What the form is
The City of Calgary load calculation form is a one-page summary that shows the inspector how you arrived at the total demand on a dwelling's electrical service, and that the service you've installed — breaker and conductors — is big enough to carry it. It is not a design document and it is not a permit application. It's the arithmetic, on paper, in the City's format.
You'll be asked for one on essentially any job that materially changes the demand on a service:
- Secondary suites — the most common trigger by a wide margin
- Laneway and backyard suites
- EV charger installations
- Hot tubs and spas
- Service upgrades of any size
Where to get it — and why a fresh copy matters
Download it from the City directly. The secondary suite pages on calgary.ca are the starting point, and the load calculation PDF is hosted there.
Do not reuse the PDF sitting in your downloads folder from last year's job. The City revises its forms, and submitting a superseded version is one of the easiest ways to get bounced before anyone even looks at your numbers. Thirty seconds of downloading saves a week of back-and-forth.
When and how it gets submitted
The completed form goes to the City's electrical inspection group by email, before the electrical rough-in inspection. That timing matters more than people realise. If you wait until the inspector is standing in the basement, any question about the calculation stops the job with the walls open. Send it as soon as the design is settled and the loads are known.
Section by section
Project, address and permit
The top of the form is identification: the site address, the property details, and the electrical permit (EP) number issued for the job. That EP number is what ties the calculation to a file the inspector can actually find. Submitting without it is the paperwork equivalent of mailing a letter with no address.
Dwelling unit identification
You identify what you're calculating for — single family dwelling, secondary suite, or laneway/backyard suite. On a suite project you are describing the whole property's service, with the suite as part of it, not the suite in isolation.
Living area in square metres
This is where most homeowner-completed forms go wrong. The form works in square metres. Entering 1,200 because that's the number on the real estate listing produces a calculated load that is roughly ten times too large, and it is immediately obvious to anyone reading it. Divide square feet by 10.764.
Basic load from floor area
The area figure drives the basic load block under CEC Rule 8-200:
| Living area | Basic load |
|---|---|
| First 90 m² | 5,000 W |
| Each additional 90 m², or portion of it | 1,000 W |
Note the "or portion" — a 95 m² dwelling picks up the full additional 1,000 W, not a prorated slice of it. This is the floor the rest of the form builds on.
Heating and air conditioning
Rows for electric space heating and for air conditioning, with provision for an interlock between them. If heating and cooling are interlocked so they cannot operate at the same time, only the larger of the two counts. If they are not interlocked, both count. Claiming the interlock allowance without actually installing the interlock is a claim the inspector can check, and does.
Range
An electric range gets its own row. On a suite project there are frequently two ranges, and the suite's is the one that gets forgotten. If the suite is going in with a gas range, say so — it changes the answer meaningfully.
Water heating
Conventional electric tank water heaters are straightforward. Tankless electric units are the single most-missed load we see, and they are enormous — often larger than everything else in the suite combined. If there's a tankless unit anywhere in the project, it belongs on this form.
Hot tub
Full nameplate rating. Hot tubs get added late in projects, after the calculation was already done and filed. If one is planned at all, put it on the form now rather than redoing the exercise next spring.
EV charging
Electric vehicle supply equipment is counted at its full rating with no diversity allowance — unless a load management system (EVEMS) is installed, which reduces its contribution. On tight services this row alone decides whether you need a service upgrade.
Additional loads
The catch-all for everything else fixed and significant: heat pumps, garage heaters, workshop equipment, air handlers, well pumps. If it's hard-wired and substantial, it goes here.
Totals, breaker and conductors
The bottom of the form is the payoff: total calculated watts, converted to amps, followed by the main breaker (service overcurrent protection) size and the service conductor size and type. These three have to be consistent with each other and with the service actually installed. And regardless of what the demand calculation says, the Code sets a floor:
100 A where the floor area excluding basement is 80 m² or more. 60 A where it is less than 80 m². Most Calgary houses are comfortably in the first category, so 100 A is the realistic starting point — not a target to aim for.
Let the form fill itself in
Enter your loads once and the free calculator produces both the full CEC 8-200 breakdown and a completed Calgary form PDF from the same data — so the paperwork and the math can't disagree with each other.
Run the free calculator →Why forms get sent back
Six reasons account for nearly all of them:
| Problem | What happened |
|---|---|
| Stale form version | An old PDF reused from a previous job instead of a fresh download. |
| Square feet in a square metre field | The area entered without converting. Everything downstream is wrong. |
| Missing the suite's range | Only the main dwelling's appliances captured. |
| Double-counting interlocked heat and A/C | Both entered in full when only the larger should count — or the reverse, claiming the interlock without one. |
| Forgotten tankless water heater | The biggest single omission, and it rarely survives review. |
| Math that doesn't match the drawings | The panel schedule and the calculation describe two different projects. |
That last one is worth dwelling on. The inspector has your drawings. If the form shows one range and the plans show two kitchens, that discrepancy gets noticed. Keep the two documents in step.
If the service size has to change
If the calculation pushes you from 60 A to 100 A, or 100 A to 200 A, you are no longer dealing with the City alone. ENMAX becomes involved for the service change itself, and that is a separate process with its own timeline and coordination. Discover this at the calculation stage, not at rough-in — the lead time on a service change is the thing most likely to stall a suite project outright.
Frequently asked questions
Where do I get the City of Calgary load calculation form?
Download it directly from calgary.ca — the secondary suite pages on the City site host the current load calculation PDF. Always pull a fresh copy for each project rather than reusing one saved on your desktop, because the City revises its forms periodically and a superseded version is an easy reason to be sent back.
When does the load calculation form have to be submitted?
It is emailed to the City's electrical inspection group before the electrical rough-in inspection. Leaving it until the inspector is already booked is the most common scheduling mistake on suite projects — get it in early so any questions are resolved before walls are being closed.
Which permits need a load calculation in Calgary?
Anything that meaningfully changes the demand on the service. In practice that means secondary suites, laneway and backyard suites, EV charger installations, hot tubs, and any service upgrade. If you are adding a large fixed load or a second dwelling unit, expect to submit one.
What is the minimum service size for a house with a suite?
Under the Code, minimum service ampacity is 100 A where the floor area excluding basement is 80 m² or more, and 60 A where it is less than 80 m². Most Calgary houses land in the first category, so 100 A is the practical floor — and the calculated demand may require more. See can a 100 A service handle a secondary suite? for the full picture.
Want it checked before it goes in?
A completed form reviewed by a master electrician before submission costs you nothing in delay and can save a rough-in inspection. Send it over.
Get it signed off →General information for planning purposes only — not a code ruling or a substitute for a permit submission. Confirm current form versions and submission requirements at calgary.ca. Final acceptance rests with the authority having jurisdiction.