Electrification Load Planning in Ontario (2026): Will a Heat Pump, Induction, Heat Pump Water Heater, EV and Hot Tub Fit on 100 or 200 A

The numbers

October 2026, before HST. Rough-in budgets are the middle of each range. The cheapest wire is the one run before the drywall: a 4 dollar wire before drywall is a 400 dollar wire after it.

The Rule 8-200 Arithmetic in Plain Words

The code does not add up every breaker. It adds a basic load for the size of the house, then the big appliances, each discounted for how often it really runs:

• Basic load: 5,000 W for the first 90 m2 of living area, plus 1,000 W for each additional 90 m2 or part of it. Living area is 100 percent of the floors at and above ground plus 75 percent of the basement area more than 1.8 m high.
• Electric space heat: the first 10 kW at 100 percent, the rest at 75 percent.
• Air conditioning or heat pump: 100 percent. Where heating and cooling are interlocked so they cannot run together, only the larger counts.
• Range: 6,000 W, plus 40 percent of any rating over 12 kW.
• Tankless water heaters, pool, hot tub and spa heaters: 100 percent.
• EV charger: 100 percent, unless an energy management system limits it under Rule 8-106.
• Everything else over 1,500 W (dryer, storage water heater): 25 percent when there is a range. Without a range, 100 percent of those loads up to 6,000 W plus 25 percent of the rest.
• Floor: never less than 24,000 W, which is 100 A, for a house of 80 m2 or more not counting the basement. Divide watts by 240 V for amps.

One House, Worked Step by Step

A 2,000 sq ft two-storey, 1,000 sq ft a floor, over a 1,000 sq ft basement with full head height. All electric: a 3 ton cold-climate heat pump (we used 4,800 W as an example rating; your nameplate decides) with 15 kW of electric backup heat that can run with it, an 11.6 kW induction range, a heat pump water heater with 4,500 W elements, a 5,000 W dryer, and an EV charger set to 40 A on a 50 A circuit.

1. Convert the area. At 10.764 sq ft to the m2: 2,000 sq ft is 185.80 m2; the 1,000 sq ft basement is 92.90 m2, and 75 percent of that is 69.68 m2. Living area 185.80 + 69.68 = 255.48 m2.
2. Basic load. First 90 m2: 5,000 W. That leaves 165.48 m2, which is one full 90 m2 and part of a second, so two more steps: 2,000 W. Basic load 7,000 W.
3. Backup heat. 10,000 W at 100 percent, plus the other 5,000 W at 75 percent, 3,750 W. Total 13,750 W.
4. Heat pump. 4,800 W at 100 percent. The backup runs alongside it in cold weather, so both count.
5. Range. 11.6 kW is under 12 kW, so 6,000 W. Induction or coil, same number.
6. EV charger. 40 A x 240 V = 9,600 W at 100 percent, no load manager.
7. Dryer and water heater. 5,000 + 4,500 = 9,500 W, at 25 percent because there is a range: 2,375 W.
8. Add it up. 7,000 + 13,750 + 4,800 + 6,000 + 9,600 + 2,375 = 43,525 W. Divided by 240 V, 181.4 A.

So it fits on 200 A, with 18.6 A to spare on paper. That is a full parking lot with one stall left, and a hot tub is a pickup truck. If the controls lock the compressor out whenever the backup heat runs, the code counts only the larger of the two, and your electrician and ESA make that call; I counted both, the cautious way.

The Same House in ICF, and What a Hot Tub Does

For the example we assumed the same house in ICF loses about half the heat, so it wants a 2 ton heat pump (we used 3,500 W) and 5 kW of backup, the size of a small electric boiler. Every other line stays the same. Then add a 5.5 kW hot tub heater at 100 percent, and then a load manager on the charger, which under Rule 8-106 takes the 9,600 W out.

Example ratings, not your nameplates. Your licensed electrical contractor does the real calculation, and the 2024 code requires the maximum residential load to be labelled.

The last row is a curiosity, not advice. A new all-electric house built on 100 A has no room left for anything you add later. What the table shows is that the heat loss is the swing line. The frame house needs a load manager to keep a hot tub on 200 A; the ICF house carries the hot tub and the charger with about 38 A to spare. That is the same reason my ICF showhome in Tiny Township costs about $100 a month to heat in the coldest part of winter. The ICFhome.ca houses are built this way; the ICF vs stick-built page has the rest.

Planning Rules That Save a Service Upgrade

1. Get the heat loss before anyone sizes the backup heat. Backup heat is the biggest variable in the calculation, and it should come from a room-by-room heat loss, not a guess. OntarioHeatLoss.ca does the CSA F280 report; the cold-climate heat pump page explains why a good one needs less backup.
2. Do not blame the induction range. Under 12 kW it counts 6,000 W, the same as the coil range it replaces.
3. A heat pump water heater counts like a tank. It is a storage heater at 25 percent; a tankless electric heater is the one that counts at 100 percent and can sink a service.
4. The charger is the line you can manage. A load manager, or a lower charging current, is cheaper than an upgrade. The EV on 100 amps page has the options.
5. On an existing house, measured demand can count. Rule 8-106 lets an existing service be evaluated with measured actual demand data when load is added. Only a licensed electrical contractor and ESA make that call.
6. Plan the order. If an upgrade is coming anyway, do it before the heat pump, not after; the panel upgrade cost page prices it and the subpanel page explains why more breaker spaces do not help.

Questions people ask

Sources and further reading

• ESA Bulletin 8-3-15: demand factors: ESA’s worked load calculation for a house with air conditioning, a range and a Level 2 charger.
• ESA Bulletin 86-1-7: electric vehicle charging systems: how an EV charger is counted in the load calculation and how an energy management system changes it.
• Ontario Electrical Safety Code: ESA on the 2024 (29th) edition in force since May 1, 2025, and what changed for houses, EV loads and energy storage.