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SB-12 Explained: The Energy Rules Your Ontario House Has to Meet, in Plain English
Permits and code Energy From a builder
SB-12 Explained: The Energy Rules Your Ontario House Has to Meet
Every new house in Ontario has to show the building department how it meets the energy efficiency requirements of the Building Code. The document that does that is SB-12, and the form that proves it goes in with your permit. Here is what it asks for and how the choices affect your house.
Short version: SB-12 is the Supplementary Standard to the Ontario Building Code that sets energy efficiency requirements for houses. You comply either by picking a prescriptive package (a table of minimum insulation, window and mechanical values that go together) or by the performance path (an energy model showing your design uses no more energy than the reference house). Your designer picks the route and files the energy design summary with the permit. ICF walls meet or beat the above-grade wall requirement in every package; the attic, windows, basement slab and mechanical still have to hit their own numbers.
Where SB-12 sits in the Code
Part 9 of the Ontario Building Code says a house has to meet energy efficiency requirements, and points to Supplementary Standard SB-12 for the details. SB-12 is published by the province and updated with the Code; the 2024 Code edition in force since January 2025 carries its own version. It applies to new houses and to additions above a certain size, and it is enforced through the energy design summary form in the permit application and through the insulation inspection on site. The 2024 Ontario Building Code and the Building Code guide on this site give the wider picture.
The two ways to comply
Prescriptive packages. SB-12 publishes tables of packages, each a set of minimum values that go together: attic insulation, above-grade wall, basement wall, slab, windows (U-value or energy rating), heating equipment efficiency, HRV efficiency, and so on. You pick a package that suits your heating fuel and your design, build to every line of it, and you comply. Trade-offs are built into the tables: a package with triple-pane windows may allow a lower wall value than one with double-pane. Most houses in Ontario go this route because it is simple to show and simple to inspect.
Performance path. An energy modeller (often an EnerGuide advisor) models your actual design and shows that its annual energy use is no greater than a reference house built to a prescriptive package. This lets you trade: more glass on the south side against a better attic, say. It costs a modelling fee, and it is the route for houses with a lot of glass, unusual shapes, or a target like net zero ready. NRCan’s EnerGuide evaluations are the same tool used for the rating label.
What it means for the parts of your house
| Element | What SB-12 looks at | What it means in practice |
|---|---|---|
| Attic | Nominal R-value of the insulation | Blown cellulose or fibreglass to roughly R-60 in most packages; cheap to exceed |
| Above-grade walls | Effective R-value of the assembly, counting studs | A 2×6 wall with batts needs exterior continuous insulation in many packages; ICF meets the requirement with the foam alone |
| Basement walls | R-value to within a set distance of the slab, or full height | Insulated full height in most packages; ICF basements comply by construction |
| Slab | Under-slab insulation where heated, and at the edges | Required under a heated slab such as radiant; worth doing regardless |
| Windows and doors | U-value or Energy Rating, by package | Double-pane low-e argon is the floor; triple-pane buys trade-offs elsewhere |
| Heating equipment | Minimum AFUE or HSPF by fuel | Condensing gas, or a heat pump that meets the package |
| Ventilation | HRV or ERV with a minimum sensible recovery efficiency | An HRV is effectively required in every new house |
| Hot water | Efficiency minimum by type | Condensing or heat pump water heaters score well |
| Air tightness | Required in some packages, credited in the performance path | A blower door test proves it; ICF houses test very tight |
Insulation R-value explained covers the nominal-versus-effective distinction that trips people up on the wall line, and ICF R-value explains why ICF walls comply without an extra layer.
How it gets checked
Twice. On paper, the energy design summary with your permit application lists the package or the modelled result and the values for every element; the plans examiner checks the drawings against it. On site, the insulation and vapour barrier inspection checks that what went into the walls and attic matches the form, and the mechanical inspection checks the equipment. Swap the windows for a cheaper line after the permit and the inspector is entitled to ask where the compliance went. The inspections guide describes the visit.
Where people get it wrong
- Choosing a package before choosing the heating system. The packages are organized by fuel and system; pick the system first.
- Treating the wall R-value as nominal. The Code wants the effective value of the assembly, which is why a stud wall usually needs exterior foam.
- Forgetting the slab. Radiant floors need under-slab insulation, and the compliance form will ask for it.
- Changing windows after the permit without re-checking the package.
- Skipping the HRV commissioning report; many inspectors ask for the balancing report at final.
Beyond the minimum
SB-12 is a floor, and it is a reasonable one. Going past it pays back in comfort and bills, in this order: air sealing, windows, walls, mechanical sized from a real heat loss. An ICF house with triple-pane windows and a correctly sized system sits well above the Code and is what we build by default; air sealing an Ontario home explains why the air barrier is where the cheap gains are. If you want a label for it, the EnerGuide rating and the net zero ready standard are the two most people ask about.
Related guides on this site
Sources and further reading
Questions people ask
What is SB-12 in the Ontario Building Code?
Supplementary Standard SB-12, Energy Efficiency for Housing. It sets the minimum insulation, window, mechanical and ventilation requirements for new houses, through prescriptive packages or a performance path, and is enforced through the energy design summary filed with the building permit.
What is the difference between the prescriptive and performance paths?
Prescriptive means building to every value in one of SB-12's published packages. Performance means an energy model shows your design uses no more energy than a reference house, which lets you trade one element against another.
Does an ICF house meet SB-12?
The ICF wall meets or exceeds the above-grade and basement wall requirements in every package on its own. The attic, windows, slab, heating and ventilation still have to meet their own lines in the package.
Do I need triple-pane windows in Ontario?
Not by Code in most packages; double-pane low-e argon meets the minimum. Triple-pane buys trade-offs elsewhere in the package and real comfort on north faces and large glass.
Got a code question this page did not answer?
Ask it in plain English and the OBC Code Navigator answers with the Part, Section and Article from the Ontario Building Code. Two questions free. Your municipality and inspector still have the final word.
Reviewed and updated October 2026. Costs are Ontario ranges, not quotes; code references are to the Ontario Building Code in force at that date.
