KF 410 uPVC/Aluminum Windows: Internorm’s Most Versatile Window
Flush, square, rounded or contoured: the KF 410 uPVC/Aluminum is available in all four Internorm design styles. A powder-coated aluminum shell outside, I-tec Insulation inside and Passive House Institute certification make it a window architects can put on almost any facade.
One window system for the whole house
The KF 410 uPVC/Aluminum pairs an insulated six-chamber uPVC frame with an exterior shell of powder-coated aluminum. Internally it is the same certified window as the all-uPVC KF 410, with I-tec Insulation filling the frame chambers. Externally, the aluminum takes UV, rain and ice, and carries whatever colour the architecture asks for. Construction depth grows from 90 mm to 93 mm; the Uw stays as low as 0.62 W/m²K.
Where this version really separates itself is range. It is the KF 410 that offers the flush studio style alongside home pure, home soft and ambiente, so a single system can cover a minimalist addition and a traditional main house. Its cladding can also be matched to Internorm’s timber-aluminum windows such as the HF 410, so you can put timber inside the living spaces and uPVC in bathrooms and mudrooms while the facade reads as one.
For builders and architects, that consistency pays off: one profile family, one set of Passive House data and one installation detail, with the matching KV 440 integrated-blind window at the same 93 mm depth for rooms that need shading.
Four design styles
Every style uses the same certified KF 410 core. What changes is the shape of the frame and sash, and with it the character of the window from inside the room.
studio: flush
Clean lines and a minimalist, flush profile that lets large glazing become the feature. On the KF 410, studio is available only with aluminum cladding, which makes this the version for design-led modern homes.
home pure: square-edged
Simple straight lines that blend into contemporary architecture. The square-edged frame and sash are a dependable choice for modern custom homes and infill builds.
home soft: rounded
Rounded edges create a harmonious, sleek frame that sits easily in transitional interiors, where crisp modern lines might feel too severe.
ambiente: contoured
Profiled, contoured edges bring traditional detailing to the frame, giving heritage-inspired facades the character they need with a modern aluminum finish outside.
KF 410 uPVC/Aluminum technical data
Best-case figures from the InterHaus data sheets, available for each design style, and Internorm’s 2026/27 technical overview.
| Construction | Six-chamber uPVC frame with I-tec Insulation and powder-coated aluminum cladding |
|---|---|
| Construction depth | 93 mm |
| Profile width | 76 mm frame + 36.5 mm sash |
| Sightline, frame and sash | 113 mm |
| Sightline, flying mullion (two sashes) | 133 mm |
| Sightline, mullion (two sashes) | 187 mm |
| Thermal insulation (Uw) | As low as 0.62 W/m²K; 0.71 W/m²K with the standard coating |
| Sound reduction | 34–47 dB |
| Security | Up to RC 2, fully concealed locking |
| Gaskets | Three continuous gaskets, external gasket in light grey or black |
| Certification | Passive House Institute certified |
| Design styles | studio, home pure, home soft, ambiente |
| Exterior colours | Standard HM, hirest HF/HFM, HDS and EL01/EL02 stainless-steel look |
| Options | Factory-fitted French (Juliet) balcony |
| Expected service life | 40+ years |
Values vary with window size, glazing and design style. We supply project-specific data with every specification.
Larger glass, lower heat loss
On a KF 410, the triple-glazed unit insulates better than the frame around it: the glass Ug outperforms the frame Uf. That has a counter-intuitive consequence. The larger the window, the more energy efficient it becomes overall, because a bigger share of the opening is high-performance glass rather than frame. It is why window sizing belongs in the energy model, not just on the elevation drawings.
The glass itself is specified to the project. With more than 400 glass combinations and the option of custom SHGC and Ug values, we can balance welcome solar gain on south elevations against overheating on west ones, using argon or krypton fills and Internorm’s Low Carbon iplus coating as standard. The insulated frame then keeps the edges warm, so the whole window performs in a −20°C cold snap, not just the centre of the glass.
The comfort payoff is a warm inner surface. Instead of a cold pane pulling heat from the room and dropping a draft to the floor, the glass stays close to room temperature. Condensation becomes far less likely, and a sofa or dining table can sit right at the glass in mid-winter.
Notes for architects and builders
The details that matter when you are drawing and building with the KF 410 uPVC/Aluminum.
I-tec Insulation as standard
Granules evenly fill the frame chambers, improving the frame’s own insulating value within its 93 mm depth.
Insulated and reinforced 360°
The hybrid frame is insulated and reinforced all the way round, and it moves less with temperature swings than many single-material frames, protecting the air seal over time.
Gasket colour to suit the cladding
Three continuous gaskets, with the external gasket available in light grey or black so dark facades stay clean-lined.
Matching blinds window
Where a room needs shading, the KV 440 integrated-blind window shares the 93 mm depth and combines easily with the KF 410.
French balcony options
A French or Juliet balcony turns a floor-to-ceiling KF 410 on an upper floor into a full-height opening, with no projecting balcony. Internorm’s versions are factory fitted and integrated into the window or door frame. Guard heights must comply with the applicable building code.
Glass balustrade
A panel of laminated safety glass (LSG) with stainless steel edge protection. The most transparent of the three, it keeps the view completely open.
Round stainless steel rod
Slim round stainless steel rails give a soft, classic line that sits well with home soft and ambiente frames.
Angular stainless steel rod
Square-section stainless steel rails with a crisp, architectural profile that pairs naturally with studio and home pure.
Concealed RC 2 security, with a clear upgrade path
The KF 410 uPVC/Aluminum is rated up to resistance class RC 2. All locking and hinge hardware is concealed in the profile, so there is nothing on the exterior aluminum to attack, and the concealed hinges prevent the sash from being levered out. I-tec Glazing bonds the triple-glazed unit into the sash, so the glass cannot be pushed out of the frame.
French balcony glass is laminated, and laminated safety glass can also be specified in the window itself for exposed ground-floor openings. Lockable handles and turn locks add child safety, and opening sensors report whether each window is open, tilted or locked.
When a brief calls for RC 3, specify the KF 510 uPVC/Aluminum or KF 520 instead. Their I-tec Secure flap locking, standard on both, is not available on the KF 410.
KF 410 uPVC/Aluminum against the alternatives
The KF 410 alongside the premium-design KF 510 and KF 520, and the HF 410 timber-aluminum window it mixes with.
| KF 410 uPVC/Alu | KF 510 uPVC/Alu | KF 520 uPVC/Alu | HF 410 timber/alu | |
|---|---|---|---|---|
| Interior face | uPVC | uPVC | uPVC | Timber |
| Uw, best value (W/m²K) | 0.62 | 0.64 | 0.63 | 0.64 |
| Sound reduction (dB) | 34–47 | 34–48 | 33–46 | 33–46 |
| Security, up to | RC 2 | RC 3 | RC 3 | RC 2 |
| Locking | Concealed | I-tec Secure | I-tec Secure | Concealed |
| Construction depth (mm) | 93 | 93 | 93 | 85 |
| Sightline, frame and sash (mm) | 113 | 95 | 85 | 108 |
| Design styles | studio, home pure, home soft, ambiente | home pure | studio | studio, home pure, home soft, ambiente |
Values as published in Internorm’s 2026/27 window technical overview and on the InterHaus HF 410 page.
“This was a VIP experience from start to finish. Fast, friendly and effective service. It really helped that Vik is an architect, she was able to guide us through the entire process and coordinated directly with our designer. The windows are top-notch, but the service was better than the product.”
KF 410 uPVC/Aluminum FAQ
Start with the architecture. Studio’s flush profile suits minimalist, glass-led designs; home pure fits most contemporary homes; home soft works in transitional interiors; ambiente suits traditional and heritage-inspired facades. All four share the same KF 410 core, so the choice is mainly about appearance, and we are happy to talk it through against your drawings.
Yes. Internorm offers factory-fitted French balconies for the KF 410 with a laminated safety glass balustrade, round stainless steel rods or angular stainless steel rods, all integrated into the window or door frame. They are ideal where a projecting balcony is not possible, and guard heights must meet the building code.
Yes. The aluminum cladding can be matched to Internorm’s timber-aluminum windows such as the HF 410, so the exterior looks uniform while you choose timber for living spaces and uPVC for bathrooms, laundry rooms or a basement suite. Internorm notes that uPVC is particularly well suited to rooms with high humidity.
Yes. InterHaus offers side entrance doors built on the KF 410 system, in uPVC-all or uPVC-aluminum, with a multi-point lock and knob cylinder, a low threshold and heavy-duty side hinges. The KF 410 side door reaches a Uw as low as 0.70 W/m²K.
Our product specialists have an architectural background and provide technical support from early design through to site. We supply data sheets for each design style, warehouse locally in Ontario and provide installation guidance and supervision. For Passive House projects we aim to quote within 72 hours.
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Dimensions, profile sections, glazing build-ups and performance values — ready for your architect or builder.
Specify the KF 410 uPVC/Aluminum
Share your drawings, window schedule and colour intent, and we will return a KF 410 specification with design style, glazing and options for each opening. Passive House projects get a quote within 72 hours, and our team will coordinate directly with your architect or builder.