uplight Lighting Ratio) represents the percentage of light flux emitted upwards by a lighting fixture.
Limiting the ULR value allows to protect night skies, which observation is in fact compromised by upward directed light, detrimental for astronomical observatories and amateur astronomers.

	Fixture position
	Horizontal	Tilted
Lighting installations (both public and private) as roads, which assure drivers, cyclists and pedestrians’ safety. Outdoor and semi-indoor parking lots.	< 1%	< 4%
Lighting installations of any kind, if located within a 10 km radius from an astronomic observatory or inside a nature reserve or a national park.	= 0%	= 0%
Architectural lighting of cultural assets. Architectural and landscape lighting of parks and gardens, both public and private. Sport venues. Temporary light installations for shows and events.	-	-

CIE N°3

CIE flux codes are a photometric parameter made up of five integers (e.g. 32 74 97 100 100), which define the light distribution of a lighting fixture within certain angles.
The third integer denotes the percentage of light flux emitted within an opening semi-angle of 75,5°.
Limiting the flux emitted above 70 ÷ 75° contributes to reduce glare and intrusive light, that is the fraction of light flux directed outside the areas which need to be lit.

Lighting installations (both public and private) as roads, which assure drivers, cyclists and pedestrians’ safety. Outdoor and semi-indoor parking lots.	> 95%
Architectural lighting of cultural assets. Architectural and landscape lighting of parks and gardens, both public and private. Sport venues. Temporary light installations for shows and events.	-

COLOUR TEMPERATURE (K)

Some features of the artificial light spectrum can affect biological cycles of flora and fauna.
To preserve biodiversity, the decree sets the maximum colour temperature of the light sources to be used.

	Colour temperature (K)
	Urban areas	Extra-urban areas
Lighting installations (both public and private) as roads, which assure drivers, cyclists and pedestrians’ safety. Non-residential buildings (e.g. commercial and industrial facilities), included indoor lighting which is emitted outdoor. Outdoor and semi-indoor parking lots.	≤ 3000 K	≤ 3000 K
Architectural lighting of cultural assets. Architectural and landscape lighting of parks and gardens, both public and private. Sport venues. Temporary light installations for shows and events.	-	-
Lighting installations of any kind inside nature reserves.	≤ 2400 K	≤ 2400 K
Lighting installations of any kind inside national parks.	≤ 2700 K	≤ 2400 K

LIGHT FLUX DENSITY (lm/m²)

Light flux density is the ratio between the summation of the fluxes of all the lighting fixtures which light up a certain area and the surface of the area itself; its measure unit is lm/m².
It allows to evaluate if an installation lights up only where it’s needed without wastes, so to increase energy savings.

	Light flux density (lm/m²)
	Urban areas	Extra-urban areas
Lighting installations (both public and private) as roads, which assure drivers, cyclists and pedestrians’ safety.	< 35 lm/m²	< 25 lm/m²
Architectural and landscape lighting of parks and gardens, both public and private.	< 25 lm/m²	< 10 lm/m²
Non-residential buildings (e.g. commercial and industrial facilities), included indoor lighting which is emitted outdoor.	< 25 lm/m²	< 20 lm/m²
Outdoor and semi-indoor parking lots.	< 25 lm/m²	< 20 lm/m²

Arrêté 27/12/2018

Light pollution law

ULR

CIE N°3

COLOUR TEMPERATURE (K)

LIGHT FLUX DENSITY (lm/m²)

See also