Commercial & HOA
Load Planning for Multi-Building Commercial Displays
October 8, 2026
A breaker that trips at 4:50 p.m. on a Friday in December is almost never a bulb problem. It's an amperage problem that was baked in back in October, when somebody ran the lodge roofline, the porte-cochère, the monument sign, and four wrapped spruce off the same exterior receptacle because that's the outlet that was there.
On multi-building properties around Summit County — a lodge with detached guest cabins in Keystone, a strip of retail bays in Dillon, an HOA with a clubhouse and three entry monuments in Silverthorne — load planning is the difference between a display that runs all season and one that needs a service call every cold snap. It's worth doing before anyone climbs a ladder.
Exterior circuits on mountain commercial buildings are rarely what you'd assume
Most commercial buildings up here weren't wired with a December lighting load in mind. The exterior receptacles that exist are usually there for maintenance equipment, a snowmelt controller, or a vending machine — and they're frequently sharing a 20-amp circuit with something you can't see from outside.
That matters because a holiday display isn't a momentary draw. It's continuous, 14 hours a day, for eight or nine weeks. The code convention for continuous loads is to stay at or below 80% of a circuit's rating. On a 20-amp, 120-volt circuit, that's 16 amps of usable headroom, or roughly 1,920 watts — and you don't get all of it, because whatever the circuit was originally feeding is still feeding.
Plenty of older properties in Frisco and Dillon have GFCI receptacles that are already marginal. Add a winter's worth of moisture, blowing snow, and a cord cap that collects ice, and the GFCI starts nuisance-tripping. The display looks broken. The wiring is fine. The plan was wrong.
What a multi-building property actually draws
LED changed the math, but it didn't eliminate it. Commercial-grade LED C9s and mini lights draw a fraction of what incandescent did, which tempts people into running enormous runs off one feed. The limit you hit first usually isn't total wattage — it's the manufacturer's maximum end-to-end connection count per run, and after that, voltage drop.
Voltage drop is the quiet one. Push a run too long, and the far end of the string dims, shifts color, or flickers in a way nobody can diagnose from the ground. On a 200-foot commercial roofline wrapping two sides of a building, that's a real constraint, not a theoretical one.
Then there's the rest of the display. Inflatables and animated motifs have motors. Transformers for low-voltage landscape elements have inrush current. Heated or snow-resistant elements, if a property uses them, draw more than everything else combined. A property manager who adds a lit archway in year two without recalculating has quietly moved the whole display past its margin.
Why a dedicated circuit or subpanel pays for itself on a campus property
Here's the practical case for having an electrician add dedicated exterior circuits — or, on a larger campus, a small subpanel with a timer or photocell — before the lighting season:
- Isolation. When the display is on its own circuits, a fault in the lighting doesn't take down a walkway light, a security camera, or a heat tape run.
- Control in one place. One timer at one panel beats a dozen outdoor timers scattered across three buildings, each one with its own battery backup to fail at 10 below.
- Headroom for next season. HOA boards add to displays. They almost never subtract. Building in spare capacity now means next year's addition is a design conversation, not an electrical project in November.
- Fewer winter service calls. A dark section on a Breckenridge commercial frontage during a holiday weekend is a visible problem. Properly loaded circuits are the single biggest reason displays stay lit.
Summit Mountain Lights doesn't do electrical work — we're installers, and panel work belongs with a licensed electrician. What we do is tell you, before you call one, exactly how many amps your proposed display will pull, where the feeds need to land, and what to ask for.
Elevation and weather make the electrical plan a physical plan too
Where the power lands is as important as how much of it there is. At 9,000-plus feet, a connection sitting on a roof deck will spend January under accumulation. A connection at a Dillon property catching wind off the reservoir will get worked loose if it isn't secured and oriented so water drains away from it rather than into it.
We plan feeds to come off protected soffits and covered entries where possible, keep connections up off grade and out of the snow shed line below a standing-seam roof, and secure cord runs at tighter intervals on exposed elevations than we would on a sheltered courtyard. A roof avalanche off a metal roof will take a cord run with it if that run is in the path — and on a commercial building, that's a tenant entrance below.
What to do in September and October, not November
The install window up here is short. Crews lose usable daylight fast through November, and the first heavy snow sets the real deadline. Electrical lead time is the piece that blows up schedules, because an electrician's December is as full as ours.
If you manage a multi-building property, do this now:
- Find the panel schedules for each building and note which exterior circuits exist and what else is on them.
- Walk the property and mark every place you want light, including anything a board or ownership group has been asking about.
- Get the display designed and the load calculated before you call an electrician, so the scope is a number, not a guess.
- Book the electrical work for October. That leaves November for installation, which is where it belongs.
Tell us the property, the buildings, and roughly what you want lit, and we'll walk the site, design the display, and hand you an amperage plan you can take straight to your electrician. Start with a free estimate.