Oknalux supplies and installs uPVC double glazed windows through our IGLO range of European profile systems: 5-chamber and 7-chamber frames, Maco multi-point locking hardware, EPDM sealing, steel reinforcement as standard, and over 30 Renolit foil colours.
Frames carry a 10-year warranty. Double glazing units carry a lifetime guarantee.
uPVC Double Glazed Windows
| IGLO 5 | IGLO Light | IGLO Energy | |
|---|---|---|---|
| Positioning | Standard | Slimline | Highest performance |
| Chambers | 5 | 5 | 7 |
| Profile class | A-class, prime material | A-class, prime material | A-class, prime material |
| Frame depth | 70mm | 70mm | 82mm |
| Max glass thickness | 40mm | 40mm | 48mm |
| Sealing | Double EPDM | Double EPDM | Triple EPDM, incl. central foamed gasket |
| Noise reduction | 34–44 dB | 34–44 dB | 35–46 dB |
| Manufacturer Uw (EU test, 1230×1480mm) | 0.94 W/m²K | 1.0 W/m²K | 0.79–0.89 W/m²K |
| Glazing supported | Double / triple | Double / triple | Double / triple / quadruple |
| Reinforcement | Steel C-beam | Steel C-beam | Full steel frame + C-beam sash; glass fibre optional |
| Colours | 30+ Renolit foils | 30+ Renolit foils | 30+ Renolit foils |
Our IGLO profiles are manufactured by Drutex S.A., one of Europe’s largest window manufacturers, certified to ISO 9001 and to AS 2047 for the Australian market. Oknalux is listed with WERS, the Window Energy Rating Scheme.
All profiles are A-class and extruded from prime material rather than recycled stock. That distinction matters more than it sounds: recycled PVC profiles have inconsistent density and lower impact strength, which shows up as brittleness and colour drift over a twenty-year service life. A-class prime material is the specification you want and it is not universal in this market.
Hardware is Maco Multi Matic KS throughout, with two anti-burglary bolts as standard, and anti-burglary classes RC 2 and RC 2N available on request.
Manufacturer-tested whole-window U-values, EN 674, on a 1230×1480mm window:
| Profile | Uw | Standard glass package |
|---|---|---|
| IGLO Light | 1.0 W/m²K | Ug up to 0.7 W/m²K available |
| IGLO 5 | 0.94 W/m²K | Ug 1.0 W/m²K standard, 0.7 available |
| IGLO Energy | 0.79–0.89 W/m²K | Ug 0.5 W/m²K standard; 0.3 with krypton-filled quad |
IGLO Energy with a krypton-filled four-pane package reaches a glass U-value of 0.3 W/m²K, which is Passive House territory.
Why Australian and European U-values differ. Australia tests on a 600×1500mm window, Europe on 1230×1480mm. The European sample has proportionally more glass and less frame, so it returns a higher, more conservative figure for the same product. A window returning 1.6 in Australia may return 1.9 in Europe. The figures above are European. See our [technical info page] for the full calculation method.
Chamber count is the number of sealed air pockets in the frame cross-section. More chambers means more resistance to heat transfer, because each still-air pocket interrupts conduction. Five is standard. Seven is high performance.
Frame depth determines glass capacity. A 70mm frame takes up to 40mm of glass, enough for a double glazed unit with a wide cavity or a slim triple. An 82mm frame takes 48mm, enough for full triple or quadruple glazing.
Sealing is where most window failures start. Double EPDM means two continuous rubber seals between sash and frame. Triple means three. EPDM stays flexible far longer than the cheaper alternatives, which is why a well-sealed uPVC window still shuts tight after twenty years.
Reinforcement is required. Australian conditions demand steel inside the profile for structural stability and wind load resistance. The trade-off is that steel conducts, so on IGLO Energy we offer glass fibre reinforcement instead, which improves thermal performance by removing that bridge.
Tilt in from the top for secure ventilation, turn fully inward for maximum airflow and inside cleaning.
Top-hinged and outward opening on the IGLO Premier frame, with multi-point locking.
Side-hinged and outward opening for a full clear opening.
No opening sash, so the best thermal and acoustic performance available.
Horizontal sliding sashes where a swinging sash would obstruct.
uPVC is unplasticized polyvinyl chloride. Standard PVC has plasticisers added to make it soft and flexible, which is what you want in cable sheathing or vinyl flooring. Leave the plasticisers out and the material stays rigid and dimensionally stable, which is what you want in a window frame.
That rigidity is the whole point. A window frame has to hold its shape across decades of thermal cycling while carrying glass weight and wind load. Plasticised PVC would creep and the seals would progressively lose compression. uPVC does not.
uPVC was first extruded into window profiles in Germany in the 1960s and became the dominant frame material across the UK, northern Europe and much of the United States. Australia adopted it later, largely because aluminium was cheap and energy efficiency was not regulated. Both of those conditions have changed.
uPVC has very low thermal conductivity. Combined with multi-chamber geometry, the frame contributes to insulation rather than undermining it. This matters more than people expect: the frame is typically 20 to 30 percent of a window’s area, so a conductive frame can waste a large share of what double glazed glass delivers.
uPVC damps sound as well as heat. Paired with double glazing, IGLO 5 delivers 34 to 44 dB reduction and IGLO Energy 35 to 46 dB, depending on the glass package. Acoustic laminated glass with asymmetric pane thicknesses pushes this further by disrupting resonance between the panes.
No rust, no rot, no warping, no swelling. uPVC does not respond to humidity the way timber does or corrode the way steel and aluminium can in coastal air.
Profiles are UV-coated with a titanium dioxide sunscreen additive. Colour comes from Renolit foil laminated to the profile, not surface paint, so there is nothing to chalk, flake or fade off.
Maco Multi Matic KS hardware with two anti-burglary bolts as standard, plus a frame blockage that prevents the sash being lifted externally. Bolts screw directly into the steel reinforcement rather than into the plastic.
Warm soapy water occasionally. No painting, sealing or re-treating.
| uPVC | Thermally broken aluminium | Timber | |
|---|---|---|---|
| Frame conductivity | Very low | Moderate | Low |
| Lifespan | 20–35 years | Up to 45 years | 35–45 years |
| Maintenance | Occasional wash | Occasional wash | Repaint or re-treat, roughly annually |
| Corrosion | None | Salt pitting possible | Rot risk |
| Upfront cost | Lower | Higher | Higher |
| Finish range | 30+ foils incl. wood-grain | Very wide | Widest, real timber |
| Condensation risk | Lowest | Higher | Low |
| Recyclable | Yes | Yes | Yes |
Aluminium outlasts uPVC as a material and thermally broken aluminium is a genuinely good product, it simply costs more to reach the same thermal number. Timber is the right answer where heritage requirements or design intent demand real wood, and we supply it. uPVC wins on cost-to-performance for most residential applications, which is why it dominates in the markets that regulated window performance earliest.
We supply aluminium windows, timber windows and composite wood-aluminium windows as well.
The same frame properties apply to doors. Our uPVC door range includes sliding doors, French doors, bi-fold doors and entry doors, all available in matching profile systems and foil colours so windows and doors read as one system.
Over 30 Renolit foil colours, including smooth solids, textured finishes and wood-grain effects such as Golden Oak, Walnut, Mahogany, Winchester and Whitewashed Oak. Different colours can be specified inside and out, so you can run anthracite externally and white internally.
Cores are available in white or brown.
Oknalux operates from showrooms in Adelaide and Sydney and services South Australia, New South Wales and the ACT.
uPVC Windows Sydney → | uPVC Windows Adelaide → | uPVC Windows Canberra →
Unplasticized polyvinyl chloride. It is PVC without the plasticisers that make standard PVC soft, which leaves a rigid, dimensionally stable material suited to structural applications like window frames.
Broadly yes. Vinyl is the common North American term for the same material.
Cheap unstabilised PVC does. Properly stabilised, UV-coated profiles do not.
20 to 35 years, longer for premium systems. Our frames carry a 10-year warranty and glazing units a lifetime guarantee.
Yes. uPVC is fully recyclable and can be reprocessed into new profiles.
Double glazing has two panes and one sealed cavity. Triple has three panes and two cavities, better thermal and acoustic performance, more weight and cost. IGLO 5 supports double and triple. IGLO Energy supports up to quadruple.
Yes. Australian conditions require it for structural stability and wind load resistance. IGLO Energy offers glass fibre reinforcement as an alternative that improves thermal performance.
The spacer bar separates the panes at the edge of a double glazed unit. Standard galvanised steel conducts, creating a cold bridge at the glass perimeter. Swisspacer Ultimate is a low-conductivity alternative that reduces edge condensation.
