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Finally…A Quick & Easy Way To
Double Glaze Existing Timber Windows

(Without Blowing The Budget)

We’ll show you how you can achieve the same benefits of new double glazed windows at a better price point.

Are you sick of windows that let outside noise in?

Fed up with poorly insulated single glazed windows?

And looking for the most effective way to double glaze your windows?

Soundproofing, insulating and retaining the character of your timber windows…is much easier and more cost-effective than you think.

About Thermawood Auckland

Welcome to Thermawood Auckland, your trusted partner in retrofit double glazing for timber joinery. We are a dedicated team of experts passionate about enhancing the comfort, energy efficiency, and aesthetics of your home through our innovative window solutions.

Our Mission

At Thermawood Auckland, our mission is simple, to transform your living spaces into warm and quite havens. We understand the importance of creating an environment that is not only visually appealing but also energy-efficient. With our retrofit double glazing technology, we strive to make your home more comfortable

What Sets Us Apart

  1. Experience: With years of experience in the industry, we have mastered the art of retrofit double glazing, especially for timber joinery. Our expertise allows us to deliver results that exceed your expectations.
  2. Thermawood System: Our patented dry glazed system will ensure your original timber windows will be preserved for the future and retain their heritage look.
  3. Quality Craftsmanship: Our team comprises skilled craftsmen who take pride in their work. We use premium materials and techniques to ensure the highest quality finish for your windows.
  4. Energy Efficiency: We are dedicated to reducing your carbon footprint. Our double glazing solutions not only improve insulation but also help you conserve energy and reduce your environmental impact.
  5. Personalized Service: We understand that every home is unique. Our team works closely with you to tailor our solutions to your specific needs, ensuring that your vision becomes a reality.

Why Thermawood?


Improve insulation by as much as 73%


Reduce noise by as much as 70%


Lower energy consumption by as much as 61%


Achieve all the same benefits of new double glazed windows and more


Costs about ⅓ of the price of new double glazed windows


Double glazing that lasts longer!

How Thermawood Can SAVE YOU THOUSANDS Of Dollars?

Ripping out your window frames and installing new double glazed windows is like undergoing unnecessary surgery on your existing windows.

It’s more expensive, riskier and more intensive and doesn’t always achieve ideal results.

Whereas the patented Thermawood process is compared to a non-invasive, in-patient procedure.

These are just some of the Thermawood installation advantages that save you tens of thousands of dollars:

Less downtime– installing a retrofit double glazing system takes only a few hours. The installation process is seamless compared to a new window installation, but you still get all the benefits and more.

There’s less risk– because only the single pane of glass is removed and there’s no risk of structural damage to your home.

It’s more efficient– with Thermawood, window technology today is more advanced, meaning there’s no longer a need to rip out your existing timber windows just to enhance the performance.

WARNING! What Most In The Industry Don’t Want You To Know

No matter what you or your window company does, water is going to get inside your windows. Especially with timber windows, any amount of moisture is too much.

Water won’t just rot timber; it will also cause the double glazed unit itself to fail.

What often happens is, window installers put the double glazed unit into a square rebate.

Then, they seal the window, usually with a commonly used silicone sealant.

At first, the unit is tightly sealed and your timber joinery looks safe from damage.

But unfortunately, this isn’t the case.

Over time, the problems begin to manifest, and water becomes trapped…

And because the double glazed unit is sitting in a square rebate, it is vulnerable to moisture pooling in the rebate.

Water vapour then begins rotting the timber and saturating the seal.

The moisture pulls contaminants out of the silicone sealant which results in water that is concentrated with dirt and contaminants.

This slowly deteriorates the polysulphide seal of the double glazed unit…

And once the seal becomes damaged, moisture and air get into the double glazed unit and you end up with that misty look on the inside of the glass.

How Thermawood Overcomes These Major Industry Issues?

Our entire process is designed around longevity…

With decades of knowledge, research and development as leaders within the industry we overcome these major issues in three ways…

Rebate With A 15-Degree Slope

We don’t stick your double glazed unit into a square rebate and seal it all the way around – trapping it with the very thing that will destroy it. Instead of a square rebate, we use special tooling to create a 15-degree slope underneath the double glazed unit.


Patented Drainage System

If moisture gets in, it has to get out! We use a unique drainage system, where every 100 millimetres there is a drainage slot. This enables any moisture to drain out underneath the timber bead and your double glazing so it lasts decades longer.


Unique Dry Glazing System

Instead of exposing your double glazing to silicone sealant or other similar wet sealing techniques that react with moisture by eating away at the double glazing, we use solid silicone blocks to support the double glazing to form what is known as a dry glazing system.


Just How Energy Efficient Is Thermawood’s Retrofit Double Glazing?

In an independent energy efficiency case study performed by a Thermawood customer the total energy consumption of the home was reduced by 61%.

In the graph you can see how the total consumption of energy in a home that a Thermawood retrofit double glazed changed dramatically from 974kwh in May-August 2016 to 373kwh in May-August 2017 after the installation compared to the same period the year before when it was single glazed.

What makes this case study even more fascinating is…

  • The homeowner installed solar at the end of July 2016, took out all gas operated appliances which were the water heater, cooktop and ducted heating and replaced these with electrical equivalents.
  • Plus, he started working from home in 2017.

Even with the additional energy consumption from the appliances that were previously gas and the homeowner working from home, he reduced his total energy consumption by 61% with Thermawoods retrofit double glazing.

See What Our Happy Customers Have To Say

Before & After Retrofit Double Glazing Installations

Full length single glazing converted into double glazing.

Before: Single glazed awning window

After: Converted into a double glazed window with the addition of a flyscreen secure window winder.

Before: Single glazed leadlight casement window.

After: The original leadlight was removed, refurbished and incorporated into the double glazed unit before it was installed with the addition of a flyscreen and secure window winder.

Request Your FREE No-Obligation Assessment & Quote

We inspect and assess every window in your home discussing any concerns to provide an individual solution based on the requirements of each window, whether it be reducing…

  • Condensation
  • Fading (UV Elimination)
  • Outdoor Noise
  • Window Break-Ins (Improved Security)
  • Heat Loss In Winter
  • And more…

Our vast glass selection provides you with every possible solution and combination…including the ability to install flyscreens that let your windows function fully.

Heat Loss and Condensation

  • Low E (Low Emissivity) glass improves insulation
  • Argon is better than air for insulation
  • Argon and Low E can be combined for higher performance
  • Low E and Argon gas further reduce condensation
  • The better the insulation the more comfortable the environment
  • The better the insulation the less condensation will occur

Heat Gain

  • The lower the shading coefficient (SC) the lower the heat gain
  • Tinted glasses are better than clear glass
  • Insulating Glass Units help reduce heat gain
  • Low E glass can help reduce heat gain


  • The lower the visible light transmission (VLT) the lower the glare
  • Grey and bronze tints generally have lower light transmission
  • Blue and green tints generally have higher light transmission
  • Insulating Glass Units slightly reduce the light transmission
  • Reflective glasses can cause internal glare at night


  • The higher the UV elimination the lower the level of fading
  • The lower the visible light the lower the fading
  • The lower the heat gain the lower the fading
  • Laminated glass helps reduce fading
  • Tinted glass helps reduce fading


  • Thicker glass will help reduce noise
  • Laminated glass will help reduce noise
  • Insulating Glass Units will help reduce noise
  • Different glass thicknesses in an IGU will help reduce noise

Safety and Security

  • Toughened and Laminated glass are both Grade A Safety Glasses
  • An IGU can have one or both sides with Safety Glass depending on the impact location
  • Use Safety Glass for sloped and overhead glazing
  • Special Safety Glasses can provide levels of security

We’ll work with you to help you determine the best solution for your conversion so you’ll get the results you want…And we will price per room for added convenience!

Lending Options Available for Retrofit Double Glazing

Enhance your home’s energy efficiency through an array of home loans specifically designed for retrofit double glazing. Experience the advantages of double glazed windows accompanied by competitive interest rates and adaptable repayment plans.

With most banks you can enhance the energy efficiency and eco-friendliness of your home by topping up your Home Loan with a fixed rate of as low as 0% – 1% for a duration of 3 year and up to a maximum amount of $80,000*

*Speak to your bank about directly to learn more about their current offering.