APA 70 Hidden Sash Window System
The APA 70 Hidden Sash Window System combines minimalist design with outstanding thermal and acoustic performance — perfect for homeowners who value contemporary aesthetics and comfort in equal measure.
This innovative system conceals the sash behind the outer frame, creating an elegant, slim-profile look that maximises natural light and delivers a seamless exterior appearance. From the inside, the clean lines and flush finish complement any interior style, making it ideal for modern homes, extensions, or high-end refurbishments.
Engineered from thermally broken aluminium with advanced insulation technology, the system achieves exceptional energy efficiency and acoustic comfort. Double or triple glazing options ensure year-round performance — keeping your home warm, quiet, and secure in every season.
Built with APA’s focus on durability and sustainability, the 70 Hidden Sash window offers long-lasting performance with minimal maintenance, providing a perfect blend of design sophistication and practical efficiency for contemporary residential living
For more information regarding our APA 70 Hidden Sash Window System range, get in touch with us here.
- Frame depth: 70 mm thermally broken aluminium system
- Hidden sash design – sash completely concealed behind the outer frame for minimal sightlines
- Visible section: 66 mm (frame + sash combination)
- Thermal insulation: Polyamide thermal break system with high-density insulation rods
- Finishes: Single or dual-colour powder coating with over 200 RAL colours available in single or dual finish
- Glazing options: Double or triple glazing up to 40 mm thickness
- Air permeability: Class 4 (EN 12207) Water tightness: Class E1200 (EN 12208) Wind resistance: Class C5 (EN 12210)
- Acoustic performance: Up to 46 dB (depending on glass type)
- Opening possibilities: Side hung, top hung, tilt & turn, fixed light, or combination units
- Hardware: Multi-point locking system for enhanced security
- Can be pre-assembled in-house saving installation time/cost
- Matching rebate doors available
- Identical sight lines throughout
- Includes multi-point locking for added security
| Thermal transmittance | Uw ≥ 0,84 (W/m²K) | |
| Acoustic insulation | Rw up to 46 dB | |
| Air permeability | Class 4 | |
| Water tightness | Class 1800 | |
| Wind resistance | Class C5 | |
| PAS24 security test | Approved | |
| Sections | Frame 70 mm, Sash 70 mm | |
| Polyamide bar length | 35 mm | |
| Profile thickness | Window 1.9 mm | |
| Glazing | Max. 40 mm, Min. 26 mm | |
| Maximum sash weight | 160 kg |
*Whole window U values are a combination of the frame and glazing thermal performance and as such will vary with the specification of glass utilised. Please consult with the APA technical team for more specific performance information.
