U-factor
Lower is generally better for insulationHow quickly heat moves through the whole window or door system—not just centre-of-glass. Certified ratings account for the frame and edges.
THE RATINGS EXPLAINED
More than just
double or triple pane.
Real energy performance comes from the full product: glass, spacer, frame, weather seals, opening type and how everything is installed.
Natural Resources Canada rates fenestration products using standardized measurements. We'll help you compare the exact models available for your home instead of confusing you with vague claims.
Explore replacement windows ↗READ THE LABEL
Four numbers
worth knowing.
ENERGY STAR certification is product-specific. Compare tested performance data—not just brand names or marketing phrases.
Energy Rating (ER)
Higher is generally betterA Canadian measure combining insulation, solar heat gains and air leakage for windows and doors.
Solar Heat Gain (SHGC)
The right level depends on your homeThe fraction of sunlight's heat admitted through glazing. Orientation, shade, heating and cooling requirements affect the ideal value.
Air leakage
Lower means less unwanted air movementCertified models are tested for air infiltration and exfiltration. Installation quality and the existing wall also affect real-world drafts.
Source: Natural Resources Canada, Ratings and certification.
OUR MANUFACTURERS
Compare with
confidence.
We can compare the actual window or door you're considering. The same brand can offer many different performance levels based on size, opening style and glass selections.
KV Custom Windows & Doors
Windows • Entry doors • Patio doorsCompare whole-unit ratings by model, frame type, glass package, opening style and selected options.
Manufacturer ↗Vinylbilt
Replacement windowsCompare verified rating labels and glazing packages for your selected series, not a brand-wide average.
Manufacturer ↗VDK Windows & Doors
Windows • DoorsAsk for the precise certified window or door system rating for your quoted configuration.
Manufacturer ↗Vinylguard
Replacement windowsReview the product's certification, U-factor, ER and glazing details for the actual configuration.
Manufacturer ↗Entryguard
Entry door systemsInsulation depends on the complete door assembly, decorative glass, configuration and installation.
Manufacturer ↗What we'll compare on your quote
Product model, opening type, certified U-factor, ER, SHGC where applicable, glass layers, air-leakage rating, warranties and installation requirements.
No brand-wide rating or winner is claimed here. Manufacturer model-level test data must be confirmed before making product-specific comparisons. Some brands offer several product lines and ENERGY STAR certification applies only to qualifying models.
EASY HOME ENERGY ESTIMATE
What could you
save each year?
Five quick choices. We handle the calculations, using typical Eastern Ontario weather and published energy pricing where available.
We'll use an average window size. No measurements needed.
These are illustrative performance levels, not exact tested ratings for KV Custom Windows & Doors. We will add certified models as their data is verified. Manufacturer details ↗
How did we estimate this?
We assume average opening sizes, typical Eastern Ontario heating weather, and an approximate insulation level based on the era of your old products. No one needs to enter technical ratings.
Selected replacement: U-factor threshold used as an illustration. Certification can alternatively be based on ER; choosing this does not certify any manufacturer's product.
Energy price: Approx. 4¢ per delivered kWh of heat, including estimated variable delivery and furnace efficiency, not the monthly customer charge. Enbridge rates vary by Ontario zone and usage tier. Pricing source ↗
Published supplier rates and Ontario utilities change. Fixed monthly service/delivery charges are excluded because replacing windows doesn't eliminate them. Carbon factors and fuel conversion efficiencies are illustrative averages.
YOUR POTENTIAL SAVINGS
Based on 8 openings and an average windows replacement
Estimated yearly heating savings$96About 2,395 kWh less heat escaping through these openings each year.
Estimated yearly carbon reduction503 kg CO₂eOperational emissions; excludes manufacturing and disposal.
What that could add up to
5 years$499
10 years$1,049
25 years$3,069
Illustrative calculation, not a guaranteed saving or a full home-energy audit. Actual savings depend on existing product condition, sizes, installed performance, heating system, climate, air leakage and energy prices. Purchase/installation costs and cooling effects are not included.
Get a quote for my home ↗YOUR WHOLE HOME MATTERS
Windows are one part of the picture.
Upgrading windows and doors can improve comfort and reduce heat transfer, but overall results depend on insulation, HVAC efficiency, air sealing, solar exposure and the condition of the original products.
An estimate is the start of the conversation—not a promise of savings. Our team can discuss model-specific test labels and the right balance of comfort, design and budget.
Request an energy-conscious quote ↗