Double Glazing Comparisons
Side-by-side comparisons for glazing types, frame materials, and installation approaches across Australia.
Double vs Secondary Glazing
Compare full retrofit double glazing with secondary glazing — thermal performance, noise reduction, cost, installation disruption, heritage suitability, and which approach delivers the best outcome for different property types and budgets.
Full retrofit double glazing from Everest Windows ($400–$800/window for standard retrofit, $10,000–$20,000 for a whole house) delivers superior thermal performance with a factory-sealed IGU, eliminates condensation between panes, and is invisible once installed. Secondary glazing from Magnetite ($250–$500/window, $5,000–$10,000 for a whole house) is 30–50% cheaper, retains original windows completely, and is the only viable option for heritage-listed buildings. Thermally, full double glazing achieves U-values of 1.2–1.6 W/m²K versus 2.5–3.0 W/m²K for secondary glazing. Both options significantly reduce noise — double glazing by 25–35dB and secondary glazing by 20–30dB. For most standard homes, full retrofit double glazing delivers better long-term value. For heritage properties or tight budgets, secondary glazing is the practical choice.
uPVC vs Aluminium Frames
Compare uPVC and aluminium window frames for double glazing — thermal performance, durability, maintenance, appearance, cost, and which frame material suits different property types and climates.
Thermawood's timber-to-timber retrofit approach ($500–$1,000/window) preserves original timber frames and adds double glazing without frame replacement — ideal for heritage homes. APS Double Glazing offers both uPVC and aluminium frame replacement options ($400–$850/window for retrofit, $850–$1,700 for full frame replacement). uPVC frames deliver the best thermal performance (thermally broken by design, U-values as low as 1.0 W/m²K), require minimal maintenance, and cost 20–30% less than equivalent aluminium frames. Aluminium frames are slimmer, stronger, and better suited to very large openings and modern architectural styles, but standard aluminium conducts heat readily — thermal break aluminium frames address this but at a premium cost. In hot climates like Perth, APS's expertise in heat-reflective glazing specifications delivers excellent results regardless of frame choice.
Retrofit vs Full Replacement
Compare retrofit approaches (secondary glazing and glass-only replacement) with full window replacement — cost, thermal performance, disruption level, frame condition requirements, and which approach makes sense for different situations.
Magnetite's secondary glazing ($250–$500/window) and glass-only retrofit options offer the lowest-cost entry point for improved window performance. Double Glazing Supplies' full replacement service ($350–$750/window for retrofit, $8,000–$16,000 for whole house) and supply-only IGU option ($150–$400/unit) provide the most affordable path to true double glazing. Retrofit approaches (secondary glazing or glass-only replacement) cost 30–60% less than full frame replacement and cause minimal disruption — typically 15–30 minutes per window with no structural work required. Full frame replacement delivers the best overall performance (new seals, thermal break frames, modern hardware) but costs more and takes 1–2 hours per window with some plaster and paint touch-up usually required. The right choice depends primarily on the condition of your existing frames.