uPVC Aluminum Windows for Ontario's Freeze, Thaw and Summer Sun
A uPVC/aluminum window gives each material the job it does best: a powder-coated aluminum shell takes the weather, and a six-chamber uPVC core keeps the heat in. The result is a low-maintenance window in hundreds of exterior colours, with a service life of 40+ years and Uw values down to 0.62 W/m²K.
Aluminum takes the weather. uPVC keeps the warmth.
Look at a cross-section of a KF 410 or KF 510 and you see two distinct layers. The room side is Internorm's uPVC profile, with 4 mm walls around a multi-chamber core that resists the transfer of heat and cold. Over the outside sits a shell of thick, Grade A aluminum, powder-coated in the colour you choose.
Each layer covers the other’s weakness. uPVC insulates superbly but offers limited exterior colour; aluminum takes almost any colour and stands up to weather, but conducts heat. Put each where it works best and the frame is both warm and tough.
The frame is also insulated and reinforced through 360 degrees. That matters in Canada, where the same window sees deep winter cold and full summer sun. This hybrid expands and contracts less than many frame materials on the market, so seals stay tight and sashes stay square year after year.
uPVC/aluminum series compared
Cladding adds 3 mm to each frame’s depth but leaves the thermal core untouched, so the figures track the all-uPVC versions closely. The KF 510 is the one to note: clad, it reaches 48 dB of sound reduction.
| KF 310 | KF 410 | KF 510 | KF 520 | |
|---|---|---|---|---|
| Uw, as low as (W/m²K) | 0.69 | 0.62 | 0.64 | 0.63 |
| Uw, standard coating (W/m²K) | 0.76 | 0.71 | 0.72 | 0.70 |
| Sound reduction (dB) | 33–45 | 34–47 | 34–48 | 33–46 |
| Security, up to | RC 2 | RC 2 | RC 3 | RC 3 |
| Locking | Concealed | Concealed | I-tec Secure | I-tec Secure |
| Construction depth | 74 mm | 93 mm | 93 mm | 93 mm |
| Sightline, frame + sash | 107 mm | 113 mm | 95 mm | 85 mm |
| Design styles | Home Pure, Home Soft, Ambiente | Studio, Home Pure, Home Soft, Ambiente | Home Pure | Studio |
| Integrated-blind companion | KV 350 | KV 440 | — | — |
Figures from InterHaus product data and the Internorm 2026/27 catalogue; final values depend on size and glazing. The KV 350 and KV 440 windows with integrated blinds share the KF 310 and KF 410 construction depths, so they sit flush beside them.
What cladding adds to a uPVC window
Hundreds of exterior colours
Standard powder coats, fine-structure and metallic finishes, intensive HDS colours, stainless-steel looks and the RAL programme. Inside, the window stays clean uPVC white or decor.
Colour that stays put
Internorm's highly weather-resistant aluminum coating is designed for colour stability, and its warranty covers powder-coated surfaces against unnatural colour change and cracking.
A shield for the core
The shell takes direct UV, sleet and wind-driven rain, so the uPVC behind it is left to do one job: insulate.
Same warm core
Behind the shell sits the full six-chamber uPVC profile with triple gaskets. Cladding costs nothing in insulation: the KF 410 still reaches Uw 0.62 W/m²K.
Clad-only design styles
Some looks exist only with cladding: the KF 410 in flush Studio and the KF 310 in square-edged Home Pure are built exclusively as uPVC/aluminum.
Quiet under a flight path
Triple glazing and three gasket layers cut outside noise by up to 47 dB on the KF 410 and up to 48 dB on the KF 510, softening aircraft, traffic and lawn equipment.
Exterior colour families
Colour applies to the aluminum shell only, so a deep grey facade can sit over crisp white interiors. Not every colour is available on every window, and printed or on-screen colours can differ, so we show original samples in the showroom.
Standard colours
Sixteen standard powder-coat shades. All are highly weather-resistant except M916, which is facade quality.
Fine-structure & metallic
The hirest range adds fine-structure (HF) and metallic fine-structure (HFM) finishes, applied with a special highly weather-resistant powder coating for a subtle textured surface.
HDS colours
Eight intensive HDS colours for richer, more saturated tones. Internorm notes that slight variation is possible with these shades.
Stainless-steel look & RAL
EL01 matt and EL02 gloss reproduce the look of stainless steel, and the Internorm RAL programme opens further facade-quality colours for projects with a set palette.
Locking flaps instead of mushroom cams
Conventional tilt & turn hardware locks with pins or mushroom cams that hook into keepers on the frame. The KF 310 and KF 410 use a refined, concealed version of that system, with octagonal mushroom cams and solid designer locking elements, and reach RC 2.
The KF 510 and KF 520 go further with I-tec Secure, a mechanism available only from Internorm. When you turn the handle, flaps integrated into the sash press into the frame on all four sides, which makes the window virtually impossible to lever out. With the optional lockable handle both reach RC 2 N as standard, and RC 3 is available on request.
Because almost nothing protrudes from the sash and the frame parts are nearly invisible, the frame face is a smooth, easy-to-clean surface. The Secustik handle, with a jamming device that resists manipulation from outside, is standard on both. Our I-tec innovations page explains the full technology family.
Why a larger window can be the more efficient one
It sounds backwards, but with Internorm triple glazing a bigger window often performs better than a small one. The glass value (Ug) outperforms the frame value (Uf), so as the pane grows relative to its frame, the whole-window value (Uw) improves. Internorm puts it simply: choose triple instead of double glazing and you can add 40% more glass area without increasing your heating costs.
That is why uPVC/aluminum is a frequent choice for Passive House and Net-Zero construction. The KF 410 uPVC/aluminum is certified by the Passive House Institute and is one of the most proven Passive House window systems available in Canada. Our Passive House team supports architects and builders with technical data, and Passive House projects get a quote within 72 hours.
Airtightness is the other half of the story: the triple gasket system seals sash to frame on every side, so the heat you pay for stays indoors.
One facade, two interiors
Internorm builds its uPVC/aluminum and timber-aluminum windows with the same weather-resistant aluminum cladding. From the street, every window on the house reads as one family, while inside you choose the material room by room.
The classic split puts uPVC/aluminum in bathrooms, ensuites and laundry rooms, where humidity is high and a non-porous, wipe-clean surface is the practical answer, and timber-aluminum in living rooms and bedrooms, where real wood adds warmth. The catalogue pairs the KF 510 with the HF 510 and the KF 520 with the HF 520, and the KF 410 and HF 410 both come in all four design styles.
It also helps manage budget on a large project: timber where you touch it every day, uPVC where easy care matters more.
How uPVC/aluminum handles a Canadian year
Windows in Ontario and Québec face long stretches below freezing, rapid swings around zero in spring and fall, wind-driven rain and strong summer UV. Each part of the hybrid answers one of those.
- Cold: six chambers and triple glazing keep the inner pane warm, which improves condensation resistance and removes the chill you feel near ordinary windows.
- Freeze-thaw: the non-porous uPVC core cannot soak up water, so there is nothing to swell, rot or split when moisture freezes.
- Wind and rain: three continuous gaskets keep driving rain and air out, while the aluminum shell protects the profile from direct exposure.
- Sun: the powder-coated shell shields the uPVC from UV and holds its colour through decades of summers.
- Renovation payback: up to 30% of a home’s heat can escape through old windows, which is where a replacement earns its keep.
“My preferred window supplier for any of our projects with ambitious sustainability or indoor comfort goals. They have been easy to work with, and responsive when I need a problem solved. Internorm products have served me well, and these are the best, most reliable suppliers I have found in eastern Canada.”
uPVC/aluminum questions, answered
Not warmer, just different. Both share the same uPVC core, so Uw and sound figures are almost identical. Cladding adds a weather-resistant exterior in hundreds of colours and unlocks clad-only styles such as KF 410 Studio, with a frame 3 mm deeper. If white outside suits the house, all-uPVC is the more economical route.
InterHaus quotes an expected service life of 40+ years for uPVC/aluminum windows, with minimal maintenance. Internorm also provides a 30-year repair assurance, so its products can be repaired to full function over three decades.
The cladding uses Internorm's highly weather-resistant powder coatings, chosen for colour stability. Powder-coated aluminum surfaces are covered by Internorm's warranty against unnatural colour change and cracking; the full terms are in the Maintenance, Care and Warranties Manual supplied with your windows.
RC (resistance class) ratings are European burglary-resistance classes; a higher class withstands a more determined attempt with tools. KF 310 and KF 410 reach RC 2. KF 510 and KF 520, with I-tec Secure, reach RC 2 N as standard with a lockable handle, and RC 3 on request.
If you want shading protected between the panes, the KV 350 is designed to combine with the KF 310 and the KV 440 with the KF 410, so one room can mix both without a change in frame depth.
The uPVC/aluminum range
KF 310 uPVC/Aluminum
Compact 74 mm depth in three design styles, including clad-only Home Pure.
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KF 410 uPVC/Aluminum
Passive House certified and available in all four design styles, Studio included.
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KF 510 uPVC/Aluminum
Slim square sightlines, I-tec Secure as standard and a perfect match for the HF 510.
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KF 520 uPVC/Aluminum
Flush Studio frame with the sash hidden from outside; pairs with the HF 520.
ExploreChoose your colour, then your window
Bring elevations or a photo of the house and we'll help settle colour, series and opening layout, then quote supply and installation anywhere in Canada. Original colour samples are at our Oakville showroom.