You are trying to sleep, but a harsh light pours through the curtains — a neighbour’s
floodlight, a badly aimed street light, or a new installation next door. It is annoying,
disrupts sleep, and feels like there is nothing you can do. There is. This unwanted light has a
name — light trespass — and there are real, practical fixes.
What Is Light Trespass?
Light trespass is light falling where it is not wanted or intended — spilling from one
property onto another, through your windows, into your garden. It is one form of light
pollution, and it is almost always caused by a poorly chosen or badly aimed fixture, not by
“too much” light being genuinely needed.
Why It Happens
| Cause | What Is Wrong |
|---|---|
| Unshielded fixture | Light escapes sideways and upward, not just down |
| Wrong aiming | A floodlight tilted up throws light into windows |
| Over-powered light | Far brighter than the task needs |
| Wrong beam angle | Wide flood where a narrow beam was needed |
| Bad placement | Mounted where spill is unavoidable |
Why It Matters (It Is Not Just Annoyance)
- Sleep: light at night disrupts rest and the body clock
- Wasted energy: light going into your window is light the owner is paying
for and wasting - Glare and safety: harsh spill can dazzle drivers and pedestrians
- Neighbour disputes: a common and avoidable source of friction
The Fixes That Actually Work
Shielding. Full-cutoff or shielded fixtures direct light down onto the
target and stop it escaping sideways or up. This alone solves most trespass.
Aiming. A floodlight tilted down instead of out keeps light on the ground,
not in windows.
Right power and beam. Using the correct (often lower) wattage and a narrower
beam puts light only where needed.
Controls. Timers, motion sensors and after-hours dimming mean the light is
bright only when genuinely needed.
If It Is a Neighbour or Street Light
For a neighbour, a polite conversation explaining the spill — and suggesting a shield or
re-aim — usually works, since the fix is cheap and also cuts their bill. For a street light,
report it to your municipality with the pole number; shielding or re-aiming is a standard fix.
Frequently Asked Questions
What is light trespass?
Unwanted light spilling from one property onto another — such as a neighbour’s or street
light shining into your home. It is a form of light pollution.
How do I stop a light shining into my window?
The fixture needs shielding, re-aiming downward, lower power, or a narrower beam — simple,
inexpensive fixes that keep light on its target.
Is light trespass a waste of energy?
Yes — light escaping where it is not needed is energy the owner pays for and wastes.
What can I do about a street light shining in?
Report it to your municipality with the pole number; shielding or re-aiming the fixture is a
standard solution.
Reway supplies shielded, glare-controlled
outdoor lighting that puts light where it belongs — not in your windows. Ask about spill-controlled lighting →
