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Canada energy code: ER, U-factor and the cold case
The Canada energy code line is a provincial line: the national model code sets the envelope targets, the province of record writes them into law, and the window is measured against CSA A440.2:22 — U-factor, SHGC, air leakage and the ER number that combines them. The cold case is the heating case. The window is the largest heat-loss surface on the wall, and the schedule states the build, the rating and the report per opening.
The Canada brief: the cold case first
Canada is a heating country. The design winter is long, the heating season is the whole point of the envelope, and the window is the surface that gives the heat away. Natural Resources Canada puts the loss through and around the windows at up to 25% of the total for a home, and the same arithmetic runs on every villa project on the line. The glazed area is the largest single variable on the wall, and a big opening costs more in January than a small one.
The code answers that with limits, and the standard answers it with measurement. The building code sets the maximum thermal transmittance the fenestration assembly may carry, by jurisdiction and by compliance path. CSA A440.2:22 then measures the unit — the U-factor, the solar heat gain coefficient, the visible transmittance, the air leakage — and combines them into the ER number for the low-rise residential heating case. The schedule quotes the build against both: the code line for compliance, the standard line for performance.
What the Canada energy code actually is
The Canada energy code starts as a national model document: the National Energy Code of Canada for Buildings, published by the National Research Council. The 2020 edition is the fifth — 1997, 2011, 2015, 2017, 2020 — and it carries three changes that matter on the window schedule. The maximum thermal transmittance values for the envelope assemblies, fenestration included, came down. Whole-building airtightness testing came in as a compliance option. And a four-tier performance path was added above the prescriptive route.
The 2025 national edition followed in December 2025. Neither edition is law on its own: the NECB is a model code, and each province and territory adopts it with or without changes. The practical read for an export order is one line on the schedule — the province of record and the edition that province references. A quotation that names the national edition without the provincial one is incomplete, and the drawing office asks for both before the RFQ goes out.
The provincial column: British Columbia, Ontario and Quebec
British Columbia runs the BC Energy Step Code, a provincial regulation introduced in 2017 and carried inside the BC Building Code. It is a performance path: the builder proves the envelope target, the systems target and the airtightness by measurement and modelling, not by prescriptive values. The Step Code has been the default compliance path since the May 2023 BC Building Code update, with Step 3 the Part 9 baseline for houses; the provincial timeline lifts Part 9 to Step 4 in 2027 and Step 5 in 2030, toward the 2032 net-zero-energy-ready target.
Ontario runs Supplementary Standard SB-10 inside the Ontario Building Code, currently the 2024 edition. SB-10 mixes NECB and ASHRAE 90.1 compliance paths, and the Part 9 non-residential checklists that mirror it carry fenestration limits: vertical glazing at U-2.15 W/m²·K in the lower degree-day zone and U-1.94 in the higher, with the SHGC held at 0.40 and 0.45 respectively, and the VT/SHGC ratio at 1.10 or better. The larger the glazed area on the wall, the more the project is pushed onto the modelling path.
Quebec runs Chapter I.1, Energy Efficiency of Buildings, of the Quebec Construction Code. The 2025 edition — the second, after the 2020 first edition — carries an amended NECB 2020 with the Quebec changes marked, keeps the same prescriptive requirements as the edition before it, and adds a winter maximum power demand test on the performance path. The Régie du bâtiment du Québec publishes it jointly with the National Research Council, which is why the document pack a Quebec project asks for reads like the national one with a provincial overlay.
The Canada line, standard by standard
| Line | Edition | What it sets |
|---|---|---|
| National Energy Code of Canada for Buildings | 2020, fifth edition | The model envelope targets; provinces adopt or amend |
| BC Energy Step Code | 2017, in the BC Building Code | Performance steps; Step 3 the Part 9 default since May 2023 |
| Ontario Building Code SB-10 | 2024 OBC edition | Prescriptive fenestration U and SHGC limits by degree-day zone |
| Quebec Construction Code Chapter I.1 | 2025, second edition | The amended NECB 2020, plus the winter power demand test |
| CSA A440.2 | :22, eighth edition | U-factor, SHGC, VT, I and CI; the ER number |
| ENERGY STAR Canada | Version 5, 2020 | U-1.22 or ER 34; air leakage 1.5 L/s·m² both ways |
What CSA A440.2:22 measures
CSA A440.2 is the Canadian fenestration energy standard, and the :22 edition is the eighth. It supersedes the :19 edition, and it covers the fenestration systems under AAMA/WDMA/CSA 101/I.S.2/A440 — the North American fenestration standard — from casements and sliders to sliding doors, side-hinged doors and unit skylights. The measured properties are the U-factor, the SHGC, the visible transmittance, the Temperature Index (I) and the Condensation Index (CI).
The ER number is the heating-season summary, and it is calculated rather than measured directly: ER = (57.76 × SHGC) − (21.90 × U) − (1.97 × L75) + 40. The L75 term is the air leakage at 75 Pa, taken as the average of the infiltration and the exfiltration measurements under the North American standard. The higher the ER, the better the unit balances solar gain against heat loss across an average Canadian heating season, and the rating applies to vertical units in low-rise residential buildings — the villa case, in other words.
The thresholds a buyer will meet
Three thresholds show up on a Canadian order under the Canada energy code line, and they sit at different levels. The ENERGY STAR Canada technical specification, Version 5 in force since January 2020, asks for a U-factor of 1.22 W/m²·K or lower, or an ER of 34 or higher, with the air leakage rate at 1.5 L/s·m² or lower in both directions; the Most Efficient recognition line for 2025 runs tighter again at U-1.05 or ER 40. The British Columbia Energy Efficiency Standards Regulation, Amendment 7, sets the product-side floor for residential windows and sliding glass doors manufactured after 1 January 2022 at U-1.61 W/m²·K, improved from 1.80.
The federal layer is a label, not a floor. The amendment to the federal Energy Efficiency Regulations covering manufactured fenestration products is drafted for products manufactured from 2028: a mandatory bilingual label in SI units, the U-factor, the SHGC and the visible transmittance on the label, the ER value optional, testing under CSA A440.2:22 or the NFRC 100-23 and 200-23 procedures — and no minimum performance requirement at all. That label replaces the ENERGY STAR Canada label when it lands. The honest schedule line is the program line the project targets, not a claim of a national minimum.
The cold-case build: what the schedule states
The build answers the climate, and the range already carries the parts. The casement line runs on a 70 mm thermal-break platform with multi-point locking across a full-perimeter gasket, airtightness Class 4 on every unit shipped. The glazing schedule for the cold case runs double or triple: a low-E coat on the warm side of the cavity, argon fill, a warm-edge spacer, and the triple build — 5+18A+5+15A+5, the build the entry-door sidelight already carries — where the unit is large or the exposure is hard. The IGU certification runs to ASTM E2190 or CAN/CGSB 12.8. The same build answers the Condensation Index: the warm-edge spacer and the sealed cavity hold the inner surface above the dew point through the heating season.
The thermal-break depth is the frame half of the same answer, and it is stated per range rather than per project: 70 mm on the casement platform, 110 mm on the structural lines, 55 mm on the awning. The schedule names the range, the break width and the wall thickness, and the U-factor on the quotation is the configured-unit value under CSA A440.2:22, not a family average. On the current range the aluminium lines run 30–45 days from approved shop drawings, and the glass build is the first line on the schedule because it is the first line the code reads.
The document pack: per order and per model
The rating travels with the model, not with the brand. The certification is issued by a body accredited by the Standards Council of Canada, or by the NFRC, against the configured unit, and the report names the configuration it covers — the frame line, the glass build, the hardware. A report for a different configuration is the gap the receiver catches, and the schedule states that the report must match the unit that ships.
From 2028 the federal label carries the same numbers on the product itself: the U-factor, the SHGC and the visible transmittance in SI units, bilingual, with the model identification code and the certification mark. The order pack keeps the report, the label data and the configuration reference together, so the yard checks three documents that agree instead of one claim on a catalogue page.
How to specify it on the schedule
- Name the province of record and the edition that province references — the national edition alone is not the compliance line.
- State the compliance path the project takes: the prescriptive limits, the performance path, or the ENERGY STAR line the developer targets.
- Put the U-factor and the ER on the schedule as configured-unit values under CSA A440.2:22, with the report reference.
- State the air leakage rate in both directions, and the airtightness class the frame carries.
- Name the glazing build per opening — double or triple, the low-E position, the gas fill, the spacer — with the IGU certification reference.
- Carry the Condensation Index and the Temperature Index where the project states an interior humidity target.
- Set the label and report requirements for the 2028 federal regime on orders that will ship into it.
Frequently Asked Questions
Is the Canada energy code one national code?
No. The National Energy Code of Canada for Buildings is a model code published by the National Research Council; each province and territory adopts it with or without changes. The schedule names the province of record and the edition that province references.
What does the ER number measure?
The heating-season balance of one window: ER = (57.76 × SHGC) − (21.90 × U) − (1.97 × L75) + 40, where L75 is the air leakage at 75 Pa averaged across infiltration and exfiltration. Higher is better, and the rating applies to vertical units in low-rise residential buildings.
Do Canadian windows carry the NFRC label?
They can be certified under either route: CSA A440.2:22 is the Canadian standard, and the NFRC 100-23 and 200-23 procedures are accepted alongside it. From 2028 the federal label carries the U-factor, the SHGC and the VT in SI units, bilingual, and replaces the ENERGY STAR Canada label.
Is U-1.22 the legal minimum in Canada?
No. U-1.22 is the ENERGY STAR line, not law. The product-side floor that does carry regulation is provincial — British Columbia sets U-1.61 for residential windows manufactured after January 2022 — and the building codes set envelope targets by compliance path.
Does the cold case mean triple glazing everywhere?
No. The build follows the opening: double glazing with low-E, argon and a warm-edge spacer covers most positions, and the triple build goes where the unit is large or the exposure is hard. The elevation and the unit size sit on the schedule, per opening.
What travels with the order?
The certification report per model, issued by an SCC-accredited body or the NFRC against the configured unit, the label data, and the configuration reference. The yard checks that the three agree with the schedule.
