Exterior and security lighting

Good exterior lighting lets people see where they are walking, see who is around them, and be seen by others and by cameras. That depends far more on even coverage, controlled glare and lighting faces than on sheer brightness. Over-bright, glaring lights can make a site less safe, waste energy and annoy the neighbours.

What exterior lighting is for

Exterior lighting has several jobs, and a good design ranks them for each part of the site:

Safe movement: seeing curbs, steps, ice and obstacles on walkways and in parking lots.
Personal security: seeing people approaching early enough to react, and feeling safe walking to a car.
Property security: discouraging intrusion and supporting surveillance by staff, passers-by and cameras.
Wayfinding and identification: entrances, signs and addresses that visitors and emergency services can find.
Appearance: how the building looks at night.

Industry recommended practices, such as those published by the Illuminating Engineering Society, give target light levels and uniformity for parking, walkways and building entrances. Municipal bylaws, energy codes and some site plan approvals add requirements of their own, particularly around light trespass and controls, so check what applies locally.

Uniformity matters more than brightness

The eye adapts to the brightest thing in view. A lot with a few very bright poles and dark gaps between them looks well lit from a distance, but someone standing in a gap is hard to see, and a person walking from a bright patch into a dark one is briefly almost blind. Even, moderate lighting, with no deep shadows, is both safer and cheaper to run than a few powerful fixtures.

Designers express this as a uniformity ratio, comparing the average or maximum light level with the minimum. Recommended practices set limits for different areas. A photometric calculation during design shows the levels across the whole site on a grid, before anything is installed.

Glare, spill and the sky

Glare is light shining directly into people's eyes from a bright source. It reduces what people can see, especially older eyes, and it is the most common complaint from neighbours. Light trespass, or spill, is light that falls beyond the property where it is not wanted. Uplight is light sent above the horizontal, where it does nothing useful and adds to sky glow.

Shielded versus unshielded. A full cutoff fixture puts its light on the ground where it is needed and inside the property line. An unshielded fixture wastes light upward, shines into people's eyes and spills onto the neighbouring property.

The fixes are well established. Use fully shielded, or full cutoff, luminaires that emit no light above the horizontal. Aim fixtures down rather than out. Use house-side shields on poles near property lines. Choose fixtures using their published BUG rating, which describes backlight, uplight and glare, and avoid floodlights tilted up towards the street. Lower colour temperature light, the warmer white sources, is increasingly preferred outdoors for comfort and to reduce sky glow; some municipalities have specific limits.

Lighting the parts of a site

Different areas need different treatment. The site plan below shows the usual pattern for a commercial or institutional building.

Each area gets its own treatment. Entrances get the most light, with faces well lit for people and cameras. The parking lot gets an even grid of poles, the building walls and walkways get wall packs or bollards, and the site edge is kept dim with shielded fixtures so light does not spill.

Entrances

Entrances are the most important area. Light them more than the surroundings, so they are easy to find and anyone at the door is clearly visible. Light faces, not just the ground: vertical light at face height lets staff and cameras identify people, while a single downlight directly overhead casts the face into shadow. Include the address, the intercom and any card reader.

Parking lots

Aim for even coverage across the whole lot, including the far rows where people park after dark. Coordinate pole positions with parking layouts, snow storage and plowing routes, and protect poles from vehicles. Mounting height is a trade-off: taller poles need fewer fixtures but spill more if not well shielded.

Walkways, stairs and ramps

Changes in level must be clearly visible, especially in winter. Bollards and low-level lights are pleasant but can produce glare at eye level for children and people in wheelchairs if poorly chosen; pole or wall lighting is often more even.

Building perimeter and back areas

Loading docks, service doors, waste enclosures and blind corners are where intruders and unsafe conditions tend to be. Wall-mounted fixtures, properly shielded, give even light along the walls without blinding anyone looking towards the building.

Controls

Exterior lights that run at full output from dusk to dawn waste a great deal of energy. Energy codes, where adopted, increasingly require automatic shut-off or reduction, and LED fixtures make dimming straightforward.

Light when it is needed. A photocell or astronomical clock turns the lights on at dusk. After closing they dim, rising to full output when sensors detect someone and dropping back after a timeout, then switch off at dawn.

Common control elements are a photocell or astronomical time clock to switch at dusk and dawn, a schedule to dim after business hours, and motion sensors that bring individual areas back to full output when someone arrives. Dimming rather than switching off keeps a base level for safety and cameras. Our guide to lighting controls covers the options in more detail.

If cameras cover the site, coordinate the control scheme with the camera design: a camera that needs a certain light level to identify faces will not get it from fixtures dimmed to a minimum. See lighting for video surveillance.

A typical case

A medical office building has complaints from staff leaving after evening clinics: the back rows of the parking lot are dark, the main entrance is bright but faces are in shadow, and neighbours complain about a floodlight on the side of the building. A night survey with a light meter confirms deep dark patches between old poles and very bright spots under them. The redesign replaces the old fixtures with shielded LED fixtures on the existing poles where they can be reused, adds two poles at the back of the lot, adds wall-mounted fixtures at face height by the entrance, and removes the floodlight in favour of shielded wall packs. Controls dim the lot after the last clinic closes and raise it on motion. The result is more even, less glaring and cheaper to run.

Maintenance

Walk the site at night a few times a year and note failed, flickering or misaimed fixtures.
Check photocells and time clocks after daylight saving changes and power outages.
Clean lenses, and trim trees that have grown into the light pattern.
Inspect poles, bases and hand holes for vehicle damage and corrosion.
Keep a record of fixture types and drivers so replacements match.

How ehZee can help

We survey existing sites at night, run photometric calculations, and design exterior lighting and controls that balance safety, security, energy use and neighbours. Drawings for permit are sealed by a licensed professional engineer where required, and installation is done by licensed electrical contractors under permit. See our lighting design and controls service.

Common questions

Does more light mean more security?

Not beyond a point. Even, glare-free light that shows faces and lets people see into shadows does more for security than very bright fixtures that create hard shadows and blind anyone looking towards them.

Can we turn exterior lights off overnight?

Some areas can be switched off or dimmed when the site is closed, and energy codes increasingly encourage it. Keep enough light for safety at exits, for cameras and for any staff or security patrols, and check local requirements.

What about emergency lighting outside exits?

Building codes require emergency lighting along exit routes, and the route can continue outside the exit door. See our guide to emergency lighting design.