Aluminium Double-Sash Window 50 mm Detail (DWG + CAD Drafting)
Aluminium window systems may look simple at first glance, yet incorrect detailing can cause air leakage, water penetration, thermal bridges and long-term operational failures. This technical study provides a complete DWG + CAD detail package for a 50 mm double-sash aluminium window system, including hinge positions, gasket layout, corner keys, reinforcement blocks and full wall interface details.
1. System Overview & Areas of Use
The system illustrated in this detail represents a 50 mm deep, double-sash aluminium window configuration, designed for both architectural clarity and high structural performance. Double-sash aluminium windows in the 50 mm series are among the most commonly used façade and opening solutions because they combine durability, ease of installation, and compatibility with a wide range of insulated glass units.
This system type is preferred in projects where long-term stability, airtightness, thermal insulation and controlled ventilation are required. In modern façade engineering, the 50 mm depth strikes an ideal balance: it provides a slim, elegant appearance while allowing sufficient internal chamber space for thermal breaks, gasket systems, hinge mechanisms and multi-point locking hardware.
Because of its versatile geometry, the 50 mm double-sash system is widely used across multiple building types, including:
- Residential buildings — for balcony doors, French windows, room openings and hybrid ventilation solutions.
- Office buildings — where operable windows are required for natural ventilation in combination with curtain wall systems.
- Hotels, schools, dormitories and high-traffic public structures — due to their durability, repeatable performance and secure opening hardware options.
- Façade infill applications — especially in aluminium curtain walls, where an insulated, operable window unit needs to integrate seamlessly with the façade grid.
In summary, the 50 mm system depth allows the designer to achieve a clean façade appearance while ensuring optimum thermal insulation, weather-tightness, long-term serviceability and compatibility with insulated glass configurations. This makes the double-sash aluminium window one of the most reliable and widely adopted solutions in contemporary building envelope design.
2. Profile Section & Structural Behaviour
The CAD detail breaks the system down into individually numbered aluminium profiles and components, making it easier to understand the structural logic of the 50 mm double-sash aluminium window. Each element contributes to the overall mechanical behaviour, load transfer and long-term performance of the system.
- 1 – Frame Profile: The outer frame acts as the main structural carrier of the window. It receives all external forces — including wind pressure, negative suction, operational loads and the self-weight of the moving sash. The frame also provides the interface to the building wall through mechanical anchors or chemical fasteners. Its geometry allows for gasket channels, drainage paths and thermal insulation zones, ensuring that the window performs as a fully integrated façade component.
- 2 – Sash Profile: The operable sash profile houses the opening hardware such as hinges, espagnolette mechanisms, locking pins and strike plates. It must maintain dimensional stability over time, especially in large openings where sash deflection can lead to air or water leakage. The profile chambers are designed to distribute the load evenly and keep the sash rigid even under repeated use.
- 3 – Glass Bead / Inner Retainer Profile: This component secures the insulated glass unit in place while providing a reliable seating area for internal and external gaskets. Its precision is critical for long-term airtightness and water-tightness because incorrect pressure on the glass or gasket may lead to condensation or air infiltration.
- 4 – Corner Key & Reinforcement Elements: These parts prevent the sash and frame corners from opening, twisting or deforming under load. Corner keys, cleats and mechanical reinforcements ensure that the entire window remains square over time — an essential requirement for correct hinge alignment, smooth operation and gasket compression.
The combined structural behaviour of these components ensures that all forces are properly transmitted along the system: sash → frame → anchorage → building wall. This load path is fundamental to wind resistance, user safety, long-term performance and compliance with façade engineering standards. A correctly designed 50 mm system therefore guarantees stability, minimal deflection and consistent sealing performance throughout the building’s lifespan.
3. Glazing, Gasket Layout & Air–Water Tightness
Functional Sealing Logic
The glazing and sealing design of a 50 mm double-sash aluminium window is one of the most critical factors determining its air permeability, water-tightness and long-term durability. In the CAD detail, all glazing components are individually marked to illustrate the complete sealing logic of the system:
- Inner & outer glazing gaskets: Provide continuous compression on the insulated glass unit, ensuring airtightness and preventing water ingress under pressure.
- Meeting stile (rebate) gasket: Forms the main air–water barrier between the two sashes, reducing infiltration during wind-driven rain.
- Corner blocks & gasket support elements: Maintain gasket continuity at the corners, preventing leakage points where sealing is typically weakest.
- Glass setting blocks: Ensure correct load distribution from the glass to the sash frame, avoiding stress concentration or sash deformation.
- Glass bead interface: Locks the insulated glass unit securely inside the sash while allowing proper gasket compression for thermal and acoustic performance.
Understanding these components and their roles helps designers and installers interpret the sealing mechanism with precision. The detail makes it easy to identify:
- Correct gasket positioning and compression zones — essential for long-term performance and preventing early gasket fatigue.
- How incorrect gasket placement or rotation can lead to air leakage, condensation or water penetration.
- The functional role of the meeting stile gasket in dual-sash systems, where wind pressure creates a critical point of infiltration.
- The interaction between glazing pressure, frame geometry and gasket elasticity, ensuring the system performs consistently across temperature changes and wind loads.
By examining the detail, users gain a clear picture of how air–water tightness is achieved not only through hardware and profile geometry, but also through a carefully engineered multi-level gasket system that absorbs movement, maintains pressure and prevents leakage in every operating condition.
4. Hinges, Hardware & Opening Mechanism
Hinge Geometry & Load Transfer
In a 50 mm double-sash aluminium window system, the hinge layout and opening mechanism determine the structural behaviour, operating comfort and long-term service performance of the entire assembly. Incorrect hinge geometry is one of the main reasons for sash drop, air–water leakage, friction during operation and hardware deformation. For this reason, the CAD detail highlights the complete hardware logic with precise geometric references.
- Precise hinge axis positioning: Every hinge works as a rotational support point. Correct alignment ensures the sash weight is distributed evenly across the frame, preventing diagonal load accumulation and eliminating negative effects such as sagging and binding during opening.
- Primary & secondary sash relationship: In double-sash systems, one sash functions as the active leaf (primary), while the other acts as the passive leaf (secondary). The hinge layout, locking receivers and strike plates are designed to ensure that both sashes compress evenly against their gaskets, maintaining uniform air–water tightness.
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Espagnolette & locking points:
The espagnolette mechanism is positioned to achieve multi-point locking, transmitting closing pressure uniformly along the sash perimeter.
Correct placement guarantees:
- higher wind pressure resistance,
- increased burglary resistance,
- improved noise insulation,
- long-term mechanical stability.
- 1–3 mm operational tolerances: The CAD detail includes clear references for required assembly gaps between sash and frame. Maintaining these tolerances allows the sash to move freely without friction, prevents gasket over-compression, and ensures the hardware performs correctly throughout its lifespan.
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Load transfer from sash → hinge → frame → wall:
The hinge system is responsible for carrying:
- the full weight of the insulated glass unit,
- operational opening/closing forces,
- wind pressure acting on the sash surface.
- Thermal movement & expansion compatibility: Hardware and hinge alignment also consider thermal expansion of aluminium profiles. This ensures that as the material expands or contracts, the sash preserves its geometry without deformation or locking resistance.
Overall, the hinge–hardware assembly shown in the DWG detail provides a complete engineering logic, ensuring the window remains stable, airtight, and easy to operate even after years of use. This is one of the main differences between low-quality installations and professionally engineered aluminium window systems.
5. Wall Interface Details
Thermal, Structural & Airtightness Considerations
The wall interface is one of the most critical areas in any aluminium window installation. Even if the window system is perfectly designed, 60% of failures occur at the wall connection due to incorrect anchoring, poor sealing, thermal bridging or discontinuous insulation. For this reason, the DWG detail includes a fully engineered wall assembly that demonstrates how the window interacts with the building envelope.
- Concrete / masonry wall connections: The CAD detail shows how the frame is anchored to reinforced concrete or masonry substrates. Specific drilling zones, anchor embedment depths and support areas are illustrated to distribute wind load and sash weight without damaging the wall structure.
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A4 stainless steel or chemical anchor positions:
The detail clearly indicates when to use:
- A4 stainless mechanical anchors (corrosion-resistant)
- Chemical anchors (for weak or hollow substrates)
- Galvanized brackets for lateral load transfer
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Thermal break placement to prevent cold bridging:
Incorrect wall–frame contact creates a direct thermal bridge.
The drawing demonstrates:
- how insulation should wrap around the frame perimeter,
- correct placement of rigid insulation boards / mineral wool,
- avoidance of direct aluminium–concrete contact,
- continuity with façade insulation systems.
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Interior & exterior sealant lines:
Two independent sealing lines are shown:
- Exterior seal: UV-resistant silicone or hybrid sealant acting as the first weather barrier.
- Interior sea
6. DWG + CAD Package Contents
- Front elevation (double-sash appearance)
- Bottom, top and side sections
- Hinge & gasket diagrams
- Numbered material overview
- Fully measurable DWG drawings
📥 Downloadable Files
🔗 Useful Tools
- Aluminum Composite Panel Cutting Optimization
- Aluminum Sheet Cutting Optimization
- Capped Curtain Wall Take-Off Calculator
7. Who Should Use This Detail?
- Architects designing aluminium window systems
- Façade and structural engineers
- Fabrication & installation teams
- University architecture & engineering students
- Aluminium system manufacturers & dealers
Conclusion
This complete 50 mm double-sash window detail provides a comprehensive reference for profile geometry, sealing logic, hardware positioning and wall interfaces. It is suitable for façade engineering, education, manufacturing and professional project development, forming part of Arkistral’s expanding “Façade Detail Library”.