Double-glazed windows in Berwick & South East Melbourne.

The IGU build (the glass sandwich).

• Clear + Low-E + argon — the standard. 4mm clear outer + 12mm argon cavity + 4mm Low-E inner. U 1.6 W/m²K, SHGC 0.55. Suits north and east orientations.
• Tinted + Low-E + argon — for hot west-facing rooms. SHGC drops to 0.30–0.35 to block summer afternoon heat. ~$80–$120/window premium over clear.
• Laminated + Low-E + argon — safety glass (required for low-level glazing within 750mm of the floor and within 300mm of a door). Also a useful acoustic upgrade.
• Acoustic asymmetric build — 6mm float + 10.38mm laminated with optimised cavity. Rw 38–42 dB. For Mulgrave Fwy / Princes Hwy / Moorabbin flight path homes. ~$2K–$3K/window premium. See acoustic glazing.
• Triple-glazed — rare in SEM, only justified on extreme north-facing passive-house builds or homes targeting 8–9 star NatHERS. Adds ~$300–$500/window over double.

Frame options.

• Thermally-broken aluminium — the default for full-replacement jobs. A nylon thermal break in the frame section stops heat conducting through the aluminium. Whole-of-window U ~1.7–1.9. Powder-coated to any standard or custom colour. The growth-corridor / new-build default.
• Timber rebate IGU drop-in — keep your existing 80s or earlier timber sashes, we machine new beads and drop a 20mm IGU into the original rebate. Saves $400–$700/window. Best for heritage, Old Berwick, period homes where the sash is still beautiful.
• New timber frames — thermally-broken solid timber (Western Red Cedar, Accoya, or treated Vic ash). Premium look, period-appropriate, U ~1.6–1.7. ~$200–$400/window premium over aluminium.
• uPVC frames — rare in our market but available. Excellent thermal performance, lower price point, harder to repair than aluminium. Limited colour range.

Window operation styles.

• Awning — hinged at top, opens outward. Best ventilation in light rain. Standard kitchen / bathroom.
• Casement — hinged at side. Full opening, traditional look. Pairs with timber frames.
• Sliding — two-panel or three-panel. Standard 80s/90s replacement. Tighter seal in modern thermally-broken frames vs original mill-finish.
• Double-hung — vertical sliding, period-appropriate. Both sashes operable.
• Fixed / picture window — non-operable, largest IGU sizes possible. Best thermal performance (no operable seal to leak).
• Tilt-and-turn — European style, tilts inward at top for vent + opens fully for cleaning. Premium spec.

Pricing — installed.

Standard single window retrofit (up to 1.2m × 1.2m, argon clear Low-E, thermally-broken aluminium): $800–$1,500/window. Full-house retrofit (15–20 openings): $18K–$35K depending on frame type and any acoustic or laminated upgrades. VEU rebate of $3K–$6K typically offsets ~15–20% of full-house cost.