We are a bit biased here at Podocarp in regards to our love for timber joinery, but this is not without evaluated reason (for those of you who need a bit more evidence based than our passion alone). 

In this blog we wanted to talk more about wooden or timber windows and the thermal advantages when double glazed. We approach this topic each Autumn as we find we get an influx of enquiries as the colder seasons start to creep in again and the reality of single glazing or poor fitting joinery returns; condensation, damp windows and colder homes.

There is a myth regarding wooden window sashes. People often think they are the cause of many heating problems within a home. This in fact is not true. Yes, poorly maintained windows or mal fitting windows and damage does not help, but this deterioration happens over a long period of time. If windows are maintained (as everything needs to be in one way or another) timber windows are actually the complete opposite; not only aesthetically appealing but also the most thermally advantageous material to surround your double glazing. We will explain why.

Wooden windows add warmth, charm, and a natural aesthetic to any home. They provide a classic, timeless look that can enhance the overall appearance of both the interior and exterior of a house.

Some facts about wood and its benefits for using for window joinery:

• Wood is a natural insulator and therefore energy efficient, providing excellent thermal performance.

• High-quality wooden windows are also durable; when properly maintained, can last for decades.

• Wood is a sturdy material that can withstand different weather conditions, especially if it's treated and sealed correctly. Ideal for a small island such as New Zealand and our climatic conditions.

• Wood is a renewable resource, therefore environmentally friendly. Wooden windows can be recycled and repurposed, further reducing their environmental impact. 

• Unlike some other window materials, wooden windows are relatively easy to repair. This is something we specialise in at Podocarp and encompass this as part of our retro-fit service if needed. 

• Wood also has natural sound-dampening properties, which can help reduce noise transmission from outside, providing a quieter and more peaceful indoor environment. 

So onto the more technical terms and thermal properties of timber;

Wood is a natural insulator, meaning it has the ability to resist the flow of heat. This property helps wooden joinery maintain indoor temperatures by reducing heat transfer between the interior and exterior of a building.

There are several measures you will see associated with thermal measurement in glazing systems;

• The U-factor, also known as thermal transmittance, measures the rate of heat transfer through a material. Lower U-factor values indicate better insulation properties. Wooden joinery typically has a relatively low U-factor compared to materials like aluminum, which is a good indicator of its thermal efficiency.

• You will also see reference to the R-value in some text, this typically refers to the thermal resistance of a window or glazing system. The R-value measures how well the window or glazing material resists the flow of heat through it. A higher R-value indicates greater thermal resistance, meaning the window is better at insulating against heat transfer. For instance Low-E with Argon glazing has a higher R value than standard double glazing.

• Wooden joinery also has a natural ability to resist condensation, which occurs when warm, moist air comes into contact with a cooler surface.

So what is retro-fit double glazing?

Retrofit double glazing of timber joinery offers a cost-effective way to upgrade existing windows or doors without the need for complete replacement. The single panes are removed and replaced with new insulated double glazed units. It can significantly improve the energy efficiency and comfort of a home or building while preserving the aesthetic appeal of the original timber frames. You can learn more about the actual process here.

We wrote a previous blog regarding retro-fit glazing and financial options out there that can be used for this process. Jump over to it here.