Ontario doesn’t have one energy code

If you’re specifying lighting for a commercial project in Ottawa, the energy requirements don’t come from a single document, and that’s the first thing worth knowing. They come from Supplementary Standard SB-10, the 2017 energy-efficiency supplement to the Ontario Building Code (OBC), and SB-10 doesn’t contain most of the rules itself. It adopts energy standards by reference, then modifies them.

Under the 2024 edition of the OBC, in force since 1 January 2025, SB-10 Division 3 gives a designer three compliance paths, and the project picks one:

  • ASHRAE 90.1-2013, the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ energy standard for buildings other than low-rise residential, as modified by SB-10 Chapter 2
  • NECB 2015, the National Energy Code of Canada for Buildings, as modified by SB-10 Chapter 3
  • ASHRAE 189.1-2014, Section 7, a green-building standard, with four subsections excluded

Almost every commercial project in Ontario files on one of the first two, and the rest of this article is about those. The 189.1 path carries its own rules and is rarely used here.

Note the editions. Ontario references NECB 2015, not NECB 2020, and ASHRAE 90.1-2013, not a later revision. Newer editions of both exist and are widely quoted online. Neither governs a permit in this province today.

Two designers on the same building can be working to different wattage tables and different control requirements, legitimately, because they chose different paths. So “what does the Ontario code require?” has no answer until somebody says which SB-10 compliance form is being filed.

The wattage tables are Ontario’s own

A project most often picks up a comment here, and it is an easy mistake to walk into.

Lighting power density is the ceiling on connected lighting wattage per unit of floor area, and it is the number your fixture schedule has to land under. Ontario does not use the national figures. SB-10 replaces the tables outright, substituting its own SB-series tables for the equivalents in whichever standard you picked — Division 3, Chapter 3, Article 1.1.1.7 on the NECB path, and Chapter 2, Article 1.1.1.9 on the ASHRAE path.

So a wattage allowance copied from a national NECB summary, a manufacturer’s guide, or a previous project in another province can be the wrong number here, while looking entirely authoritative. The allowance is Ontario’s; the space-type names are inherited. That combination is what makes the error hard to see.

We’ve deliberately not printed allowance figures in this article. They’re edition-specific and table-specific, and a number lifted out of context is the exact failure this section is about. Pull them from the SB tables that match your compliance path.

Two ways to count watts

Both paths let you calculate the allowance one of two ways, and the choice is worth a few minutes rather than a default.

The building area method applies one allowance to the whole building based on its overall type. It is quick, it is easy for a reviewer to check, and it suits a genuinely single-use building.

The space-by-space method assigns an allowance to each space type on the drawings and sums them. It takes more time up front, because every room has to be classified. It usually returns a larger total allowance in any building with a real mix of uses. A space that legitimately needs more light draws its own allowance, instead of being averaged against corridors and storage.

The reflex is to reach for the building area method because it is less work. On a mixed-use plan that reflex often tightens your own budget for nothing. Run both before you commit to one.

The trade-off path has a floor

Both standards offer a trade-off route, where the building demonstrates equivalent performance overall rather than meeting each component requirement on its own.

It doesn’t reach everything. NECB 2015 limits it directly, in Article 4.3.1.2: even where the trade-off path is used, lighting still has to comply with the exit sign and fluorescent lamp ballast requirements, and with the exterior lighting power and exterior lighting control provisions. Four things sit outside the trade-off, and modelling gets you out of none of them. If the design assumed a modelling exercise would absorb them, that assumption fails late.

Code caps watts, the IES answers brightness

These get conflated constantly, and keeping them apart makes the rest of the process easier.

The energy code sets a maximum. It is an upper bound on installed wattage, and it is indifferent to whether the room is any good. It will not tell you a corridor is gloomy or a boardroom table is unevenly lit.

The Illuminating Engineering Society (IES) publishes the recommended practices most lighting designers work to. They aren’t code, and nobody certifies against them. But if the question is how much light a space should actually have, that is where the answer comes from, and the code does not attempt it. We design our photometry to them.

A layout can clear the energy code and still be a room nobody wants to work in. Compliance is a floor to get over, not a description of a good result.

Where the wattage budget gets spent twice

Here is the failure mode worth naming, because it is common and it lands late.

A lighting package clears its allowance on paper. Then the fixture schedule gets value-engineered after the calculation was done, and the substitutions are approved on wattage alone without anyone rerunning the photometrics. The substituted product draws similar watts and delivers a different distribution, so the arithmetic still passes and the rooms come up short. Correcting it means a re-light after the ceiling is closed.

The word to watch in a substitution request is equal. No two products are equal; some are equivalent for the purpose, and that is a judgement somebody has to actually make. An approved substitution needs the calculation rerun, not just the wattage compared.

Four other places projects lose time

Wrong edition, right number. A figure pulled from a national reference rather than the Ontario table. Confirm the path and edition at kickoff, not after a comment.

Controls written up last. The layout gets designed to a wattage target and the control narrative is assembled later, often by whoever is preparing the permit package. Daylight zones get missed this way, because they depend on glazing and orientation that live on the architectural set rather than the electrical one. Our companion article on control requirements covers what the code asks for room by room.

Scope misclassified. Requirements differ between new construction, additions and alterations. Renovation work in an existing building falls under different parts of the OBC. Establish which applies before the requirements are assumed.

No visible calculation. Whichever path is used, the reviewer needs to see the arithmetic and the control narrative, not the conclusion. A fixture schedule on its own invites a comment.

We feed the review, we don’t sign it

We’re a manufacturer’s agent. We don’t certify compliance, we’re not the authority having jurisdiction, and we’re not the engineer of record. What we do on these projects is the work that feeds the review: photometric calculations and lighting layouts, product selection against the wattage budget you’re actually working to, and controls design built into the sequence rather than added to it. Our team holds the Lighting Certified (LC) credential.

We’ll run the calculations before anything is ordered. If you’re working to an allowance and want the layout checked against it while the ceiling is still open, ask us to come and walk the site with you.

Codes move, so check before you file

This reflects the 2024 Ontario Building Code and the 2017 text of Supplementary Standard SB-10. Editions change, and this page carries its own last-updated date. Before relying on any requirement here for a permit application, confirm it against the in-force SB-10 and with your municipal building department.

Common questions

Which energy code applies to commercial lighting in Ontario?

Supplementary Standard SB-10 of the Ontario Building Code, and it works by adopting energy standards by reference and then modifying them. Under the 2024 OBC the project picks one of three paths — ASHRAE 90.1-2013, NECB 2015, or ASHRAE 189.1-2014 Section 7 — and almost every other answer depends on which one is being filed. In practice that is one of the first two. Watch the editions: newer versions of 90.1 and the NECB exist and are quoted everywhere online, and neither governs a permit here.

Can I use the NECB wattage tables in Ontario?

No. SB-10 replaces them with Ontario’s own SB-series tables on both the ASHRAE and the NECB path, while the space-type names stay the same. A figure lifted from a national summary, a manufacturer’s guide or a project in another province looks authoritative and is the wrong number here.

Building area method or space-by-space?

Run both before you commit to one. The building area method is quicker and easier for a reviewer to check, and it suits a genuinely single-use building. Space-by-space usually returns a larger total allowance in anything with a real mix of uses, because a room that legitimately needs more light draws its own allowance instead of being averaged against corridors and storage.

If the lighting meets the energy code, is it any good?

Not necessarily — and they’re not the same question. The code sets a maximum on installed wattage and is indifferent to whether the room works. The IES recommended practices answer the other half: how much light a space should actually have. A layout can clear the energy code and still be a room nobody wants to work in.

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