Heated driveways have crossed from niche to mainstream on the high-end residential builds in Burlington, Oakville, and Ancaster — and we get the electrical-quote call on at least one a month through the fall. The driveway itself is a paving and waterproofing job. The electrical side is a substantial scope that homeowners and even some general contractors routinely underestimate. Here is what an electric snow-melt driveway actually demands from the panel.
The load math: 15 watts per square foot
The industry standard for electric snow-melt resistance cable in Ontario is 12–15 W per square foot of treated surface. The math is unforgiving:
- A 600 sq ft driveway pad (a small two-car driveway): 9,000 W → 37.5 A at 240V
- A 1,000 sq ft driveway: 15,000 W → 62.5 A at 240V
- A 1,500 sq ft driveway plus walkway: 22,500 W → 93.75 A at 240V
- A 2,500 sq ft driveway plus walkway plus pool deck: 37,500 W → 156 A at 240V
For a typical Burlington estate driveway approaching 2,000 sq ft, the heating load alone is over 100 A continuous. This is not something you bolt onto an existing 200A house service.
The service-size conversation
An electric snow-melt driveway above ~800 sq ft almost always triggers a service upgrade or a dedicated additional service. The options:
- Upgrade to 400A service. The standard answer for homes that were on 200A and are adding snow-melt. 400A residential is increasingly common in Burlington and Oakville new builds and is well within our standard scope. ESA permit, utility coordination with Burlington Hydro, Alectra, or Oakville Hydro, meter base upgrade.
- Dedicated secondary service. A separate utility drop for the heating system only — typically a 100A or 200A service for the snow-melt and any related exterior loads (pool, landscape lighting, garage HVAC). Cleaner on the panelboard side; more expensive on the utility-coordination side. We do this on larger estates where the snow-melt system is more or less its own building.
- Reduce the scope. Heat the wheel tracks only instead of the entire pad. Cuts the load by 40–60%. Aesthetically less perfect but the math gets easier and the operating cost drops with it.
Dedicated subpanel for the snow-melt system
Regardless of the service approach, the snow-melt system gets its own dedicated subpanel. The reasons:
- The load is large enough that putting it on the main panel pushes everything else off
- The subpanel is sized to the snow-melt design (often 100A or larger) and houses the contactor that switches the heating zones
- Service disconnection is local — when the cement crew or paving crew needs the cable de-energized for any work, they kill the snow-melt subpanel without touching the rest of the house
- Fault diagnosis is cleaner — a heating zone that fails an insulation test shows up at its own breaker, not buried in the main panel
The subpanel typically lives in the garage or a mechanical room near the driveway. Feeder from the main service, contactor switched by the controller, individual breakers for each heating zone.
Zoning: splitting a large driveway into manageable zones
A 2,000 sq ft driveway is rarely wired as a single 100A zone. It is broken into multiple zones for several reasons:
- Manageable breaker sizes — five 20A zones is easier to fuse and protect than one 100A zone
- Independent control — the entry portion can run while the back portion stays off, for selective melting
- Cable-length manageable — heating cable kits have maximum run lengths; zoning lets each zone sit inside the manufacturer's limit
- Fault isolation — a single damaged cable run takes out only its zone
The controller: the brains of the system
The heating cable itself is dumb. The controller is what makes the system economical. Three tiers:
- Manual. A switch in the house. Owner decides when to energize. Simple, cheap, and a near-guaranteed way to spend money — owners either turn it on too early ("might snow tonight") or forget to turn it off.
- Aerial sensor + slab sensor. Industry standard. An aerial sensor measures outdoor air temperature and moisture (snow detection). A slab sensor in the driveway pad measures pavement temperature. The controller energizes the heating only when air is cold AND there is moisture (snow falling or accumulating) AND the slab is below a setpoint. Real savings: the system runs only when needed. Brands: Tekmar 654, Heatcomm SMC-200, Warmup snow-melt controllers.
- Networked smart controller. Adds remote access, weather-API integration, and energy-use logging. Justifiable on larger systems where the operating cost makes the controller cost trivial.
Electric vs hydronic: the trade-off
The competing technology is hydronic snow-melt — antifreeze-circulating tubing in the pad, fed from a high-efficiency boiler or heat pump. The comparison:
- Electric upside: Simpler install, no boiler room, fast response time, controls are mature, electrical can be done on a one-trip schedule.
- Electric downside: Massive electrical load, higher operating cost per BTU than gas-fired hydronic, requires service capacity many homes do not have.
- Hydronic upside: Lower operating cost if you have natural gas, can be paired with a high-efficiency condensing boiler that also supplies domestic hot water or radiant floors, modest electrical impact (just pump and controls).
- Hydronic downside: Significantly larger up-front cost, needs a mechanical room, longer install schedule, slower response time, more failure points (boiler, pump, glycol charge).
For a Hamilton or Burlington property already running a hydronic radiant floor system in the basement, adding a snow-melt zone on the existing boiler is often the better answer. For a new build with no other hydronic load, electric is simpler and faster. We will walk both options if you are considering it from scratch.
Cable types and what we install
Resistance heating cable for snow-melt comes in mat and spool form. We install mostly self-spaced cable on a spool, laid out in serpentine pattern by the installer before the pad is poured. Brands we trust: WarmlyYours SnowMelt, Easyheat WarmTiles SR-Series snow-melt, Raychem T2Red snow-melt, Heatline HSL-2. The cable connects to a cold lead that exits the pad through a sleeve, runs to the subpanel, and terminates on a contactor with manufacturer-spec termination kits.
Operating cost: the conversation owners need to have
A 1,000 sq ft driveway at 15 W/sq ft running for the duration of a single Hamilton snow event (say, 4 hours of active heating plus 6 hours of after-storm hold) draws around 150 kWh. At Ontario time-of-use rates that is a meaningful per-event number, and a winter has 15–25 events. Annual operating cost on a 1,000 sq ft pad is real — meaningfully more than a hydronic system on natural gas. Owners going in with their eyes open about that are happy with the system. Owners who were told it would be "a few dollars a snowfall" are not.
When to call us
If you have a snow-melt driveway in design or you are getting paving quotes that mention heated cable, we will quote the electrical side standalone. Most installs need a service upgrade first; we do both together as a single coordinated scope. Request a snow-melt electrical quote and send a site plan if you have one.