Usually not.
If you’ve been told your electrical service has to be upgraded before a heat pump can go in, there’s a fair chance nobody has measured what your house actually uses. There are two ways to work out whether your existing panel can carry a heat pump. They often disagree, and the wrong one can cost you thousands you didn’t need to spend.
The standard calculation, and the measured one
The first is the standard load calculation, Rule 8-200 of the BC Electrical Code. It adds up what your home could theoretically draw if the range, the dryer, the water heater and a new heat pump all ran flat out at once. It’s deliberately conservative, and on a 100 amp service it very often comes back saying you’re out of room.
The second is the measured demand method, Rule 8-106(8). Rather than assume the worst case, it takes the highest demand your home has actually reached over the most recent twelve months and adds the new equipment to that. Not what could your home draw, but what has it drawn.
Most upgrade quotes we see come out of the first calculation. It isn’t wrong. It just assumes everything in your house runs at once, which it never does.
The formula, and why there’s a 1.25 in it
Here it is in full:
Maximum amps = (highest hourly kWh × 1.25 × 1000) ÷ 240 volts
The highest hourly kWh is the busiest single hour in your last twelve months of BC Hydro data. The 1.25 is there because BC Hydro reports hourly averages, so a short spike inside an hour gets smoothed away and the raw figure understates your real peak. Technical Safety BC set that factor in consultation with BC utilities and other Canadian electrical safety regulators.
Technical Safety BC publishes a worked example on a 200 amp service. A busiest hour of 22.29 kWh, times 1.25, is 27.86 kW. Divided by 240 volts, that’s 116 amps of existing demand, which leaves 84 amps available on the service. That’s their illustration of the arithmetic. It says nothing about your house.
Your new equipment is added to the amps left over, using its MCA, the minimum circuit ampacity printed on the nameplate, which is the continuous load the unit draws. Not its MOP. Maximum overcurrent protection sizes the breaker, and it takes no part in a load calculation.
We’ll determine which method applies to your house
Technical Safety BC sets out which buildings this method can be used on. Broadly, it’s a detached building containing a single dwelling unit, served by a utility that supplies hourly interval data.
A secondary suite on the same meter as the main house does not disqualify the property, and most secondary suites in Metro Vancouver aren’t separately metered. Technical Safety BC routes apartments, townhouses, duplexes, triplexes, quadruplexes, and single homes with a separately metered suite through Rules 8-200(2) and 8-202(3) instead. The disqualifier is the separate meter, not the suite.
New Westminster runs its own municipal electrical utility rather than BC Hydro, so the usage data comes from a different place there.
None of this is yours to work out. Our home comfort advisor confirms it at the visit. And requirements vary between municipalities: Technical Safety BC’s own bulletin, IB-EL 2023-01 Revision 2, says local requirements must be confirmed with the authority having jurisdiction. Nobody should be telling you this is automatic approval, us included.
A 100 amp service, two outdoor units, nine indoor heads
One home we worked on had a 100 amp service already carrying an electric range and an electric dryer. We installed two outdoor units and nine indoor heads on it. Equipment MCAs of 24 and 30 amps, on breakers of 40 and 50.
Most contractors would tell you that can’t be done, and under the standard calculation it couldn’t. Under the measured demand method, it could, and it did.
That job proves the method works, not that your house has the same headroom. We no longer hold that property’s usage data, and your house has its own.
What we do when the panel really is full
Sometimes the measured method says no as well. There are ordinary ways through that:
- A load management device or an interlock, so two large loads can’t run at the same time.
- Switching an electric range to gas, where a gas line already reaches the kitchen. Similar cost to an interlock, and often more practical.
- A service upgrade, if it comes to that.
A service upgrade runs roughly CA$6,000 overhead, or CA$10,000 and up where the service is underground, plus roughly CA$1,400 for BC Hydro’s connection. That work is done by the electrical contractor we bring in. Their charges and BC Hydro’s fee sit outside our starting prices.
Where a service upgrade is done as part of a qualifying heat pump installation, it may be eligible for the CleanBC Electrical Service Upgrade rebate, which as of August 2026 is up to $5,000 on qualifying electrical service upgrades. We assist you with the application, and approved rebates under that program are deducted directly from your invoice, so you pay less upfront rather than waiting for reimbursement. Rebate amounts are subject to eligibility and provincial funding availability. We’ll confirm what you qualify for during your free assessment.
Labelling your panel, and planning for an EV charger
Once an augmented load has been calculated, Rule 2-100(n) requires your service to be labelled with the new figure and the date it was worked out. Our electrician takes care of that.
And the calculation is only as good as the twelve months behind it. Adding an EV charger or a hot tub later means another twelve months of data and another calculation. If either is on your list for the next couple of years, say so at the estimate and we’ll size for both now.
Pulling your BC Hydro usage data
You can do this yourself in a few minutes:
- Log in at bchydro.com.
- Go to My Usage, then Data Export Centre, then Consumption History.
- Choose the Hourly interval and export the last 6 months.
- Repeat for the previous 6 months.
- Email both files to [email protected] with your name and estimate number.
It’s two files because BC Hydro caps a single export at six months. You haven’t done it wrong.
If you’ve been quoted an upgrade
A service upgrade is CA$6,000 overhead, CA$10,000 or more underground, plus roughly CA$1,400 for BC Hydro’s connection. The load calculation that determines whether you need one takes about twenty minutes and costs nothing. If you’ve been quoted an upgrade and nobody asked for your usage data, it’s worth asking why.
Pull the twelve months, and we’ll do the calculation as part of a free assessment. If you’re still working out whether a heat pump suits your home at all, start with how heat pumps handle our winters and what a heat load report actually measures. Or call us at (778) 800-8868.
None of the above replaces a load calculation performed for your specific property by a licensed electrical contractor.