Guides
Low-Voltage Patio Lighting: A Layout That Avoids Glare
A low voltage patio lighting layout that avoids glare starts with fixture height, beam spread and one run of 12-gauge cable. Here is the sequence.
What to take away
- Glare is the sight of a lamp or its reflection, not the amount of light. Shield every source and aim it down or across a surface.
- A 12-volt circuit loses voltage with distance. Keep the last lamp near 11.6 volts, or move the transformer closer to the load.
- Path lights sit below eye level, at 18 to 24 inches. Step fixtures recess into the riser with a louver over the lens.
- No US model code requires step lighting on a private patio. The electrical rules govern the outlet, the transformer and the trench.
- Read voltage at the last fixture before you backfill. That one number catches most bad layouts.
Where the glare comes from
A seated eye adapts to the brightest thing in view. A three-watt lamp seen directly at night reads as harsher than a shielded lamp ten times brighter. Glare reaches the eye two ways: the bare source, and the source reflected off a glass table, a wet paver or a window.
Design around sightlines rather than fixtures. Sit where people will sit, then look across the patio. Anything inside that cone needs a shield, a lower mount or a different aim.
On a small site every placement error shows up faster, which is the argument in Tight patio sites.
Height, beam and aim
| Fixture | Mount height | Beam spread | Aim and shield |
|---|---|---|---|
| Path and bed | 18 to 24 in | 20 to 30 degrees | Down, with a cap over the lens |
| Step light | In the riser, 1 to 2 in above the tread | 60 to 90 degrees | Across the tread, louvered |
| Post or wall | 5 to 6 ft | 40 to 60 degrees | Downward only, no uplight at the seats |
| Tree uplight | At grade | 10 to 20 degrees | Up the trunk, outside the seated view |
| String lights | 8 to 10 ft | Bare lamp | Above and behind the seating |
Narrow beams cut glare because light lands on a surface instead of an eye. Step lights need wide, even wash across the tread, so the shield does work a beam cannot. The same glare control in outdoor lighting drives commercial walkway design.
The 12-volt circuit and voltage drop
Outdoor lighting answers to two sets of rules. The low-voltage side, at 30 volts or less, falls under Article 411 of NFPA 70, the National Electrical Code, which covers the wiring method, the transformer and the trench. The 120-volt side is stricter: outdoor receptacles need GFCI protection, and Section 210.52(E) requires an outlet at grade at the front and back of a dwelling.
On the 12-volt side, distance is the design problem. A drop near three percent is a normal target, which keeps the last lamp at about 11.6 volts. As a working rule, 12-gauge cable carries a full loop to roughly 100 feet. Longer runs want 10-gauge wire or a second transformer closer to the load.
Sequence for a layout that works
- Sit in the chairs and draw the sightlines on a plan.
- Place fixtures, then move any that land inside those sightlines.
- Set the transformer 10 to 15 feet from the first fixture, on a GFCI outlet.
- Run each zone as a home run instead of daisy-chaining the whole yard.
- Connect the farthest lamp first and read voltage there before you close the trench.
Step two carries the most weight, and patio design regrets lists the complaints that surface a season or two later.
Checks before you bury anything
- Last fixture reads 11 volts or higher with every lamp lit.
- Each fixture has a shield, cap or louver between the lens and a seated eye.
- Cable sits below the burial depth your wiring method requires.
- Transformer load stays under 80 percent of its rating.
- Timer and photocell set, and the transformer plugged into a GFCI receptacle.
Example layout for a 20 by 16 foot patio
Take a patio 20 feet wide and 16 feet deep with one 7-inch step down to the lawn and seating along the house wall. Two zones cover it. Zone one holds nine 2-watt path lights along the far edge, a run of 84 feet on 12-gauge cable. Zone two feeds four louvered step lights and two 3-watt wall washers.
The load lands near 32 watts, so a 60-watt transformer leaves headroom. No zone draws more than 1.5 amps, which holds voltage drop under half a volt at the end of the path run. Keep the wall washers aimed at the brick rather than out into the yard. A screened roof changes the picture too: fixtures can hang from the framing, and Screen In a Porch covers that structure.
When to hand it to an electrician
Stop and call a licensed electrician when the job needs a new 120-volt branch circuit, any work inside the panel, or a receptacle within 5 feet of a pool or spa. Hand over the trench if it crosses a gas line, a sewer or an irrigation main you cannot trace. A layout on paper is a weekend. A new circuit is not.
Common questions
Do low-voltage patio lights need a permit? Rarely, when the transformer plugs into an existing outdoor receptacle. A new branch circuit is where cities take an interest, and that call belongs to your jurisdiction.
How far apart should path lights sit? Six to 8 feet gives an even wash with 20 to 30 degree beams. Wider spacing saves fixtures but leaves dark gaps that read as trip hazards.
Can low-voltage cable lie on the surface? Only where the cable is listed for it and the run stays under mulch. Bare cable across a walkway is a cutting and tripping hazard, and few inspectors accept it.
Why do the far lights look dim? Voltage drop across a long loop. Move the transformer closer, split the zone, or step up to 10-gauge cable. If the loop cannot be shortened, the questions in different contractor questions separate a real diagnosis from a sales pitch.
