Products for a healthier home

Insulglaze - Retro-fit Double Glazing (Secondary Glazing)

Insulglaze is an innovative and stylish, retro-fit, secondary double glazing system manufactured from optical-grade acrylic and uPVC extrusion. The optical-grade acrylic used is 3% clearer than glass and does not distort, yellow or craze. One of the most appealing advantages of Insulglaze is that it can insulate both the existing glass and frames. Insulglaze provides all the standard benefits of double glazing but is up to 15 times stronger than standard glass and doesn’t shatter in the same way.

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How it works

  • 50% the weight of glass
  • Up to 11 times more break-resistant than glass

Insulglaze retains the character look of feature windows like leadlights and stained glass, and requires no change to the structural integrity of window frames, making it ideal for historic homes and villas. 

Furthermore, because Insulglaze retains your existing windows, which would otherwise go to landfills, it is kinder to the environment and a more cost-effective solution.



Ray & Jan Powell

We initially installed retro fitting (double glazing) into one bedroom on the south side bedroom. This has worked perfectly with minimal moisture now collected, no mold and a considerable reductions in noise since being fitted. This has encouraged us to refit another two rooms (which are currently being measured and fitted). We will be refitting the rest of the house next year.

We have found Emma and the installing team to be very professional and there installation was to a very high standard. All timelines were met and the final costs negotiated were reasonable and affordable – especially knowing what the cost of replacing windows would have been a much greater cost. The final look is appealing and looks no different to actual double glazed windows with the same effect – especially moisture reductions and installation.


David Nelson

When we touched the glass of the windows that had not been done on a cold morning the temperature difference was incredible, and there was zero condensation on the windows that were done. The windows that hadn’t been done were so wet we needed to use a shower scraper to wipe the windows.

Guy Paterson

 The HRV team have over the last 3 years retro fitted internal double glazing to all of our wooden window frames of our Craig CraigMoller two story home. The outcome has made a huge difference to coping with the Hutt Valley Winter. Alex and his team have made the process as affordable as possible without compromising the products quality.

Tony Van de Lem

 Very happy with the improved thermals in the house since the HRV Windows were fitted. Unreservedly recommend this product, we are very pleased with it

Tina Woods

Andrew and his team took great care and attention when installing our HRV Windows. The colourmatches and fitting left our windows looking original and keeping their ‘old world’ charm. We were very pleased with how they look now and we are enjoying a quieter and warmer home already. I would like to thank Andrew and the HRV team for their professionalism, courtesy and helpful attitude with this project. I would highly recommend them!