A Traditional PVC-U Sash Window System for Heritage and Period-Style Applications

The Vertical Sliding Sash Window is a high-performance PVC-U system designed to replicate the appearance of traditional timber box sash windows. Combining authentic period detailing with modern performance, it is ideal for use in heritage-sensitive areas, conservation zones, and traditional-style new-build developments.

Manufactured by Epwin Window Systems, this window system delivers excellent thermal efficiency, security, and ease of maintenance—making it a reliable solution for both refurbishment and new construction projects.

Design & Aesthetic Excellence

The Vertical Sliding Sash Window has been developed to closely mirror the proportions and features of classic timber sash windows. It includes a range of authentic design options to meet planning requirements and aesthetic expectations.

Traditional ovolo detailing and deep bottom rail
Optional run-through sash horns and Georgian or astragal bars
Mechanically jointed or welded frame options
Slim sightlines for enhanced visual appeal
Available in over 30 colour options including woodgrain finishes
Dual-colour options for internal/external contrast
Tilt-in facility for safe internal cleaning
Slim meeting rail option

This attention to detail ensures suitability for conservation areas and heritage projects, while also enhancing the character of new-build homes.

Thermal Performance & Energy Efficiency

The system is designed to meet modern energy efficiency standards while maintaining traditional aesthetics. Its multi-chambered PVC-U profiles and advanced glazing options help reduce heat loss and improve occupant comfort.

U-values as low as 1.3 W/m²K
Multi-chambered profiles for improved insulation
Glazing options: 24 mm double glazing or 36 mm triple glazing
Optional recycled composite thermal inserts
Co-extruded gaskets for airtightness
Supports compliance with Approved Document L

These features contribute to reduced energy consumption and long-term sustainability.

Security & Compliance

The Vertical Sliding Sash Window is engineered to meet modern security standards while maintaining traditional styling. It is suitable for use in residential and public sector buildings where safety is a priority.

PAS 24:2022 certified
Secured by Design compliant
Internally glazed for added security
Optional restrictors for safe operation
Compliant with Approved Documents Q (Security), L (Thermal), and M (Access)

This ensures the system meets the demands of current UK Building Regulations.

Durability & Low Maintenance

Manufactured from high-quality, lead-free PVC-U, the Vertical Sliding Sash Window offers long-term durability with minimal maintenance. Unlike timber, it does not require painting or regular upkeep.

Weather-resistant and UV-stable
Easy to clean and maintain
Long service life with minimal upkeep
Backed by manufacturer warranties

This makes it ideal for social housing, rental properties, and heritage buildings where ongoing maintenance must be minimised.

Construction & Configuration

PVC-U vertical sliding sash window system
128 mm outer frame depth
Welded or mechanically jointed options
Tilt-in facility for safe internal cleaning
Optional run-through horns and deep bottom rails
Compatible with astragal bars and Georgian bar layouts
Internally glazed as standard

This flexible construction allows the system to be tailored to a wide range of project requirements.

Sustainability

The Vertical Sliding Sash Window supports sustainable construction through responsible sourcing, recyclability, and energy-efficient performance.

Recycled composite thermal inserts available
Fully recyclable PVC-U profiles
Manufactured in the UK to ISO 14001 environmental standards
Supports BREEAM and other sustainability targets

Its long lifespan and low environmental impact make it a responsible choice for traditional and modern developments alike.

Digital Specification Support

To support digital workflows and specification platforms, the Vertical Sliding Sash Window is available with:

NBS Chorus-compatible specification data
BIM object availability (Revit, IFC, DWG)
COBie-compliant data
Full technical documentation including datasheets, test reports, and installation guides

Why Specify the Vertical Sliding Sash Window?

Traditional sash styling with ovolo detailing and deep bottom rails
U-values as low as 1.3 W/m²K
PAS 24 and Secured by Design compliant
Tilt-in facility for safe internal cleaning
Wide range of colours and finishes
Durable, low-maintenance PVC-U construction
Suitable for conservation areas and heritage projects
Backed by Epwin’s technical support and warranties