By Gerard Bowtell-Harris, Technical Lighting Specialist, Raylinc Lighting
Use fittings that don’t need to be tilted. Tilting a light raises the risk of it ending up where it shouldn’t. Flat mounted fittings with the right optics solve the problem at design stage, before anyone has to complain.
The standard is AS/NZS 4282:2023, Control of the obtrusive effects of outdoor lighting. Gerard Bowtell-Harris sums it up as “the control of light that comes into private residences’ windows, or habitable spaces.”
It covers single and double storey houses, multi-residential buildings and commercial residences. It also protects environmental spaces, such as observatories and habitats for flora and fauna.
The standard sets environmental zones, from intrinsically dark (A0) to high district brightness (A4). The limits depend on the zone. In every case the aim is the same: “It’s the limiting of any light that goes into those places inadvertently,” Gerard says.
The usual cause is tilt. “The immediate tilting of a light increases that potential risk for light spill,” Gerard says.
For car parks, pathways and roads, he designs with fittings that don’t tilt. They mount flat, parallel to the ground, and use optics to put the light where it’s needed.
Sports lighting is different. Those fittings have to tilt, so the design relies on well-controlled optics and AS/NZS 4282 calculations to show the light stays where it should.
The council usually receives the complaint. What happens next depends on timing.
Gerard’s protection is the design itself. If the documentation shows zero obtrusive light reaching nearby homes, and the fittings went in as designed, “all due diligence has theoretically been done.” If the fittings weren’t installed correctly, for example tilted when the design called for flat, the installing contractor carries the cost.
It is the Australian and New Zealand standard for controlling the obtrusive effects of outdoor lighting. It limits light spill into homes and sensitive environments, with limits set by environmental zone.
Most often because the fitting is tilted. Fittings mounted flat, with optics that direct the light, keep it on the road or path.
During the defects period, usually the contractor. If the fittings were installed differently from the design, the installing contractor typically carries the cost.
No. The standard also covers sensitive environments, including observatories and habitats for plants and animals.
Gerard Bowtell-Harris is a technical lighting specialist at Raylinc Lighting and a member of the Illuminating Engineering Society. He designs lighting for roads, pathways, car parks and facades with consulting engineers.
Contact the Raylinc team to check a design for obtrusive light before it goes to tender.