Low voltage landscape lighting runs on 12V through a transformer stepped down from 120V household power. High voltage (line voltage) runs directly at 120V. For residential landscape lighting in Oakland County, low voltage wins on safety, cost, install flexibility, and code. High voltage still has a place for very bright commercial applications, long cable runs without voltage drop, and specific architectural and flagpole uses. This guide compares both systems on the factors that actually matter.
Quick Answer: Which Should You Pick?
- Residential landscape lighting. Low voltage, almost always.
- HOA or subdivision entry monument. Low voltage for the landscape fixtures, occasionally line voltage for a tall floodlight on the sign.
- Commercial facade wash on a 3 story or larger building. Line voltage, because of the long cable runs and high lumen output.
- Commercial pole-mounted area lights. Line voltage, typically 120V or 277V commercial lighting.
- Sign and flagpole lighting. Either, depending on distance from power and brightness requirement.
Side-by-Side Comparison
| Factor | Low Voltage (12V) | High Voltage (120V) |
|---|---|---|
| NEC code section | Article 411 (limited energy) | Article 410, 300.5 |
| Safety from shock | Inherently safe | Requires GFCI, permit |
| Permit usually required | No (MI residential) | Yes |
| Licensed electrician needed | No for 12V side | Yes |
| Cable burial depth (min) | 6 inches | 18 to 24 inches |
| Typical fixture wattage | 2 to 20W LED | 35 to 150W LED or metal halide |
| Max practical run length | Up to 150 ft per 12-gauge run | 500+ ft |
| Fixture options | Massive residential selection | Commercial selection |
| Modification and expansion | Easy, no electrician | Electrician every time |
| Dim-ability | Multi-tap transformers, smart controllers | Commercial dimmers, more complex |
| Voltage drop across runs | Noticeable, must be designed around | Negligible |
| Installed cost per fixture | $120 to $300 | $250 to $700 |
Why Low Voltage Wins for Residential
The safety case alone settles most residential projects. A 12V landscape lighting system is classified by the National Electrical Code as "inherently limited energy" under article 411. That means even if a kid digs up a buried cable with a garden spade, the worst that happens is the transformer trips. A 120V line voltage cable in the same scenario is a medical emergency.
The cost gap matters too. A 20-fixture low-voltage system installed in Oakland County costs $5,500 to $8,500. Running the same 20 fixtures on 120V would require deeper trenching, conduit, GFCI protection, an electrician on site for the whole install, and permit fees. Easily double.
Finally, flexibility. Want to add a fixture next spring? On a low voltage system, you add a hub, extend the cable, and clip on the fixture. Takes an hour. On a line voltage system, you're hiring the electrician back.
Where High Voltage Still Makes Sense
Three legitimate reasons to use 120V line voltage in landscape lighting:
- Very long cable runs. A run over 150 feet on 12-gauge low voltage cable starts to show noticeable voltage drop. Beyond 200 feet you're heading into 10-gauge or 8-gauge, which gets expensive and hard to work with. Line voltage runs 500+ feet without issue.
- Very high lumen applications. A 3 story office facade needs 150W fixtures to look right. That's 12 amps at 12V, which requires heavy cable. At 120V it's 1.25 amps.
- Integration with building electrical. Commercial buildings often have 120V or 277V exterior outlets already run. Tying landscape fixtures into existing circuits can be simpler than setting up a transformer bay.
Hybrid Systems Are Real
Most serious commercial projects in Oakland County use both. The transformer is 120V fed. The bulk of the landscape fixtures are 12V because they're safer and cheaper. A few specific fixtures (a tall sign floodlight, a building-mounted wall pack) are 120V line voltage because nothing else makes sense. Good design is knowing where each system belongs, not treating it as an either-or.
Cite: NEC article 411
The National Electrical Code (NFPA 70) article 411 governs lighting systems operating at 30V or less. This is the section that defines low voltage landscape lighting as inherently limited energy and sets the 6 inch cable burial minimum. Source: NFPA, NEC 2023 edition.
What We Recommend
For Oakland County residential projects: 100 percent low voltage in nearly every case. For commercial projects under $25,000: typically 100 percent low voltage. For commercial projects above that, or any project with a fixture over 40W or a cable run over 150 feet, we evaluate hybrid.
Ready to scope your project? See our residential outdoor lighting or commercial landscape lighting service pages, or request a custom design plan that specs the right voltage system for your situation.