Secondary Glazing in Housing and Its Improvements

What is Secondary Glazing?

Posted: Monday, 30 June 2025

We describe Flutter Shutter as a fabric first energy efficient measure, interchangeable with calling it energy efficient secondary glazing. But many might not be aware of what secondary glazing actually entails.

Throughout this blog, we aim to highlight this technology and its potential to enhance the overall energy efficiency of a home.

What Does Secondary Glazing Refer to?

Secondary glazing involves adding an additional layer of insulation and glazing on the interior side of existing windows in a building. This helps to create a barrier of insulating air within the window cavity. This, in turn, reduces the amount of thermal energy escaping through the windows over time.

There is a large range of window systems that can fulfil this role. For instance, plantation shutters, heavy curtains, and a roller blind. Each of these provides an additional barrier to the heat that naturally wants to escape from the home into the wider environment.

How Does Energy Efficient Secondary Glazing Work?

With, for instance, energy efficient plantation shutters, the trapped layer of air between the barrier and the window helps to insulate the building more effectively. Reducing draft and thermal bleed while plugging gaps.

Improved Insulation

The main benefit of secondary glazing techniques is, of course, the energy-saving effect. Energy efficient secondary glazing can significantly reduce a home’s energy usage. Reducing the amount of gas/electricity needed to maintain a comfortable temperature.

Thereby saving on the monthly bills of the structure. Moreover, as it is overall cheaper than other methods of insulation, it can provide efficiency improvements without incurring costly installation fees.

Low-Cost Alternative

Compared to the removal of old windows to install double-glazed windows, secondary glazing measures are far, far more cost-effective. And more than just the cost of the energy efficient plantation shutters themselves, there are the costs saved on other measures.

Ageing boilers or other heating systems can be sustained for longer by making the home more energy efficient. Avoiding the need to replace them for potentially years.

On a cost basis, energy efficient secondary glazing measures are far cheaper than installing other options.

And not to forget, they are also more easily adjusted.

Adjustable Heat Retention

A fabric first energy efficient measure, such as Flutter Shutter, has the benefit of being more flexible than other secondary glazing options. Or other heat retention methods in general.

This is because the blind and plantation shutters can be adjusted on the fly. In hotter months, they can be adjusted to allow more heat to escape from the home. Preventing overheating while maximising the heat available during the colder months.

Suited to Listed Properties

When it comes to historic buildings or listed properties, the normal invasive solutions to improving energy efficiency can take months of approval. Or they may not be approved at all.

This is where secondary glazing measures, such as Flutter Shutter, can come in. This is because a fabric first energy efficiency measure is non-invasive and doesn’t require extensive work to install. The plantation shutters and blinds can be easily installed without causing extensive damage to the surrounding structure.

Which would be true in the case of double or triple glazing.

In Need of Your Own Energy Efficient Secondary Glazing Installation?

If you want to improve your home’s energy efficiency, get in touch!

Our fabric first energy efficient measure acts as the perfect secondary glazing measure, improving the thermal envelope of any building, especially those within the UK’s social housing stock.

If you would like to discuss your installation, you can contact us through our website form, by phone at 01512454691 or through email at contact@fluttershutter.org today.