What makes a window "energy efficient" in Canada?
A tested number. NRCan's ENERGY STAR specification, Version 5.0, certifies a window at a U-factor of 1.22 W/m²·K or lower, or an Energy Rating of 34 or higher, plus an air-leakage limit of 1.5 L/s/m². Lower U-factor means less heat escaping.
Which ENERGY STAR climate zone is Calgary in?
Under the current specification, none. Version 5.0, in force since January 1, 2020, sets one national criterion and does not mention climate zones. Older versions split Canada into zones, and some brochures still quote them. If a seller quotes a zone, ask which version of the specification they mean.
Where does a window lose energy?
Three places, and NRCan's Energy Rating formula counts all three: heat through the glass and frame (U-factor), air leaking past the sash, and free heat gained from the sun. That's why the seal matters as much as the glass. A tilt-and-turn clamps the sash onto a continuous gasket when you lock it.
How do REHAU windows compare with the ENERGY STAR limit?
ENERGY STAR's ceiling is a U-factor of 0.21 in imperial units. REHAU lists ARTEVO at U-values down to 0.14 with triple glazing. "Down to" is the ceiling of a specific tested build. Your window's number depends on glass build — ask for the spec on the quote.
What does the City's Home Energy Performance Map show?
The City of Calgary map shows scores for single-family homes, duplexes, townhomes and rowhomes. Digital scores are estimates from home size and construction year; EnerGuide labels come from a registered energy advisor. Scores don't update when you renovate; a post-retrofit EnerGuide evaluation can be submitted.
What do energy-efficient windows cost per opening?
Installed prices per opening in Canadian dollars, by REHAU line and wall type, from our published table. Triple-pane glass is included in every line. What moves a price inside its band is on the 2026 cost page; add up the house with the estimator.
| REHAU line | Standard retrofit | Stucco or brick wrap | Custom shape or structural |
|---|---|---|---|
| Brilliant Design (70 mm) | $1,800–2,400 | $2,200–2,800 | $2,800–3,800 |
| Synego (80 mm) | $2,300–3,000 | $2,800–3,500 | $3,400–4,600 |
| Artevo (80 mm) | $3,500–4,800 | $4,200–5,500 | $5,000–7,500 |
Is there a rebate or loan for windows?
I found no window grant open to Calgary homeowners right now. Alberta SHARP is open: a low-interest home equity loan up to $40,000 at 4.45%, covering window replacement, for homeowners 65+ with household income of $75,000 or less and at least 25% equity. Calgary's CEIP is closed until winter 2026/27. Details: window financing in Calgary.
How does buying work, and who installs?
It starts with you. Describe the project in four quick steps on the start page. I visit a home only when the homeowner invites me first. Then a free measurement, and PWS sends a written quote. Already holding another quote? Run it through the free Window Quote Check first.
Permanent Windows Solutions supplies and installs the windows. I'm a specialist there and I earn commission. European Window Guy is my practice at PWS, not a separate manufacturer or installer.