The Firmseal Experience

Since its birth way back in 1988 we have grown into the areas largest independent home enhancement companies.

over the years we have earned an “envied” reputation for delivering an exceptional customer experience to more than 30,000 very happy local home owners.

Our constant year-on-year growth has benefitted us in many ways, apart from allowing us access to market leading, innovative products and preferential treatment from our suppliers, we have been able to acquire and to integrate two smaller but no less successful companies into The Thermaglaze Family.

Recent years have seen the acquisition of Clearglaze Windows of Bath est 1980 and Firmseal of Yeovil est 1988, this expansion extended our reach across the areas of Yeovil & Bath thus inviting many more customers to enjoy ‘The Thermaglaze Experience’.

Our ethos is a simple one!

To exceed our customers’ expectations by delivering lasting value, exceptional standards & an unrivalled service second to none every time. Thus being the first name considered when enhance their homes and thus becoming their supplier of choice.

The Firmseal Family

Thermaglaze is the mother ship of three local home enhancement companies, all offering the same excellent service, and good old fashioned value for money to discerning local home owners looking for the very best windows, doors & conservatories, that will be installed with love.


Firmseal Windows was Born in 1988 and built it’s enviable reputation in Yeovil and the surrounding areas by providing a higher quality range of products, customer focused service, superior installation standards, all at a very competitive price.

In 2012 Paul, its founder was approached by Thermaglaze of Wiltshire who had also earned an enviable reputation in its own area because of its equal ethos of ‘giving double glazing a good name’.

So Paul/Firmseal decided it was a great, beneficial idea to become part of the Thermaglaze Family thus opening more doors (no pun intended!) to its customers by adding additional products, services and a joint expertise that it now has to offer discerning, local home owners.