Paul Mason of Sound Proof Glazing installed secondary glazing in our apartment in 2016, so we have the benefit of 2 years of experience with the product. The additional layer of glazing has made a tremendous difference to heat retention in the colder months – we are able to maintain a comfortable temperature in the unit far more easily than before. Sound reduction is also excellent – the noise from passing garbage trucks, the neighbours hedge trimmers/blowers etc has gone from being a nuisance to being virtually non-existent. The new window frames were colour matched to our existing windows, and they were very thin, so the new system is hardly noticeable. Paul’s quote was competitive; he was very careful in his measuring up and subsequent installation; and his after-sales service is exemplary. Highly recommended.