Spring balance mechanism
Smooth, effortless vertical sliding with spring balance operation. No cords or weights to fail, and both sashes tilt inward for easy cleaning.
Windows
Sliding Sash Windows
Classic vertically sliding sashes with authentic period proportions, available in UPVC with spring-balance operation and tilt-clean functionality.
- 128mm frame depth
- Spring balance operation
- Inward tilt-clean function
- Child safety restrictors available
10YEARGUARANTEE
Assure certifiedNo subcontractorsFinance availablePersonalise Your Window
Colours & Finishes
Frame Colour: Smooth White
Standard colours
Extended lead time colours
Dual colour available, different interior and exterior finishes on request.
Hardware Finish: White
Handles, letterplates, and accessories available in matching finishes.
Made to measure. Confirm your colour and hardware choice during your free survey.
Free Survey
Ready to shortlist this product properly?
If this looks like the right fit, we can survey the opening, confirm the specification, and price it properly for your home with no obligation.
Free surveyFixed quoteDirect CII installation team
Vertical sliding sash windows are the defining feature of Victorian, Edwardian, and Georgian properties across Romford and Essex. CII Double Glazing supplies and installs uPVC vertical sliding sash windows with a deep 128mm frame that faithfully replicates the proportions of original timber box sashes. Spring-balance operation gives a smooth, effortless glide. Both sashes tilt inward for easy cleaning from inside. No ladders required. Our directly-employed team fits every window with no subcontractors involved.
Key Specifications
High security cam locks available
Child safety restrictors on bottom sash
Run-through sash horns available
Brushpile interlock for draught-free operation
Welded or mechanical joints
100% lead-free, recyclable uPVC
Engineering Detail
What makes our sliding sash windows different
Meeting rail detail
The interlocking meeting rail provides a weather-tight seal between upper and lower sashes, with brushpile interlock eliminating draughts.
Sash lock security
High security cam locks secure both sashes in the closed position with multi-point engagement for comprehensive resistance to forced entry.
Welded corner joints
Precision-welded corners give the 128mm frame structural rigidity that exceeds mechanical jointing, with no gaps or weak points at the corners.
How It Works
From Survey to Sign-off
Step 1
Survey
We visit, measure, and advise on the right configuration for your property.
Step 2
Install
Our directly employed team installs with clean, tidy workmanship.
Step 3
Sign-off
Final checks, handover, and Assure certification where required.
Next Step
Want a fixed quote from a real survey?
We will measure up, talk through finishes and installation details, and give you a clear quote based on the actual opening rather than a generic estimate.
Free surveyFixed quoteDirect CII installation team
Checkatrade
“Fantastic experience from initial survey to completion. The team were professional, tidy, and the attention to detail on the finish was fantastic. Couldn't be happier with our new windows.”
Checkatrade
“Used CII for our entire house of windows. Brilliant from start to finish. Knowledgeable, reliable, and very professional. The quality of the product and installation is second to none.”
Questions Answered
