Retrofit Double Glazing

For timber windows and doors

Retrofitting Double Glaze is an essential matter in the nowadays building and renovation in New Zealand. We are not the only ones to say it, the quote below is from SmartHomes, which is administered by the Ministry of Business, Innovation and Employment’s (MBIE) Building System Performance branch.

“Once you’ve insulated your ceiling, floors and walls, the next biggest culprits for heat loss are the windows and other glazing such as skylights and glass doors. Today most new houses and additions will require double glazing to comply with the New Zealand Building Code.”

“The investment will be worthwhile – a warmer, healthier, quieter home with lower power bills.”

Add value to your house by being sustainable

What is Retrofit Double Glazing?

It is the process of replacing your existing single glass pane with double glazed units, i.e. two glass window panes with sealed gas in between (argon). Argon is heavier than air and its thermal conductivity – how much heat it can transmit under a specified condition – is 28% lower than air. This means that argon acts as an extra layer of insulation, minimising your home’s heat loss while the extra glass pane helps blocking the sound, reducing the noise level from outside.

Types of Double Glazing


Two window glass panes with argon sealed between them

LOW E PLUS – LOW E MAX – LOW E Xcel – LOW E Xtreme

Low-E stands for “low emissivity” and it was created to minimise the amount of infrared and ultraviolet light that comes through the glass, without jeopardizing the amount of light that enters your home. Low-E glass windows have a microscopically thin coating that is transparent and reflects heat, helping the argon in the job of insulating the house.

The image below shows a comparison between the different types of double glazing.

Of course, given the financial element of any home improvement project is always a concern, you begin to wonder how much energy-efficient windows like these cost. While the initial investment in double glazed windows is a little higher than the regular single-pane option, the amount you’ll save on your heating and cooling bills over the course of their lifetime will more than make them worth your while. That’s not considering the environmental benefit, either. Decreasing your energy consumption will help reduce your carbon footprint.


Improve your energy consumption by saving heat.

Improve your home environment healthy by reducing risk of having mould.

Keep original character and aesthetics of your property.

Help New Zealand be more sustainable by reducing wood waste.

Considerably reduce noise levels.

How does it work?

  1. Contact us by phone or email to arrange a visit to your place.
  2. We will send you a quote with your requirements.
  3. If accepted, we arrange a second visit where we take off windows and plywood will be installed.
  4. Modify your existing timber sashes at our workshop, safer and quicker, hassle free.
  5. Sealed timber beads will replace old putty .
  6. Re install your windows

We also double glaze door panels, leadlight and a variety of windows. If you have any personal project just contact us, our experienced joiners would be happy to help you out.

We do not offer double glazing for aluminium windows.

Statesmen Door Double Glazing

Double Glazing Triple Casement Window 

Double Glazing of French Door

Here at No. 8 Building Recyclers we work hard to be sustainable.

We made it to the list of The 8 Best Home Builders in Wellington by Top Reviews

Why Choose Us

Our company achieves sustainability goals through the use of recycled materials.

We have the best selection of recycled and restored doors, windows and floorboards.

We mainly work with native New Zealand timber, such as Rimu, Kauri and Matai.

Our carpenter has over 20 years experience.

Our items have been fairly obtained, mostly from demolitions, renovations and auctions.

Our prices are very competitive.

We are committed to the environment by segregating our recyclables.