This measure, aimed primarily at industrial, commercial and institutional establishments, will better protect the territory’s ecosystems and biodiversity, increase road safety, promote public health and improve energy efficiency.

Just as we did last June with our bylaw to protect birds, we are proud to be once again the first in Montréal to adopt measures deigned to control and limit light pollution. This is an initiative that goes to the heart of sustainable development, since it not only protects biodiversity, but also increases road safety and improves the health and quality of life of Saint-Laurent residents and workers on our territory. I dare say that our Administration is very bright and that Council is making enlightened decisions!

Negative impacts of light pollution

Light pollution refers to the excessive or inappropriate use of artificial light. Light pollution is particularly prevalent in Saint-Laurent, since 70% of its territory is devoted to industrial and commercial activities and it is situated next to the Montréal-Trudeau international airport and several highways, including the CN rail yard. 

Light pollution can result in a number of adverse effects on quality of life and the environment. Already known for its impact on the night sky, it also has harmful effects on biodiversity and ecosystems, by altering the interactions between plants and pollinators or between prey and predators, hindering foraging, reproduction or migration. The glare it generates also has a negative impact on the safety of pedestrians and motorists. In addition, light pollution wastes energy and therefore increases the production of greenhouse gases. Last but not least, it poses a risk to human health by upsetting the body’s biological clock.

New requirements

Bylaw RCA08-08-0001-170 amending zoning bylaw RCA08-08-0001 aims to control and limit light pollution on private property, without compromising the safety and comfort provided by lighting and taking into account the specific characteristics of the territory. 

It covers four areas of intervention: colour, orientation, period and quantity of light, according to the following principles:

• Define situations that allow the use of bluish light.
• Direct light flows towards the ground.
• Reduce certain lighting devices after 11 p.m.
• Set maximum light levels according to land use.

The bylaw amendment is based on best practices and the most innovative approaches, notably the Bureau de normalisation du Québec’s “Éclairage extérieur – contrôle de la pollution lumineuse” standard 4930-100 (R2023), published in 2016, and the experience of the Mont-Mégantic International Dark Sky Reserve.

Buildings concerned

The new requirements regulate light pollution in Saint-Laurent for the following categories:

• Industrial (I), commercial (C) and service (S) buildings 
• Multi-family dwellings (h4), multi-family service dwellings (h5) and multi-bedroom dwellings (h6)

Given that Saint-Laurent has no power to act on light sources emanating from highways, the airport and the rail yard, the new bylaw mainly targets commercial and industrial establishments, with provisions applicable to building lighting, outdoor parking spaces, signs and billboards. Light flows must be directed towards the ground and the colour of light sources must be limited. In addition, aside from certain exceptions, lighting intensity must be reduced between 11 p.m. and 6 a.m.

Similarly, curtains are required for greenhouses on industrial roofs with lighting systems.

Single-family (h1), two-family (h2) and multiplex (h3) uses are therefore exempt, as are certain types of equipment, such as light fixtures with motion detectors, or temporary outdoor lighting for special activities: outdoor shows, festivities organized by the borough, construction areas or other temporary work projects. Other exemptions are established for outdoor lighting related to public safety or for enhancing a heritage building. 

LED lighting on public property: 90% of the transition completed in Saint-Laurent

Since 2017, Ville de Montréal has been transitioning its public lighting from sodium to light-emitting diode (LED) lighting. In Saint-Laurent, the project will soon be completed, as 90% of equipment was replaced by the end of 2023 and this figure currently stands at 98% for streets. Converting to LEDs also saves 60% on the monthly electricity bill.

With regard to public spaces, Ville de Montréal has also drawn up the Guide d’aménagement durable des rues de Montréal (a guide to sustainable street design in Montréal).

These new measures, which are part of the Montréal 2030 vision, also meet the second and third objectives of Saint-Laurent’s 2021-2030 Climate Emergency Plan, namely to reduce collective greenhouse gas emissions and protect biodiversity to increase resilience to climate hazards.

Related links 

• Outdoor lighting in Saint-Laurent
• Saint-Laurent’s 2021-2030 Climate Emergency Plan
• Saint-Laurent’s Biodiversity Corridor
• Bird Protection Takes Off in Saint-Laurent! (press release issued on June 26, 2024)
• Guide to sustainable street design in Montréal (in French)
• Guide to good lighting practices in Mercier-Hochelaga-Maisonneuve (in French)