Retrofit or full replacement

Retrofit keeps your existing frames and typically prices 30 to 40 percent lower than full replacement, which includes new frames, hardware, and finishing. Many projects sit in between if some frames are due for an upgrade and others are sound and suitable for retrofit. 

Glass specification

The glass you choose affects comfort and price.

• Standard double glazing already improves warmth, comfort, and efficiency.
• High performance Low E coatings, like our SuperTherm range, boost insulation and help balance temperatures around the home.
• Laminated or acoustic glass reduces outside noise and creates a quieter interior.
• Safety glass ensures compliance in bathrooms, doors, and other higher risk areas.

Each option increases cost, and the benefits are practical and often immediate.

Access and complexity

Straightforward ground floor work is quicker and more economical. Multi storey homes, properties that need scaffolding, or sites with narrow or difficult access add more labour and time. Location can also play a role, with rural projects involving longer travel and urban sites sometimes restricted by parking or delivery constraints.

Finishes and colour

Standard colours and fittings are cost effective. Premium powder coat finishes, timber stains, or upgraded hardware create a more customised look and help new windows blend with the rest of the home, which naturally lifts the budget.

Value that shows up every season

Warmer in winter, cooler in summer

Double glazing reduces heat loss in winter, lowering heating demand and evening out cold spots near windows. In summer, the insulating air gap helps limit heat coming in, especially when paired with higher performance Low E glass like SuperTherm.

Condensation and moisture

Drier windows are more than cosmetic. Less moisture helps protect paint, sills, and curtains over time.

Sound reduction

Laminated and acoustic glass options, including SuperTherm Protect, can take the edge off traffic noise and busy neighbourhoods.

Comfort and value

Homes that are warm, dry, and quiet feel better to live in every day and tend to hold their value more strongly over time. Quality glazing is an upgrade that buyers increasingly look for.

If you are weighing up a staged approach, start with the rooms you use most or the coldest elevations, then expand as budgets allow.

What a typical homeowner can expect

Most homes fall into a predictable range once the details are clear. Room sizes, joinery type, opening styles, and glass area all influence cost, which is why online averages often miss the mark. The RetroGLAZE Cost Calculator uses your inputs to create a realistic range for New Zealand conditions and presents a clear summary that shows which choices move the number. When you are ready to take the next step, our team can guide you through what the results mean for your home and your project.

Ready to explore your numbers?

It takes about a minute to enter the rooms and window style of your home. You will see a range, a simple breakdown, and the key choices that move the dial, all in one place. Have a go here.