uPVC Casement Windows

Arguably the prettiest, most secure, most energy efficient uPVC casement window you’ll find.

Traditional or contemporary

Stylish and secure

Our classic Casement windows will suit any property style.

Our extensive range includes both sculptured and bevelled frames along with Firmseal’s exclusive Slimline System.
Security, heat loss and sound insulation are key features on all of our Casement windows, ensuring your home will be safer, warmer and quieter with Firmseal.
The range can be adapted for a traditional or more contemporary look – whichever you prefer.
Match the colours and style of your home

Imagine the difference you’ll see with new windows that perfectly match the colours and style of your beautiful home.

The Firmseal team is experienced and trained to install to a high standard and only use the highest quality materials to ensure your casement windows achieve thermal efficiency, long lasting durability and are finished to a superior standard.

The Firmseal process

We pride ourselves on offering the very best experience for our customers throughout every stage of the process.
Known fondly as the “Firmseal experience".

From quote to installation, we make it easy for you!

"We had dealt with Firmseal in the past. Came over and looked at showroom, was impressed, staff so helpful, everything went smoothly from start to finish. So nice to get to speak to a person at the end of the phone. Thank you to everyone."

Mrs M – Windows, Yeovil








What our customers say

Don’t just take our word for it. Hear what our customers have to say!

Excellent product & better value for money than competitor brands. Customer service has also been very impressive. We love our new windows.

Mr & Mrs T

Alitherm, Yeovil

Completely satisfied, you came recommended by my sister who has had various work done by yourselves.

Mrs C

Back Door, Yeovil