Double-glazed flush sash windows offer enhanced insulation and security compared to standard windows
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Consider upgrading your home with double-glazed, flush sash replacement windows from Glevum. Enhance both appearance and security. Explore their key advantages below.
Smart as Standard: These windows include Kubu® Smart Security Sensors. The Kubu® Smart Alerting System lets you check whether your window is open, closed, or being tampered with via a smartphone app. T&Cs apply.
When picturing new windows, many think of the bulky frames common for decades. But what if you could get modern warmth and security without sacrificing your home’s style? This is where flush windows change the game. The name describes the design perfectly: the window’s opening section sits completely level with the frame, creating one flat, seamless surface. This clean profile offers a high-end alternative to the overlapping look of standard windows, creating a tighter seal for better warmth and security.
- Modern, clean appearance.
- Slim sight lines for enhanced views.
- Complement both traditional and contemporary homes.
- Exceptional energy efficiency.
- Strong weather protection.
- Excellent value for money.
This window range has achieved a top-tier BFRC energy rating of A++ for select configurations, with other options rated A+.
With over 40 years of experience and a strong reputation in Gloucestershire, Glevum ensures a smooth window replacement process. Our windows include a 10-year insurance-backed guarantee for quality and durability. Financing is available, allowing you to upgrade to energy-efficient windows without delay. To get started, book a free home visit and discover why many homeowners choose Glevum.
Frequently Asked Questions:
Looking for replacement flush sash windows in Cheltenham, Gloucester, Hereford or Monmouth? Then here’s why you can feel good about working with Glevum:
- Established in 1984, we offer extensive knowledge and experience.
- We are a leading FENSA-approved window and door installer based in Gloucestershire.
- We are a Kubu Pro Installer.
- All our windows and doors include a 10-year GGFi-backed guarantee.
- Our dedicated Service Department is here to support you.
- More than 45,000 customers enjoy the security and quality of our windows and doors.
- About half of our work comes from returning customers and recommendations.
- We offer a range of Finance Options. Just ask for details during your free home visit or quote.
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“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
“Very professional service from the quote to the fitting. Very pleased.”
J Ochiltree (Gloucestershire)
January 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 service and workmanship. Highly recommend."
M Tomlin (Gloucestershire)
November 2025
"Glevum were very professional throughout the purchase and installation and I am happy with the finished result. Installation team were courteous, neat and tidy throughout the process."
R Elliott (Gloucestershire)
November 2025
“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
“Very professional service from the quote to the fitting. Very pleased.”
J Ochiltree (Gloucestershire)
January 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 service and workmanship. Highly recommend."
M Tomlin (Gloucestershire)
November 2025
"Glevum were very professional throughout the purchase and installation and I am happy with the finished result. Installation team were courteous, neat and tidy throughout the process."
R Elliott (Gloucestershire)
November 2025