Double Glazing vs Triple Glazing NZ: Which Windows Are Best for Your Home?

Aug 4, 2021
4 min read

Updated: Jul 23

Wiping condensation from your windows might feel like a normal part of a New Zealand winter, but it doesn't have to be.

If you're comparing double glazing vs triple glazing, you're already thinking about creating a warmer, drier and more comfortable home.

Whether you're renovating, extending or building new, this guide explains the differences between the two glazing options, compares common window frame materials, and outlines the features that can improve your home's comfort and energy efficiency.

Why Your Windows Matter

Windows are responsible for a significant amount of heat loss in many older New Zealand homes.

Poorly insulated windows can lead to:

Cold draughts
Condensation
Higher heating costs
Rooms that are difficult to keep warm
Increased outside noise

Modern glazing systems help reduce heat loss while creating a warmer, drier and quieter home. The right choice will depend on your budget, your home's design and where you live.

Single Glazing vs Double Glazing vs Triple Glazing

Here's a quick comparison:

Feature	Single Glazing	Double Glazing	Triple Glazing
Thermal performance	★	★★★	★★★★
Condensation control	Poor	Good	Excellent
Noise reduction	Poor	Good	Excellent
Energy efficiency	Low	Good	Very Good
Cost	Low	Medium	High

Single Glazing

Single glazing consists of just one pane of glass.

While common in older homes, it provides very little insulation. During winter, the inside surface of the glass becomes cold, allowing moisture in the air to condense onto the window. This is why so many older homes experience wet windows each morning.

Double Glazing

Double glazing uses two panes of glass separated by a sealed air or gas-filled cavity.

This gap acts as an insulating barrier, helping to reduce heat transfer while also improving acoustic performance. Double glazing is now the standard choice for most new homes in New Zealand and is a significant upgrade when renovating older properties.

Triple Glazing

Triple glazing adds a third pane of glass, creating two insulating cavities.

The additional layer improves thermal performance even further, helping to minimise heat loss, reduce outside noise and further reduce the likelihood of condensation.

While it is more expensive than double glazing, it can be an excellent option for homes in colder parts of New Zealand or particularly exposed sites.

Is Triple Glazing Worth It in New Zealand?

It's a question we hear regularly.

The answer depends on your project.

For many homeowners, high-quality double glazing provides an excellent balance between performance and cost.

Triple glazing becomes more attractive if you're:

Building a high-performance home
Living in a particularly cold or exposed location
Wanting maximum thermal efficiency
Looking for the highest level of acoustic insulation

Rather than asking whether triple glazing is "better", it's worth asking whether the additional performance justifies the extra investment for your specific project.

Choosing the Right Window Frames

The glass is only part of the equation. The frame surrounding it also has a significant impact on performance.

Aluminium

Aluminium remains the most common window frame material in New Zealand.

It is:

Strong
Durable
Low maintenance
Available in a wide range of colours and finishes

The downside is that aluminium conducts heat very efficiently. Without a thermal break, heat can transfer through the frame much more easily than through other materials.

Thermally Broken Aluminium

A thermally broken aluminium frame includes an insulating barrier between the inside and outside sections of the frame.

This dramatically reduces heat transfer while retaining the strength and appearance of aluminium.

For many modern homes, thermally broken aluminium offers an excellent balance between durability and thermal performance.

Timber

Timber frames provide excellent natural insulation and have a timeless appearance.

They are particularly popular in architectural homes and heritage renovations.

They do, however, require more ongoing maintenance than aluminium.

uPVC

uPVC frames are becoming increasingly popular in New Zealand.

Because they conduct very little heat, they provide excellent thermal performance while requiring very little maintenance.

They are also resistant to corrosion and don't require painting.

Composite Timber-Aluminium

Composite frames combine timber on the inside with aluminium protection on the exterior.

This provides the warmth and insulation benefits of timber while reducing ongoing maintenance.

Fibreglass

Fibreglass frames are extremely stable and thermally efficient.

Although less common than other options, they offer excellent durability and work particularly well with larger glazing systems.

Other Window Features Worth Considering

Choosing your glazing and frame material is only part of the decision.

Several additional technologies can further improve window performance.

Low-E Glass

Low-emissivity (Low-E) glass includes a microscopic coating that reflects heat back towards its source.

This helps keep warmth inside during winter while reducing unwanted heat gain during summer.

Argon Gas

Many double and triple-glazed units contain argon gas between the panes instead of ordinary air.

Argon is denser than air, helping reduce heat transfer and improving insulation.

Warm Edge Spacers

The spacer separates the panes of glass around the edge of the window.

Modern warm-edge spacers reduce heat transfer around the perimeter of the glazing unit, helping improve overall performance and reduce condensation.

Will New Windows Stop Condensation?

Replacing old windows can make a significant difference, but windows alone won't eliminate condensation.

Moisture inside your home also comes from everyday activities such as:

Cooking
Showering
Drying clothes indoors
Breathing

Good insulation, effective ventilation and appropriate heating all work together to create a healthier indoor environment.

Which Windows Should You Choose?

There isn't one perfect answer for every home.

For many renovation projects, double glazing combined with thermally broken aluminium frames offers an excellent balance of comfort, durability and value.

If you're aiming for the highest levels of thermal performance, acoustic comfort or long-term energy efficiency, triple glazing may be worth considering.

The best choice depends on your home, your budget and your goals.

Planning a Renovation or Extension?

If replacing your windows is part of a larger renovation or extension, a little planning up-front can save time, money and unnecessary stress later on. Before you finalise your plans, read our guide Planning a Renovation in Wellington? Read This Before You Call a Builder, where we share practical advice on setting goals, understanding your options and preparing your project for success.

At Orkney Group, we help homeowners throughout the Wellington region make informed decisions that suit both their homes and their budgets.

If you're planning a renovation, extension or new build, we'd be happy to discuss the options and help you choose the right windows for your project.

Contact Orkney Group to start the conversation.