General Questions

If you have timber windows, most likely yes!
We can retrofit almost all types of timber windows including Double Hung, Awning, Casement, Fixed, Clerestory, Doors, and Sliding Windows.
If you are unsure, send us a photo of your window and we'll check it out.

Double glazing retrofit can help you reduce energy costs, increase comfort, and improve the soundproofing of your property. It also enhances the appearance and value of your property.
It is significantly cheaper than replacing the whole window frame with a new uPVC, Timber or Thermally broken aluminium, but maintains similar performance.
It is also more sustainable, as you are not creating waste by discarding the existing frame.

No, you do not need to replace your existing frames during the retrofit process. Our team will install the new glass pane to your existing window frame.

Yes, double glazing retrofit is a long-term investment that can save you money on energy costs, increase the comfort and value of your property, and improve its sound insulation for many years to come.

Yes, double glazing retrofit is an environmentally friendly solution as it helps reduce energy consumption, thus reducing your carbon footprint.
As we retain your existing window frames, we reduce waste but not discarding frames like some other solutions.

The Government YourHome website has some great information on glazing to get you up to speed:

Double Glazing

Double glazing refers to a type of window construction in which two panes of glass are separated by a sealed air space. The air space provides an extra layer of insulation, reducing heat transfer through the window and improving energy efficiency. Double glazing also helps reduce noise levels and enhance the appearance of the window. The sealed air space can also be filled with an insulating gas, such as argon, to further improve the window's insulation properties.

Double glazing acts as a barrier, trapping air between the two glass panels, which acts as insulation, reducing heat transfer through the window. This helps regulate the temperature inside your home or business, making it more comfortable and reducing your reliance on heating and cooling systems.

A low-e coating is a microscopically thin, invisible layer of metal applied to the surface of a glass panel in double glazing. It reflects heat back into the room in winter and blocks heat from entering the room in summer, helping regulate the temperature inside your home or business.

No, the low-e coating is microscopically thin and invisible, making it an unobtrusive solution for improving energy efficiency.

We use a range of thicknesses, depending on window location, size and purpose.

Most common is 4mm thick glass, but we also use 5, 6, 8 and 10mm glass along with 6.5 and 6.9mm laminated glass.

The width of the air gap in double glazing windows can have a significant effect on the insulation properties of the window. Generally, the wider the air gap, the better the insulation performance, as there is more space for the insulation to work.

However, it is important to note that too wide an air gap can reduce the effectiveness of the insulation, as air can circulate within the gap and reduce the insulating properties. In addition, an air gap that is too wide can also result in condensation buildup between the panes of glass, which can impact the appearance of the window and potentially cause damage to the frames and seals.

It is generally recommended to use an air gap width between 6mm and 16mm for optimal insulation performance. The exact width will depend on the specific requirements of your double glazing project, including the size and type of the window, the climate, and the desired insulation performance.

We commonly use 12mm, with 8 and 10mm in some opening windows where required.

Double glazing windows are constructed with two panes of glass separated by a sealed air space. Here are the steps for the construction of a typical double glazing window:

  1. Measurement: The first step is to take accurate measurements of the window opening to ensure that the double glazing unit fits perfectly.
  2. Glass selection: The next step is to choose the type of glass to be used for the double glazing unit. There are different types of glass available, including clear, low-e, and toughened glass, each with its own unique properties and benefits.
  3. Cutting: The glass panes are then cut to size and beveled to fit into the window frame.
  4. Sealing: The two glass panes are then placed into a frame and sealed along the edges to create an airtight space between the panes.
  5. Air space: The air space between the two glass panes can be filled with air or an insulating gas, such as argon, to improve the insulation performance of the window.
  6. Spacer: The edges of the glass panes are sealed to a spacer, which acts as a barrier to prevent air from circulating within the air space.
  7. Drying: The unit is then dried to remove any moisture or air from the air space, to ensure that the unit remains airtight. A desiccant is placed within the spacer to absorb any residual moisture.
  8. Installation: The double glazing unit is then installed into the window opening, either as a retrofit or as part of a new window construction project.

This is a basic overview of the construction of double glazing windows. The exact process and materials used may vary depending on the specific requirements of the project and the manufacturer.


For most windows, around 1.5-3hrs per pane of glass.
This includes removing the old glass and beading, prepping and routing the frame, installing and sealing the new double glazed unit and finally adding new beading or capping.
Double Hung (sash) windows can take considerably longer, as can anything that needs repair or has 'glazing cement' holding the windows in.

We usually have a 2-4 week lead time once we have completed the measure and you have accepted the quote.

Not really!
You may see a little bit of the black spacer around the edge of the frame, depending on your window.
Other than that, your windows will look the same as they always have.

Yes. As we leave your frames intact, your flyscreens will also still work. Some may need to be moved slightly if you opt for additional seals on the inside of the windows.

For double glazed units, there are a few minimum. The minimum chargeable size is 0.4sqm, so anything smaller than that will be charged at 0.4sqm.
For bigger units, you may need to step up from 4mm glass to 5mm glass or more, this is generally anything over 2400 x 1200mm.
Some areas also require 5mm glass for BAL ratings (Bushfire Attack Level).

There is a cost to get glass to our factory for pickup, or to your site for install.
These rates are a flat rate, so are the same for 1 piece of glass or 100!

If we are doing the install for you - nothing! We will bring all we need.
If you are DIY, in addition to the glass you will need:
- Beading and/or capping. This is timber to finish the frame and seal against the glass.
- Silicon - this must be a 'neutral cure' silicon to avoid damaging the IGU seals
- Nails - ideally with a nail gun for ease of install and reduced chance of breakage
- Spacer blocks - these sit under the glass