KF 510 uPVC Windows: Slim, Square and Locked with I-tec Secure
The KF 510 pairs a slim home pure frame with Internorm’s concealed I-tec Secure flap locking, built in uPVC inside and out. You get more glass, a clean square profile and security up to RC 3, with no exterior cladding to specify or maintain.
What’s built into every KF 510 uPVC window
These are the details that separate the KF 510 from an ordinary tilt & turn window, and why each one earns its place in a Canadian house.
I-tec Secure flap locking
Instead of mushroom cams, flaps in the sash swing out and press into the frame on all four sides as the handle turns. Levering the sash out becomes virtually impossible.
I-tec Insulation in the frame
Insulating granules fill the profile’s hollow chambers evenly. Internorm fits this as standard on only three systems, the KF 410, KF 510 and KV 440.
I-tec Glazing bond
The pane is glued to the sash around its entire edge, so it cannot be pushed out. The bond also improves the sash’s stability, insulation and sound reduction.
Three gaskets, 34–46 dB
Three circumferential gaskets keep out wind-driven rain and draughts and damp outside noise, for sound reduction of 34–46 dB depending on the glass.
Slim 95 mm sightline
A 70 mm frame and 25 mm sash leave more of each opening to glass, which matters most on narrow windows where a bulky profile swallows the light.
Easy-clean surfaces
The locking parts live inside the sash, so very little protrudes and the frame is a smooth uPVC face that wipes clean.
KF 510 uPVC technical data
Figures from InterHaus product data and Internorm’s 2026/27 technical overview. Final values depend on the size, glazing and hardware specified for each opening.
| Material | uPVC inside and outside, six-chamber profile |
|---|---|
| Design style | home pure (square edges) only |
| Thermal insulation, optimum | Uw as low as 0.63 W/m²K |
| Thermal insulation, standard coating | Uw 0.71 W/m²K |
| Sound reduction | 34–46 dB |
| Security | RC 2 N with lockable handle; up to RC 3 on request |
| Locking | I-tec Secure, fully concealed |
| Construction depth | 90 mm |
| Sightline, frame + sash | 95 mm (70 mm frame + 25 mm sash) |
| Sightline, two sashes | 100 mm flying mullion · 147 mm mullion |
| Gaskets | 3 circumferential, light grey outer gasket |
| I-tec technology | I-tec Secure, I-tec Insulation, I-tec Glazing |
| uPVC colours | White, Dark Grey |
| Expected service life | 40+ years |
Ask us for project-specific Uw, Ug and SHGC figures before you finalise drawings or an energy model.
Why I-tec Secure matters on a ground floor
Levering is the attack window hardware has to beat. Conventional locks resist at a handful of points; I-tec Secure resists along the whole perimeter. When the handle turns, flaps concealed in the sash open and press directly into the inner part of the frame on all sides, so there is no weak corner to work at.
As standard the KF 510 reaches RC 2 N with the optional lockable handle. On request it can be built to RC 3, the top class in Internorm’s uPVC range, shared only with the KF 520. The Secustik handle, listed as standard for the KF 510, stops the lock being shifted from outside, and laminated safety glass (VSG) stays in the frame when broken.
Because a tilt & turn sash opens inward, its hinges and locking hardware stay inside the house, out of reach. That makes the KF 510 a natural fit for walk-out basements, ground-floor bedrooms and any window hidden from the street.
Triple glazing tuned for an Ontario winter
Uw measures heat loss through the whole window, frame and glass together, in watts per square metre per degree of temperature difference. Lower is better. Internorm’s technical overview gives the KF 510 in uPVC a Uw of 0.71 W/m²K with the standard coating and as low as 0.63 W/m²K with the optimum glazing. InterHaus’s triple-glazed uPVC windows perform up to twice as well as the minimum Canadian Energy Star requirement.
The comfort difference shows at the glass. With our standard double Low-E iPlus Low Carbon coating, when it is −10°C outside and 23°C inside, the room-side surface of the pane stays around 21°C. A warm inner pane means no cold downdraft at the sofa and far less risk of condensation forming on the glass on a January morning. Our guide to condensation-resistant windows in Ontario explains why.
The glass itself is fully configurable. Working with Internorm and partners such as AGC Glass, we can draw on more than 400 glass combinations and adjust Ug and SHGC for each elevation: more passive solar gain on a south wall, more control on a west-facing room that overheats in summer.
- Uw as low as 0.63 W/m²K (0.71 with standard coating)
- I-tec Insulation granules in the frame chambers
- Inner pane around 21°C when it is −10°C outside
- Custom Ug and SHGC per elevation
Opening types for the KF 510
Choose tilt & turn, turn-only, tilt-only or fixed lights, or combine them in one frame, such as a fixed centre light between two tilt & turn sashes. Tilt for secure night ventilation; turn fully inward to clean the outside of the glass from indoors, no ladder needed.
Why choose uPVC on the outside too
All-uPVC is the more straightforward build: one material, inside and out. Internorm’s uPVC is non-porous, so it doesn’t absorb dirt or moisture and does not change colour over time. The exterior walls of the profile are 4 mm thick extrusions, rigid enough that the window needs no aluminum shell to protect it.
Fibreglass can take on moisture over time, and ordinary vinyl can turn brittle and fade under UV. Internorm uPVC is formulated to stay rigid and colour-stable, and it won’t warp, rot or swell. It never needs painting or sealing; upkeep is a regular clean and a little oil on the hinges about once a year.
Choose the all-uPVC KF 510 when white or dark grey uPVC frames suit the house and you want the simplest specification. If you want a powder-coated colour outside, or plan to match timber windows elsewhere in the house, look at the KF 510 uPVC/Aluminum instead.
KF 510 against the rest of the uPVC range
All four Internorm uPVC windows use three gaskets and triple glazing. The differences are in sightline, locking and design style.
| KF 310 | KF 410 | KF 510 | KF 520 | |
|---|---|---|---|---|
| Uw, as low as (W/m²K) | 0.69 | 0.62 | 0.63 | 0.63 |
| Uw, standard coating | 0.76 | 0.71 | 0.71 | 0.70 |
| Sound reduction (dB) | 33–45 | 34–47 | 34–46 | 33–46 |
| Security, up to | RC 2 | RC 2 | RC 3 | RC 3 |
| Locking | Concealed | Concealed | I-tec Secure | I-tec Secure |
| Construction depth (mm) | 71 | 90 | 90 | 90 |
| Sightline, frame + sash (mm) | 107 | 113 | 95 | 85 |
| I-tec Insulation | — | Standard | Standard | — |
| uPVC design styles | home soft, ambiente | home pure, home soft, ambiente | home pure | studio |
uPVC versions, from Internorm’s 2026/27 technical overview. KF 310 in home pure and KF 410 in studio are built only with aluminum cladding.
“Excellent windows and doors for noise and heating and cooling. We had to install new windows in some rooms in our old house and the difference between these ones and our old ones was obvious right away, no condensation in the winter, much quieter in summer (we had very noisy neighbours), very little heat loss so the rooms were warmer in winter and cooler in summer. We were so impressed that we installed them throughout our new house. Viktoryiya was so easy to work with, and the installation was excellent and problem free!”
KF 510 uPVC: common questions
Yes. Internorm’s uPVC is rigid, non-porous and formulated to resist UV, with 4 mm thick exterior walls, so it won’t warp, rot, swell or fade the way ordinary vinyl can. InterHaus gives the KF 510 an expected service life of more than 40 years. Aluminum cladding is a design and colour choice, not a durability requirement.
I-tec Secure is standard. With the optional lockable handle the window reaches RC 2 N, and it can be built to RC 3 on request. RC 3 is the highest class in Internorm’s uPVC range.
The KF 410 reaches a marginally lower Uw (0.62 against 0.63) and comes in three uPVC design styles, but tops out at RC 2 with conventional concealed hardware. The KF 510 trades that styling choice for a slimmer 95 mm sightline and I-tec Secure. If security or daylight leads your brief, choose the KF 510; for rounded or contoured profiles, see the KF 410 uPVC.
White and dark grey uPVC. White can be used on both faces of the window. If you need a darker or custom exterior colour, the aluminum-clad version opens up Internorm’s full exterior colour range.
A Uw as low as 0.63 W/m²K puts it in the range high-performance projects look for, and three gaskets keep it airtight. Send us your drawings and energy targets; for Passive House projects, InterHaus can return a quote within 72 hours.
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Dimensions, profile sections, glazing build-ups and performance values — ready for your architect or builder.
Plan your KF 510 windows with an architect-led team
Bring your drawings to our Oakville showroom or send them over. We’ll specify glazing, opening types and security class for each opening, then quote supply and professional installation anywhere in Canada.