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Quick Product Snapshot
Key Information at a Glance
Opening Style
Outward side-hung opening
Frame Material
Timber or aluminium-clad timber, depending on chosen Rationel range
Best Suited For
Bedrooms, living spaces, traditional homes, renovations and new builds
Glazing Options
Double or triple glazing with acoustic, solar-control, safety, security and privacy glass options
Energy Performance
Triple-glazed Rationel AURA/AURAPLUS options can achieve strong U-values and acoustic performance depending on configuration
Security
Security hardware and Rationel SECURE glass options available, with Secured by Design specification possible where appropriate
Warranty
Rationel timber/aluminium windows are typically covered by a 10-year warranty; timber windows by 5 years, subject to product range and terms
Design & Options
Rationel windows are made bespoke, so the design can be built around the property rather than limited to a standard size or finish. The main choices are whether to use all-timber or aluminium-clad timber, which opening function suits the room, and which glass specification is needed for comfort, privacy, security and acoustic control.
✓ Choose timber for a natural finish, or aluminium-clad timber for a lower-maintenance exterior.
✓ More than 200 colour choices are available, with different internal and external colours possible on suitable ranges.
✓ Glazing options include SOUND, SOLAR, OBSCURE, safety, security, patterned and coloured glass.
✓ Double or triple glazing can be selected depending on thermal, acoustic and project requirements.
✓ Opening functions can be matched across the home, including side-hung, top-guided, side-guided, tilt-turn, fixed and shaped units.
Why choose RATIONEL Side Hung Windows
Side hung windows are one of the most familiar and versatile window styles, and Rationel’s version brings a much more premium feel than standard uPVC. They work across both contemporary and traditional homes, with timber frames for warmth and aluminium-clad options for lower maintenance and long-term durability.
Key Features
Classic outward opening
for timeless everyday use
Warm timber interior
for a natural interior feel
Alu-clad option available
for reduced maintenance
Strong glazing choices
for tailored performance
Performance & Comfort
With carefully engineered timber frames and advanced glass options, Rationel side hung windows provide excellent comfort, security and acoustic control. Aluminium-clad versions add a robust external finish, reducing maintenance while preserving the quality feel of timber inside.
Energy Efficient
Triple-glazed ranges achieve U-values from 0.78 W/m²K.
Enhanced Security
Security hardware meets Secured by Design requirements.
Weather Resistance
Low-maintenance alu-clad option with 40-year life expectancy.
Acoustic Comfort
Triple glazing gives up to 42–43 dB Rw sound reduction.
Are RATIONEL side hung windows right for your property?
Rationel side hung windows suit homeowners who want a classic outward-opening window but with a more premium feel than standard casement replacements. They work across traditional homes, new builds and extensions, particularly where timber detail matters inside the room. Choose the aluminium-clad option where exposed elevations need extra durability and lower long-term maintenance without losing the quality of a timber interior.
HOME RENOVATIONS
NEW BUILDS
EXTENSIONS
CONVERSIONS
