Slim HD aluminium casement windows for larger openings
The Sieger HD Casement Window is a heavy-duty aluminium window system designed for projects that need larger opening sizes without losing the clean, square-edged appearance of a slim framed window.
With a thermally broken aluminium frame, PAS 24 security, full weather testing and a wide choice of configurations, the system is well suited to premium homes, modern extensions, replacement glazing, commercial projects and architect-led developments where scale, performance and design quality all matter.
Sieger Systems supplies and installs slim HD aluminium casement windows across London, Buckinghamshire, Berkshire, Oxfordshire, Hertfordshire, Surrey, Bath, Bristol and Somerset.
Premium performance
Bespoke made to order
Designed & made in the UK
PRODUCT FEATURES
Sieger HD casement window features
Larger window sizes
Designed for larger casement window openings while maintaining a slim, square-edged aluminium profile.
Flexible configurations
Top hung, side hung, fixed, bottom hung and tilt and turn options can be specified.
PAS 24 security
PAS 24 certification and multi-point locking support secure performance for homes and projects.
Over 200 RAL colours
Frames can be finished in over 200 RAL colours to suit the wider glazing package.
To learn more about additional features:
Technical performance
| Frame depth | 58mm / 70mm |
| Maximum sizes | Side hung: 900mm x 1800mm | Tilt and turn: 1400mm x 2400mm |
| Typical glass specification | 6mm glass / 16mm argon gas cavity / 6mm glass |
| Configurations | Top hung, side hung, fixed, bottom hung, tilt and turn and more |
| Security | PAS 24 certified with multi-point locking |
| Weather performance | Air Class 4, water 9A and wind 2400 Pa |
GLASS OPTIONS
- Double glazed units
- Argon gas filled glazing
- Low-E glass
- Solar control glass
- Acoustic glass options
- Laminated safety glass
- Switchable tinted glass
- Heated glass
Real projects
View our products in action.