Double-glazed flush sash windows provide better insulation and security than standard windows
Here to help
Thinking about improving your home? Glevum’s double-glazed, flush-sash replacement windows can boost both the appearance and security. Take a look at their main benefits below.
Smart as Standard: These windows come with Kubu® Smart Security Sensors. With the Kubu® Smart Alerting System, you can use a smartphone app to see whether your window is open or closed, or if someone is trying to tamper with it. T&Cs apply.
- They have a modern, clean look.
- These windows suit both traditional and modern homes.
- They are highly energy efficient.
- They offer strong protection against the weather.
- You get great value for your money.
What makes Glevum Windows a trustworthy choice for your replacement flush sash windows?
Out of 640 customers who took our Customer Survey, 92% said they would recommend Glevum Windows to others!
- We have been in business since 1984, bringing years of knowledge and experience to every project.
- We are a trusted FENSA-approved window and door installer based in Gloucestershire.
- We are an approved installer for Get Snug Windows & Doors.
- We are also a Kubu Pro Installer.
- All our windows and doors come with a 10-year INSTALLsure (formerly the GGFi) insurance-backed guarantee.
- If you need planning permission or building regulations, we will take care of it on your behalf.
- Our dedicated Service Department is always here to help you.
- Over 45,000 customers trust the security and quality of our windows and doors.
- Nearly half of our work comes from returning customers and referrals.
- Rated 'Excellent' on Trustpilot.
- We offer a range of Finance Options. Feel free to ask about them during your free home visit.
“Excellent. Turn key solution and Glevum took away my hassle, particularly that the location was not the easiest. Very good communication at all stages.”
M Julian-Jones (Newport)
September 2026
“Professional, timely, friendly and efficient.”
J Hardwick (Stonehouse)
August 2026
“A pleasure, as always. From start to finish, everything ran smoothly.”
G Delaney (Cheltenham)
July 2026
“Really lovely company. Have used in a previous home and would use again.”
S Price (Cheltenham)
June 2026
“Everyone we encountered from the company was very helpful, knowledgeable and friendly.”
G Day (Gloucester)
May 2026
“Really good, great throughout and great finished product.”
H Jenkins (Lydney)
April 2026
“Friendly, helpful staff from sales person to fitter, excellent service all round.”
J Holyhead (Gloucestershire)
March 2026
“Very helpful and reassuring. My window and door were fitted by 2 very nice men and its prefect, we are so pleased, thank you so much.”
K Smith (Gloucestershire)
February 2026
“We have used Glevum many times over the last 25 years and have never been disappointed with the quality of workmanship, timely service and friendly approachable people.”
M Tattersall (Gloucestershire)
January 2026
“Excellent. Turn key solution and Glevum took away my hassle, particularly that the location was not the easiest. Very good communication at all stages.”
M Julian-Jones (Newport)
September 2026
“Professional, timely, friendly and efficient.”
J Hardwick (Stonehouse)
August 2026
“A pleasure, as always. From start to finish, everything ran smoothly.”
G Delaney (Cheltenham)
July 2026
“Really lovely company. Have used in a previous home and would use again.”
S Price (Cheltenham)
June 2026
“Everyone we encountered from the company was very helpful, knowledgeable and friendly.”
G Day (Gloucester)
May 2026
“Really good, great throughout and great finished product.”
H Jenkins (Lydney)
April 2026
“Friendly, helpful staff from sales person to fitter, excellent service all round.”
J Holyhead (Gloucestershire)
March 2026
“Very helpful and reassuring. My window and door were fitted by 2 very nice men and its prefect, we are so pleased, thank you so much.”
K Smith (Gloucestershire)
February 2026
“We have used Glevum many times over the last 25 years and have never been disappointed with the quality of workmanship, timely service and friendly approachable people.”
M Tattersall (Gloucestershire)
January 2026
Frequently Asked Questions:
Areas We Serve:
Glevum Windows is a trusted home improvement specialist, helping homeowners throughout Gloucestershire, Herefordshire, Worcestershire and Monmouthshire.
We’re one of the largest, leading independent double glazing companies based in Gloucestershire. While our core area is Gloucestershire, we are ideally located to serve home improvement needs in Cheltenham, Gloucester, Tewkesbury, Stroud, Cirencester, Hereford, Ross-on-Wye, and Monmouth, among others.
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