Rather than replacing existing windows, plastic secondary glazing adds an extra layer of insulation. This is ideal for historic buildings, where it may be difficult to install new double or triple glazing due to planning and conservation reasons. Adding an additional pane of clear Perspex acrylic (aka plexiglass) to the interior side of your existing window helps to stop valuable heat from escaping and makes a significant difference to comfort levels and energy bills.

In addition to being more cost-effective and easier to work with than glass, acrylic is also virtually unbreakable. This means you can keep your existing windows for as long as possible and it’s also a great choice for areas where the window is likely to be exposed to extreme weather conditions.

Plastic Secondary Glazing: Affordable Innovation for Enhanced Comfort and Insulation

There are many different forms of plastic secondary glazing available, from DIY sheets with magnetic strips to pre-made systems that are screwed into place. Some are designed to be used temporarily and can be removed in the summer, others are intended to be a permanent fixture that is left up all year round.

The most common and efficient form of plastic secondary glazing is a magnet-strip system, which uses clear acrylic sheeting. The breathable gap between the two panes slows down thermal transfer and allows air to circulate, further reducing heat loss. In our tests, this has proved to be a significant improvement over single-glazed windows in terms of retaining heat and preventing drafts.