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P31A/T Triple-Glazed Outward Open Alu-Clad Timber / Timber Only Window
Verified by manufacturer 15 hours ago
PAS 24
Certificate type
Composite window unit with aluminium cladding. Triple-glazed, outward opening window in a bespoke timber frame.
Application
Triple glazed, composite window unit suitable for modern or traditional low-energy and Passive House-standard homes, refurbishments, retrofits and new buildings - Build It's Window of the Year has been used on a wide array of project scopes and remains Norrsken's best-selling window.
Whether it's converting industrial barns into a contemporary sanctuary or pushing the boundaries of sustainable design in Passive House schools, our projects span every architectural vision.
We work with clients on a wide range of projects throughout England, Wales and parts of Scotland.
Description
This outward opening window unit is a triple-glazed, energy-efficient window combining the warmth of timber (P31T timber-only model) with optional durable aluminium cladding (P31A alu-clad model) . Suitable for Passive House and high-performance homes, it offers low maintenance, excellent thermal performance, and award-winning design.
Features and benefits:
- Triple-glazed 48 mm window unit with argon gas filling, warm edge spacer bar, and two panes of Low-E glass for exceptional thermal efficiency.
- Whole-window U-values around 0.75 W/m²K, suitable for extremely energy-efficient and Passive House homes.
- Outward opening design with optional aluminium cladding for superior weather protection and minimal maintenance.
- Engineered timber frame protected by technically advanced sprayed coatings for enhanced durability and a high-quality finish.
- Aluminium cladding is polyester powder coated for a long-lasting, low-maintenance exterior.
- Both aluminium and timber components available in a full range of RAL colours for complete design flexibility. Timber frame internally available in a range of natural stains to enhance the wood's natural warmth.
- Frame depths from 94 mm to 122 mm, with optional decorative moulding on deeper sections.
- Combines the natural warmth of timber with the resilience of aluminium.
- Award-winning design – 'Build It' named it Window of the Year 2023.
- Available in side hung, top hung, fixed frame and fully reversible opening configurations with concealed hinge system for sleek exterior appearance.
- Transoms, decorative glazing bars, bespoke shapes including curved glazing available.
- PAS 24 Certified.
Create Something Distinct
Beyond bespoke dimensions and precision manufacturing, we provide the design flexibility to perfectly express your vision.
From custom shapes and specialized hardware to powder-coated trims and distinct hardware - find the finishes you need, whatever your project specification.
Browse available Window Handles and more project inspiration for full customisation in your designs.
General information
Color | Beige Black Blue Bronze Brown Manufacturer guidanceBoth aluminium and timber components available in a full range of RAL colours for complete design flexibility. |
Finish | Powder-coated Textured |
Material | Wood Timber Aluminium |
Shape | Rectangle Square Circle Crescent Diamond |
Length | Bespoke |
Width | Bespoke |
Height | Bespoke |
Warranty description | Ten year |
Uniclass | |
CAWS | L10/33 Proprietary windows L1/102 Proprietary windows L10/400 Composite windows |
SKU Code | P31A |
Specification data - Composite window units
Classification data | |
Standard | To EN 14351-1. |
Third-party certification | PAS 24 and Environmental Product Declaration (EPD). |
Dimensions and configurations | Manufacturer guidanceOutward opening. Consult manufacturer for details and insert size requirements. |
Product performance | |
Weather performance | |
Air permeability | To EN 12207, Class 4. |
Watertightness | To EN 12208, Class E1500. |
Resistance to wind load | To EN 12210, Class 5C (2000 Pa). To EN 12210, Class 4C (1600 Pa) - top swing window. |
Safety | |
Security level | To PAS 24. |
Environmental | |
Background ventilation | Not required. Trickle vents. |
Acoustic performance rating | 33 dB. |
Thermal | |
Whole window U-value | 0.75 W/m²K. Guidance for specification option: Glass U-value: 0.53 W/m²K. |
British Fenestration Rating Council Window Energy Rating | A. |
Frame | |
Profile | Manufacturer guidanceFrame depths from 94 mm to 122 mm, with optional decorative moulding on deeper sections. Consult manufacturer for details and insert requirements. |
Wood species | Pine. Guidance for specification option: Quality class A1–A3. |
Chain of custody | FSC and PEFC. |
Wood finishes | Sprayed, Teknos Aquatop. Guidance for specification option: Consult manufacturer for details and insert requirements. RAL colour. Guidance for specification option: Available in a full range of RAL colours. Consult manufacturer for details and insert requirements. Timber stain, white. Timber stain, grey. Timber stain, clear. Timber stain, light. Timber stain, mid. Timber stain, dark. |
Metal finishes | |
Coating | Polyester powder-coated. |
Colour | RAL colour. Guidance for specification option: Available in a full range of RAL colours. Consult manufacturer for details and insert requirements. |
Film thickness (minimum) | Coating applicator to determine. |
Ventilator | Trickle vent. |
Glazing or infill | |
Requirements | 48 mm triple glazed, two panes Low-E, argon filled. |
Hardware | Hinges, ASSA. Hinges, ROTO. Espagnolette, Fix. Espagnolette, Mila. Espagnolette, Roto. Handles, Fix AB. Handles, Mila. Handles, Hoppe. Handles, Coastal. |
Operation | |
Type | Manual. |
Fixing features | Manufacturer guidanceConsult manufacturer for details and insert requirements. |
Opening | Fixed pane. Top hung. Side hung. Fully reversible. |
Sustainability data
Contains Red List materials | No |
Country of material origin | Europe |
Country of product manufacture | Estonia |
Manufacturing plant location | |
Material | Wood Timber Aluminium |
| Carbon dioxide equivalent | |
Carbon dioxide equivalent, as defined in BS EN 15804 Self-declared | |
Stage Normalised unit (kg CO₂ eq/kg) Declared unit (kg CO₂ eq/m²) Stage:A1–A3 ('Production stage') Normalised unit : 2.429 (kg CO₂ eq/kg) Declared unit : 92.8 Manufacturer guidanceA1-A3 Production stage:
Variable frame depths from 94–122 mm; taking 108 mm as a midpoint yields density of 363.6 kg/m³. | |
Recyclability | Manufacturer guidanceMetal components (aluminium cladding, steel hardware) are recyclable through established collection programs. Glass recyclability depends on local infrastructure. Timber components are recovered for energy use at end-of-life. |
Expected Life | 50 year |
BIM objects
This BIM object has been authored to meet the requirements of the
Find out more about the
| Platform | Compatible | Version |
|---|---|---|
 Revit | - | 1 |
 IFC | - | 1 |
Product certifications
PAS 24
P31 PAS 24:2016 Certificate
Literature
Outward Opening Alu-Clad Window (P31A)
Case studies
Grand Designs & RIBA Award-Winning Retrofit: Ravine House
Award-Winning Yorkshire Passive House
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