Oknalux supplies and installs double glazed uPVC windows across Sydney and greater NSW from our showroom in St Marys. Our IGLO uPVC window frames are built on 5-chamber and 7-chamber European profile systems with Maco multi-point locking hardware, EPDM double and triple sealing, and steel reinforcement as standard.

Every frame carries a 10-year warranty. Every double glazing unit carries a lifetime guarantee. If you find a like-for-like quote cheaper within 7 days of ordering, we match it and take a further 3% off.

IGLO 5
(standard)

IGLO Light
(slimline)

IGLO Energy
(highest performance)

IGLO Premier
(awning/outward opening)

Energy Saving

Noise Reduction

Safety and Durability

uPVC Double Glazed Windows

Why Sydney Homes Are Moving to uPVC Double Glazing

Sydney’s climate puts two competing demands on a window. Summer means long stretches of direct heat load, especially on west-facing glass. Winter means overnight temperature drops that turn single-glazed aluminium into a condensation trap. A window that solves one and ignores the other is only half a window.

uPVC solves both because the frame itself does not conduct. Aluminium is roughly a thousand times more thermally conductive than uPVC, which is why an aluminium frame will sweat on a cold Sydney morning even when the glass beside it is dry. Pairing double glazed glass with a conductive frame throws away a large part of what you paid for.

The second driver is noise. Sydney has flight paths, arterial roads, and rail corridors running through dense residential areas. Our IGLO 5 system delivers a 34 to 44 decibel reduction depending on the glass package specified, and IGLO Energy reaches 35 to 46 decibels. For a home under the Kingsford Smith flight path or fronting Parramatta Road, that difference is the difference between sleeping and not.

uPVC Windows and BASIX Compliance in NSW

Every new dwelling and most major renovations in NSW must satisfy BASIX, and glazing is one of the largest single levers in the thermal assessment. The frame material is not a footnote in that calculation, it is part of it. A uPVC frame with a lower whole-of-window U-value gives your assessor more room elsewhere in the design, which often means you can keep the large openings you actually want instead of shrinking them to pass.

Bring us your BASIX certificate or your assessor’s glazing schedule and we will specify frames and glass to meet the target. If you are still in design, talk to us before the assessment is locked, not after.

Oknalux is listed with WERS, the Window Energy Rating Scheme, and our products are manufactured by Drutex S.A., which holds AS 2047 certification for the Australian market alongside ISO 9001.

Manufacturer-tested whole-window U-values, measured to EN 674 on a 1230×1480mm window:

Profile	Uw
IGLO Light	1.0 W/m²K
IGLO 5	0.94 W/m²K
IGLO Energy	0.79–0.89 W/m²K

One caveat worth stating plainly, because most suppliers do not. Australian and European U-value tests use different window sizes. Australia tests at 600×1500mm, Europe at 1230×1480mm. The European test has proportionally more glass and less frame, so the same window returns a slightly different number depending on where it was tested. A window rated 1.6 in Australia might return 1.9 in Europe. The figures above are European, which means they are the more conservative of the two.

Our uPVC Window Frame Systems

Three profile systems, each with published technical data.

	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

All three systems use Maco Multi Matic KS hardware with two anti-burglary bolts as standard, galvanised steel spacer bars with optional Swisspacer Ultimate, and are available in over 30 Renolit foil colours including wood-grain textures, with different colours inside and out.

IGLO 5 suits most Sydney homes. A 70mm five-chamber frame taking up to 40mm of glass covers the great majority of residential replacements and new builds.

IGLO Light is the slimline option where sightlines matter more than absolute thermal numbers. Heritage-sensitive facades in the inner west and eastern suburbs are the usual case.

IGLO Energy is for Passive House projects, homes on serious noise corridors, and anywhere the BASIX target is tight. The 82mm seven-chamber frame takes 48mm of glass and accepts quadruple glazing. Glass fibre reinforcement is available in place of steel, which improves thermal performance further by removing the thermal bridge the steel creates.

uPVC Window Styles

Tilt and Turn Windows

Tilt in from the top for secure ventilation, or swing fully inward for maximum airflow and easy cleaning from inside. Practical on upper floors where external cleaning is awkward.

Awning Windows

Top-hinged and outward opening, built on our IGLO Premier frame with multi-point locking. Suits situations where you want ventilation during rain.

Casement Windows

Side-hinged and outward opening. The straightforward choice for bedrooms and living areas where a full clear opening matters.

Fixed Windows

No opening sash, which means the best thermal and acoustic numbers of any configuration. Ideal as picture windows and highlights.

Sliding Windows

Horizontal sliding sashes for openings where a swinging sash would obstruct a walkway or outdoor area.

uPVC vs Aluminium vs Timber in Sydney

	uPVC	Thermally broken aluminium	Timber
Frame conductivity	Very low	Moderate	Low
Typical lifespan	20–35 years	Up to 45 years	35–45 years
Maintenance	Occasional wash	Occasional wash	Repaint or re-treat, roughly annually
Coastal performance	No corrosion	Salt pitting possible	Swelling and rot risk
Upfront cost	Lower	Higher	Higher
Finish options	30+ foils incl. wood-grain	Very wide	Widest, real timber
Condensation risk	Lowest	Higher	Low

Aluminium lasts longer as a material, and thermally broken aluminium is a genuinely good product. It simply costs more to reach the same thermal number. Timber remains the best choice where the building fabric or a heritage overlay demands it, and we supply it, but Sydney’s humidity and coastal exposure make the maintenance real rather than theoretical.

We also supply aluminium windows and timber windows if uPVC is not the right answer for your project. We would rather specify the right frame than sell you the wrong one.

Condensation, Mould and Sydney’s Humidity

Condensation forms when moist indoor air meets a cold surface. In most Sydney homes, the coldest surface in the room is the window frame, and if that frame is aluminium it is effectively a radiator running in reverse.

uPVC frames stay much closer to room temperature, so the dew point is rarely reached at the frame. Combined with a warm-edge spacer such as Swisspacer Ultimate in place of the standard galvanised bar, the cold bridge at the glass perimeter is reduced as well.

This matters beyond comfort. Persistent window condensation feeds mould in reveals, curtains and plasterboard. Homes in the inner west and lower north shore with poor cross-ventilation see this every winter.

Bushfire Ratings for Sydney Properties

Large parts of the Sydney basin sit in mapped bushfire prone land, particularly along the Hawkesbury, the northern beaches, the Blue Mountains fringe and the Sutherland Shire. If your property is mapped, your windows must meet the BAL assigned in your bushfire assessment.

Our uPVC systems with steel reinforcement are rated to BAL 29.

What uPVC Windows Cost in Sydney

Every Oknalux quote includes measure, manufacture, delivery and installation by our own team. We do not subcontract installation.

How Installation Works

Site measure. We measure every opening ourselves. Supplied measurements are not used for manufacture.
Specification. We confirm profile system, glass package, colour, hardware and opening type against your BASIX or acoustic requirement.
Manufacture. Your windows are made to your exact openings. Lead time is confirmed at order.
Removal. Existing frames come out, old sealant and debris are cleared.
Installation. New frames positioned and levelled, sill set, silicone applied, frames fixed, glazing beads fitted.
Finish and handover. Final silicone, hardware adjustment, operation demonstrated, site cleaned.

Sydney Service Area

We install across Sydney and NSW from our St Marys showroom, including the Inner West, Eastern Suburbs, North Shore, Northern Beaches, Hills District, Western Sydney, Sutherland Shire, Macarthur, the Central Coast, Blue Mountains, Wollongong and Newcastle. We also service the ACT.

Sydney showroom: 12 Harris Street, St Marys NSW 2760
Hours: Monday to Friday, 8:30am to 4:30pm
Phone: (02) 9833 2993

Book a free measure and quote for uPVC windows anywhere in Sydney. Call (02) 9833 2993, request a quote online, or visit our St Marys showroom Monday to Friday.

Gallery

Frequently Asked Questions

Do uPVC windows yellow in the Australian sun?

Quality uPVC does not. Our profiles are UV-coated and use a titanium dioxide sunscreen additive in the compound, which is what prevents the yellowing associated with cheap unstabilised PVC. Colour is applied as a Renolit foil rather than paint, so there is nothing to flake or fade off the surface.

How long do uPVC windows last in Sydney?

20 to 35 years for the frame, longer for premium profiles. uPVC does not rust in coastal air, does not rot in humidity, and does not swell or drop out of square. Our frames carry a 10-year warranty and the double glazing units carry a lifetime guarantee.

Are uPVC windows more expensive than aluminium?

Standard single-glazed aluminium is cheaper upfront. Compared against thermally broken double glazed aluminium, which is the fair comparison, uPVC is usually less expensive for equal or better thermal performance.

Can I retrofit uPVC windows into an existing Sydney home?

Yes. Most of our Sydney work is replacement rather than new build. See our retrofit double glazing Sydney page.

Will uPVC windows help with aircraft and traffic noise?

Substantially. IGLO 5 achieves 34 to 44 dB reduction and IGLO Energy 35 to 46 dB, depending on glass package. For flight path and arterial road properties we typically specify acoustic laminated glass with asymmetric pane thicknesses.

Do uPVC windows meet BASIX?

uPVC frames are among the strongest performing frame materials for BASIX glazing calculations. Send us your certificate or glazing schedule and we will specify to the target.

Are your windows suitable for bushfire prone land?

Our uPVC systems are rated to BAL 29. Provide your BAL assessment at quote stage and we will confirm compliance for your specific rating.

Do you manufacture in Australia or import?

Our profiles are manufactured by Drutex S.A. in Europe, one of the largest window manufacturers on the continent, and certified to AS 2047 for Australian conditions as well as ISO 9001. Measuring, project management and installation are handled by our own team out of St Marys.

What warranty do you offer?

10 years on frames, lifetime on double glazing units.